,ASSICAL MUSIC OLIMOORS - World Radio History

March/April 1990 $3.50

serving: recording, broadcast and sound contracting fields

Las Vegas Hilton: Redo

Tek Text: elte awdever aze,40, ei441e

Church Audio: on equalization

magazine Broadcast Audio: TV audio in New Zealand

Hot Tips: the evre oj ea,(Ate54244644

Lab Report: Shure Audiomaster 1200

,ASSICAL MUSICOLIMOORS

.Srmphon; OrcheslrJJOVI Lem.; Coo. he m. Wang, OM

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Circle 10 on Reader Service Card

March/April 1990 VOLUME 24 NO.2

Idmagazine

see page 26

see page 56

About the Cover The National Symphony Orches-

tra in performance at the West Lawnin Washington, D.C. See EdLearned's article on outdoor rein-forcement for symphony orchestras,beginning on page 30.

serving: recording, broadcast and sound contracting fields

40teta 4494441444iTHE LAS VEGAS HILTON SHOWROOM AUDIO SYSTEMSteven C. Rypka

THE 1989 NEWPORT JAZZ FESTIVALLarry Zide

EDUCATION IN SOUND REINFORCEMENTRonald Bennett

4

14

26

OUTDOOR SOUND REINFORCMENT FOR SYSMPHONY ORCHESTRA 30Ed Learned

41CREATION OF A CONSOLETy Ford

AUDIO IN THE THEATERRonald Bennett

AUDIO FOR THE CHURCH: EQUALIZATIONBrent Harshbarger

44

E2

LAB REPORT: SHURE MODEL 1200 POWER MIXER AMPLIFIER 59Len Feldman

71 II: CI ri'Ti:inI\111. I I I 1 1^I I II_ I I \III 1_01 I I i-k131_

HOT TIPS: THE ART OF EQUALIZATION: PART IJohn Barilla

19

tzeitskiva, e44154.ceil

BROADCAST AUDIO: NEW ZEALAND: HOME OF THE WORLD'SNEWEST TELEVISION NETWORKRandy Hoffner

CALENDAR

56

2

TEK TEXT: SOUNDLY ENGINEERED A'C: THE ANSWER TO AUDIONOISE 47Martin Glasband

BUYER'S GUIDE: POWER AMPLIFIERS

1990 WINTER NAMM ROUND -UP 74Dan Buxbaum

NEW PRODUCTS 78

CLASSIFIED 80

PEOPLE, PLACES, HAPPENINGS 81

Hereat last!

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DID YOU KNOW?You, our readers, are very important

to us. Should you ever need to contactus about your subscription, please donot hesitate to write to us at:db MagazineAttn: Circulation203 Commack Rd, Suite 1010Commack, NY 11725

HOW TO READ THE LABELThe top line of your label contains

information that enables us to findyou on the computer. Without thatwe can't effect address changes or findyour entry. The sample below is whatmost labels look like.A11 725SAG20 0787 9309Sagamore Publishing Co203 Commack Rd, Suite 1010Commack, NY 11725The first sequence of characters is

how we locate you. The next fournumbers indicate the issue that youhave just received. Finally, the lastfour numbers reversed represent thedate of expiry. Just read backwards:9309 is Sept/Oct 1993.

Synergetic Audio Concepts (Syn-Aud-Con) of Norman, IN, has an-nounced Intelligibility Workshop II tobe conducted under the supervision ofDr. Larry Humes of Indiana Universityin Bloomington, IN, May 24-26, 1990.The workshop will deal with the meas-urement of speech intelligibility and itsuses in planning sound reinforcementsystems with acceptable intelligibilitycharacteristics.

Intelligibility II will employ new tech-nical tools to advance the under-standing of the participants withrespect to the proper measurement of

ech intelligibility of a sound system.speechemphasis will be made to un-

derstand the role of the pinna and earcanal in intelligibility, therefore, hear-ing threshold as well as pinna responsemeasurements will be made on eachparticipant in the workshop. In -The -Ear recordings will be made in the pres-sure zone of the eardrum of severalparticipants of the workshop. DAT re-cordings will be made of 5, 10, 15, 20and 25 percent articulation loss of con-sonants.

Attendance at the IntelligibilityWorkshop will be limited. The work-shop will be held in Bloomington, IN,approximately an hour south of the In-dianapolis airport.

For further information, please con-tact: Synergetic Audio Concepts, R.R.#1, Box 267, Norman, IN 47264.Phone: (812) 995-8212. Fax: (812) 995-2110.

ASTM Committee Meeting on En-vironmental Acoustics (E-33) to beheld on April 30 to May 2 1990, at theStouffer Harborplace Hotel, Bal-timore, MD. For more information,contact Stephen Mawn at (215) 299-5521.

ASTM is also sponsoring a two-daytrainingseminar on ArchitecturalAcosutics. It is designed for architects,designers, engineers, and it includeslaboratory demonstrations and athorough review of fifteen relatedASTM standards.

The 5525.00 fee includes a workbookof lecture notes, all ASTM standardsreferenced in the course, and coffeeand soda breaks.Where: Ottowa, Canada

When: May 14-15

Contact Kathy Dickenson, ASTM,1916 Race Street, Philadelphia, PA19103. Phone (215) 299-5480.

Editor/PublisherLarry Zide

Associate PublisherElaine Zide

Senior EditorJohn Barilla

Editorial AssistantDaniel Buxbaum

Contributing EditorsBruce BartlettBrian BattlesDrew DanielsLen FeldmanRobyn Gately

Randy Hoffner

Graphics & LayoutKaren Cohn

BPA Audit applied for May 1989

db, The Sound Enaineenna Magazine(ISSN 0011-7145)is published bi-monthly by Sagamore Publishing Com-pany Inc. Entire contents copyright 1990 by SagamorePublishing Company Inc., 203 Commack Road, Suite1010, Commack, NY 11725 Telephone' (516)586-6530.db Magazine is published for individuals and firms inprofessional audio recording, broadcast audio-visual,sound reinforcement -contracting, consultants, video rec-ording, film sound, etc. Application for subscriptionshould be made on the subscription form in the rear ofeach issue. Subscriptions are 615.00 per year (628.00per year outside U.S. Possessions, 616.00 per year inCanada)and payable in U.S funds. Single copies are63.50 each. Editorial, Publishing, and Sales offices areat 203 Commack Road, Suite 1010, Commack NY11725. Second Class postage paid at Commack, NY11725 and an additional mailing office. Postmaster:Form 3579 should be seM to db Magazine, 203 Com-mack Road, Suite 1010, Commack, NY 11725.

Trademarked names are editorially used throughoutthis issue. Rather than place a trademark symbol nextto each occurance, we state that these names are usedonly in an editorial fashion and to the benefit of thetrademark owner, and that there is no intention of trade-mark infrinaement

fit I Ile I 1111 111.6111 %Pie( t Budd UPer 411P I mho!

Test Our IQ.Install Crown's new IQ System 2000,'"

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It's the incredible new IQ System 2000 fromCrown. Using a common personalcomputer, easy -to -installIQ components,and Com-Tech"amplifiers, youcan now do in minuteswhat used to take days. IQ Interface, Software & P.I.P. Module

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219/294-8000Circle 14 on Reader Service Card

STEVEN C. RYPKA

The Las Vegas HiltonShowroom Audio System

Sound reinforcement systems are becoming increasingly sophisticated as demonstrated by thenew installation in the Las Vegas Hilton's main showroom.

As the Hilton's head audioengineer for the past eightyears, I have tried to im-prove the performance of

the showroom audio system when-ever possible. Many of these im-provements were made possiblewith the help of audio technicianBud Wolfe, the other half of theshowroom sound crew. We re-cently finished a major up-grade of the front of house sys-tem that uses some newdevelopments in both hard-ware and software to achievemany interesting capabilities.

A LITTLE BACKGROUNDAlthough the showroom in

the Las Vegas Hilton is thelargest in Nevada, it is a fairlyintimate venue. The roomseats approximately 1,600 per-sons, with about 375 of thoseseats located in a balcony. Thestage is large, with a 65 -footmain curtain in the centerwith 30 -foot side stages oneach side, and is about 85 feetdeep. The house sound booth,ideally located, is on the centerline of the auditorium and just un-derneath the front edge of the bal-cony. A custom frame houses six 24 -inch -tall racks of outboard gear andprovides support for two YamahaPM -3000 consoles.

The 32 -channel console's auxili-ary, group, and stereo bus outputsare normalled to the respective sub -inputs of the 40 -channel console'sbuses. The master Mute and VCAcontrols can be operated inde-pendently or as one master sectionthat controls both boards (fromeither console). This 72 -input con-

-,r figuration allows great flexibility for

large shows, co -headliners, andspecial events.

Effects devices include an Even-tide H3000 Ultra -Harmonizer, aLexicon PCM-70, two Yamaha REV -5's, and two Yamaha SPX -90 II's.These units are linked via MIDI to aLexicon MRC midi remote control -

Figure 1. A view of the Las Vegas Hilton Showroomstage and speaker rigging from the double consoleposition.

ler, allowing quick program changesof all units simultaneously. There aretwo dbx 166 gated compres-sor/limiters and two dbx 900 racksequipped with eight 903 compres-sors, nine 904 noise gates, and a 902de-eqsPr.

A twenty row by twenty-six posi-tion patchbay allows flexible equip-ment configurations and includesmic lines from both 50 -pair snakes(custom built by A-1 Audio) as wellas nearly 100 additional mic linesfrom other parts of the room. Tapemachines include an Otari MX-5050-BQ-II 4 -track reel -to- reel, aBroadcast Electronics Five -slot cart

machine, and a Nakamichi cassettedeck.

A third PM -3000 (40 channel) isused as a monitor board. The moni-tor system contains 12 Klark-TeknikDN-3601,A3 octave equalizers, 4 TDM24CX-4 crossovers, and 14 Crest4001 power amplifiers. An assort-

ment of bi-amplified wedgesinclude Meyer UM -1's andcustom cabinets using JBLcomponents. These cabinetswere fabricated by A-1 Audioand include both single 15 -inch and double 12 -inch con-figurations, all with 2 -inchcompression drivers. Theside -fill system consists of twoMeyer MSL-3 cabinets, eachmounted on top of a MeyerUSW-1 subwoofer cabinet.

A wide selection of micro-phones includes models fromAKG, Beyer -Dynamic, Coun-tryman, Crown, Electro-Voice, Mylab, Sennheiser,Shure, and Yamaha. This con-figuration of the house sound -booth and monitor system hasbeen functional for about twoyears.

A NEW PROJECTThe latest improvement to our sys-

tem was a complete upgrade of thefront -of -house components, includ-ing equalizers, delays, crossovers,amplifiers, and the weakest link inthe chain, the speakers. More than ayear of research included gatheringinformation, studying new equip-ment, and discussions with othersound engineers that came to theHilton. Some of our best informationcame from these outside engineers,who shared their thoughts and ideason what would constitute the bestpossible system.

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The decision was made to do thisproject completely in-house, for thefollowing reasons; we had the fullsupport of Hilton management, wewould be able to make the most ofour budget by utilizing in-houselabor, and the technical knowledgeand ability of our crew was top-notch. We received the news of ourbudget approval in late July of 1989.From that point on we went intohigh gear. The design goals of theproject were fairly basic: full -rangefrequency response, smoother cover-age throughout the room, increaseddynamic range (headroom), andmaximum flexibility of the system.

SPEAKER SELECTIONThe first decision concerned which

type(s) of speakers to use. I decidedto utilize a full -range, pre -designed,arrayable speaker cabinet systemrather than trying to form coherentarrays from lots of separate com-ponents as was previously done. Tohelp make the final decision on themain cabinets, I was able to arrangea "shootout" on the Hilton stage be-tween four different manufacturer'sspeaker systems.

Although none of the systemstested performed poorly, we choosethe 'Eastern Acoustic Works KF-850system for its natural, clear sound,and smooth coupling (equipped withfactory -standard RCF drivers formids and lows, TAD 4001 drivers forthe highs). Matching E.A.W. SB-850double 18 -inch subwoofer cabinetswere chosen to extend the main sys-tem to the lower octaves. We decidedto use Meyer Sound Laboratories650-R2 double 18 -inch subwoofersfor our separate sub -bass effects sys-tem in the side walls.

Apogee Sound AE -2 loudspeakerswere chosen to cover our under -hal-

o cony areas. These speakers have re -

Figure 2. A closerview of the housesound booth show-ing the effectsracks below theconsole and, at topleft, the controlcomputer.

markable punch and clarity in asmall, low -profile design. In addi-tion, the smaller E.A.W. KF-300speakers were specified for both rearwall effects and for overhead fillspeakers directly over the front edgeof the stage.

ELECTRONICS SELECTIONFor a number of years I have been

deeply involved with personal com-puters and programming and hadbeen looking for ways to incorporatethe power of a personal computerinto the everyday operation of alarge sound system. When I learnedabout the Crown IQ system, whichuses a computer to control and moni-tor multiple amplifiers, I knewthings would never be the same. Theengineers at Crown have come upwith a very valuable tool that pointsto the future of modern sound sys-tems. Further research and ABcomparisons with other "industrystandard" amplifiers confirmed thehigh quality of the Macro -Techamps. The Crown products werechosen to power our new system.

T.C. Electronics 1128 V3 octaveprogrammable equalizers werechosen for their excellent audio qu-ality as well as their many otherpowerful and unique features. If ournew system was to be flexible, I feltthat the equalizers used for the frontof house system had to be more thanthe standard manual V3 octavegraphic. Storage and recall of presetcurves would enable any engineer tohave his exact EQ settings, and stillhave my standard "house" EQcurves available when needed. The1128s also have a well -executedcomputer interface that makes themeven easier to use.

We followed the manufacturer'srecommendations concerning fre-quency dividing networks (or pro-

cessors): E.A.W. MX -800 units forthe E.A.W. KF-850/SB -850 cabinets,BSS FDS -360 units for the KF-300speakers, and devices from Meyerand Apogee for each of their respec-tive speaker systems. Klark-Teknikdigital delays were selected for thetwo -zone under -balcony system andfor the side and rear effects sends.

SYSTEM DESIGNThe previous sound system in-

cluded three overhead clusters, left,cente4 and right. The components ofthat system were stacked on steelplatforms that hung approximatelytwenty-four feet above the edge ofthe stage. In addition, there werespeakers for side and rear effectsand a 70 -volt under -balcony system.Since the old clusters were alreadyideally located, we maintained thesame basic positioning, improvingthe coverage, zoning, and of course,the components themselves. It wasdecided that each overhead clusterwould contain four KF-850 cabinets,two for the balcony and two for themiddle of the main floor. Eachcluster would also contain two KF-300 cabinets aimed almost straightdown as near -fill for the area just infront of the stage. The left and rightclusters would also house four SB -850 subwoofer cabinets each.

An additional set of two KF-850and two SB -850 stacks werespecified for each side of the stage tobe used as an optional stage -level fillsystem. This was done to satisfythose engineers who required alower image source for their mix.The under -balcony coverage splitthe ten Apogee AE -2 speakers intotwo separate delay zones of six andfour cabinets each. Two Meyer 650-R2 subwoofers and one KF-850 cabi-net were designated for sub -bass andside wall effects. Four additional KF-300 cabinets were specified for therear wall effects system.

Since maximum zone control wasnecessary to attain the smoothestcoverage, we used one amp channelper driver throughout most of thesystem. The only exceptions to thisare the two 18 -inch drivers in eachsubwoofer cabinet which are drivenby one amp channel, and the mo-naural under -balcony system wherewe use a total of four amp channelsfor the ten 16 -ohm AE -2's. CrownMA -1200 amplifiers were assignedto power all high -frequency driverswith MA -2400's for the mids, lows,

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Airports, bLs terminals Spoils and recreational

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It combMes the technology ofprcrfessi3nal acoustics with theconvenience and architecturalintegrity of conventional ceil-ing installations.The 50 watt loudspeaker sys-tem consists of a high perform-ance 8' dia. 1.3w frequencyreproducer and a 4" dia. highfrequency pieszo transducerhoused Nithin a ported bassreflex ceiling enclosure whichachieves optimum responseanc system resonance. 17reqJires no 'monetaryelectron cs.

6,57-"iii'v is aestheticallypleasing cost effective, andthe new aerfo-mance standardfor high quality distributedsound systems from:

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and subs. We specified a total ofeighteen E.A.W. KF-850's, twelveSB-850's, ten ICF-300's, ten ApogeeAE -2's, four Meyer 650-R2's, andthirteen Crown Macro -Tech MA-

1200 and 33 MA -2400 amplifiers. Anew, computer -grade, three phase,112 KVA isolation transformer wasordered to provide over 300 amps ofclean A.C. power to the system in-cluding a 200 amp disconnect, usedto supply external A.C. power dis-tribution systems.

With the new capabilities of theCrown IQ system, we decided to lo-cate the amplifiers as close to thespeakers as possible. The short cableruns would maximize power trans-fer and damping factor, giving us thebest possible performance, while theIQ system would enable us to main-tain total control over the remotelyinstalled amps. Since most of thesystem would be over the stage, weneeded a home for five racks total-ling twenty-eight amplifiers. Thisled to the design and construction oftwo overhead amp rooms locateddirectly above the left and right mainclusters.

Along the way, a new product wasbrought to my attention that wasvery interesting. The device, calledB.A.S.E. which stands for Bedini

Figure 3. An. ex-ample of onecluster of the KF-850s, this one atthe house right.The author is seenmaking adust-»tents to therig.

Audio Spatial Environment, wastested on the old sound system andproved to be a fabulous device thatreally worked as claimed. The unitenhances stereo signals, giving agreater sense of depth and texture tothe mix. Since the Hilton Showroomlends itself well to stereo sound, andthe B.A.S.E. units actually enhanceseparation for more of the audience,three units were incorporated intothe system.

As this design was finalized, allaspects of the system were drawn onthe computer using CAD software(see example). Multi -pair wiringconnections, to be done on telephonepunch blocks, were laid out onspreadsheets that contained a de-scription of every wire's function, itscolor code, and number. Price infor-mation was also stored in a spread-sheet, enabling us to track our pro-gress and optimize the systemdesign while staying within thebudget.

THE ACTUAL INSTALLATIONThe entire project spanned a six-

month period and consisted of manydifferent phases, many of whichoverlapped considerably. We actuallystarted the installation shortly afterour budget approval, even though

the design was far from complete. Iused project management softwareto help schedule the different seg-ments of the job. The actual hangingof the clusters was scheduled for adark period in Decembei just priorto Christmas. Because we had thetime, Mr. Wolfe and I were able to domost of the wiring work ourselves.Our intimate knowledge of the ex-isting system enabled us to makegood use of existing conduit runs.Thousands of feet of old speakercable were removed from its conduitto make way for the A.C. and line -level runs to the new overhead amprooms. An electrical contractor washired to install the new A.C. isolationtransformer and a 400 amp discon-nect to feed it.

Using our spreadsheet layouts ofthe punch blocks, the multi -pair line -level connections were made. Thisprocess went very smoothly, havingbeen triple -checked on the computerprior to installation. The A.C. powerrequirements of the amplifiers werecalculated and each portion of thesystem was balanced between thethree phases. Three separate 30 ampA.C. circuits were pulled to each am-plifier rack.

Seven T.C. Electronics 1128 unitswere installed in the house booth forequalizing the three main clusters,under -balcony system, stereo effectssystem, and a patchable spare.Another addition was the NorthgateComputer Systems 20 MHz 80386computer equipped with 4 MB ofRAM, a 67 MB hard disk drive, ahigh -resolution mouse, and a colorVGA monitor. The remaining elec-tronics, (EQ's, delays, and cross-overs) were installed in a rack onstage left.

When the E.A.W. shipment arrivedin Las Vegas at A-1 Audio (a majorvendor for the system), the speakerswere stored in their warehouse. A-1graciously let us use their facility forpre -testing of the speakers. A TEFanalyze4 brought in by Steve Jamesand Jim Fox of Electro-Acoustics inLas Vegas, was used to confirm theresponse and proper polarity of allthe drivers.

In December; the old system wastaken down and the new one washung. The rigging design uses aswivel-frame/trolley assembly at-tached to a structural I-beam. Thisallows each cluster (four cabinets pertrolley sgsPmbly) to be pulled backover the steel floor and then swiveled

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ninety degrees for necessary main-tenance. Before installing the IQ sys-tem software, we tuned the systemfora maximum operating level using

Figure 4. Theseracks of CrownMacro -Tech ampsare one of twosuch located over-head, just abovethe house rightcluster

Figure 5. A com-puter drawing bythe author of thehouse left maincluster

the amplifier inputs, adjusting thegains so that even without the com-puter control, the system would de-fault to the manually set levels.

Limiter thresholds in the variousprocessors were set to allow maxi-mum safe operating levels beforelimiting.

HOW WELL DOES IT WORK?I feel that all of our goals for this

project have been met and that thenew audio system performs as ex-pected. Very little equalization isnecessary to get a smooth, fullsound. Reaction of audiences, enter-tainers, and engineers has been ex-tremely positive. The system is veryquiet, yet will cleanly reproduce thepeaks of a live show with ease. Thereal news, in my opinion, is the flexi-bility and control that the computerhas brought to the system.

Now we can use the IQ system toload a preset from the disk to con-figure the amplifier settings for theentire room in a matter of seconds. Ifwe have a full house, we run withzero attenuation; if the balcony isempty, we attenuate the amplifierchannels driving that part of theroom. We no longer have just onemode of operation for every show,and every show has the potential tosound just that much better. The re-peatability of these settings is pre-cise.

We can also monitor every ampli-fier's operation, from the soundbooth, and know exactly how muchheadroom we have or if there is aproblem with part of the system. Ican mute every amplifier, feed pinknoise to all outputs, then un-muteeach amp channel momentarily insuccession to verify the operation ofevery driver in the system in a mat-ter of minutes.

Using the computer to control theT.C. Electronics equalizers is also awonderful experience. The ability tosave and load presets of a complexequalization curve is marvelous. Forexample, before changing a curve itcan be copied it to a new address.Then it can be altered and comparedto the original by switching back andforth. Other benefits include theability of the computer to calculateand trace the additive effects of eachband's setting; and the integral spec-trum analyzer for each unit that willshow you problem frequencies im-mediately. Having all of this capabil-ity on a color monitor that you canread easily under almost any light-ing condition is fantastic. co

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I have set up the computer withmulti -tasking software calledDESQview 386 from Quarterdeck

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Office Systems. This windowingcontrol program allows me to runmany programs at once on the 386

machine. One window can run theCrown IQ System software, while atthe same time another window isrunning the T.C. Electronics pro-gram. Switching between programsis instantaneous and both windowscan be displayed simultaneously ifnecessary.

An additional Sequencer/Edi-tor/Librarian program controlling aMIDI interface card is now con-nected to our six effects devices. Thisallows saving of all user presets todisk for future retrieval, as well asperforming complex programchanges in real-time during a show.We all know that computers are nottotally infallible, in fact they can bevery susceptible to power surges andother problems. Because of this, wehave incorporated this technology insuch a way that if something shouldgo wrong with the computer, the sys-tem will still be 100 -percent oper-ational.

CONCLUSIONThe marriage of new audio equip-

ment with the PC has increased thecapabilities of our sound system tre-mendously. The audio quality of the

Why our first stage monitor

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new system is excellent, with plentyof headroom for any live perform-ance. All of this power, used crea-

tively and with taste, can greatly en-hance the enjoyment of our show-room customers, and make the en-

gineer's job that much more enjoya-ble and fulfilling.

Las Vegas Hilton Showroom Sound System SpecificationsHOUSE SOUND EQUIPMENT

House Sound Booth:There are two Yamaha PM -3000

consoles (one 40 -channel and one32 -channel) with all 72 channel in-puts, plus 6 stereo aux returns avail-able. Theqe consoles can operate in-dependently or linked together,sharing VCA and mute masters, auxand stereo bus outputs. The soundbooth is centrally located in an idealposition.

Processing devices availableinclude:

2 dbx 166 gate/compres-sor/limiters

6 dbx 903 compressor/limiters9 dbx 904 noise gates1 dbx 902 de-esspr

Effects devices availableinclude:

1 Eventide H3000 Ultra -Har-monizer

1 Lexicon PCM-702 Yamaha REV -5's2 Yamaha SPX -90 II's

Tape Machines availableinclude:

1 Otari MX-5050-BQ-11,4 -track reel-to-reel

1 Broadcast Electronics 6 slotcart machine

1 Nakamichi auto -reverse cas-sette deck

Main PA System:The PA system consists of three

overhead clusters (left, center, andright). Each cluster consists of fourEastern Acoustic Works (E.A.W.)KF-850 (large, 3 -way, tri-amped, fullrange) cabinets and two E.A.W. KF-300 (small, 3 -way, bi-amped, fullrange) cabinets. The left and rightclusters also have four E.A.W. SB-

850 (double 18 -inch) subwoofer cabi-nets each.

Optional, stage level, left and rightstacks consist of two E.A.W. KF-850and two E.A.W. SB-850 cabinets perside.

The under -balcony system is a mo-naural composite of the left/rightstereo mix, in two delay zones, con-sisting of a total cf ten Apogee AE -2under -balcony speakers.

A separate aux bus feeds a sub -bassenhancement system consisting offour Meyer 650-R2 cabinets locatedin the side walls of the showroom.

Another aux bus feeds a surround -sound effects system consisting oftwo E.A.W. KF-850 cabinets (sidewalls) and four E.A.W. KF-300 cabi-nets (rear wall).

console may well be your last.

\WA \\\itt g g 1'1 lit it lit sk i&

In a world where today's hits often become tomcrmw's Muzak;"it refreshing to find the Yamaha PM2800M Monitor Conscle.

Because it -las what it takes for a long stage life. Like 14 mixes.Four matrix outr uts. Meters for each primary output Four bandvariable EQ. 20 to 400 HZ pass filter. And it's available in either 32 or40 input versions..

To improve your stage presence, it has Pr gran mable MuteGroups. They let you switch large groups of channels on or off, silently.

The PM2800M also lets you change your act without changingconsoles. Because it's a stage mixer that also can double as ahouse mixer.

And, its a Yamaha. Built with a commitment to Tliabilitythat'llmake it one of the few things on stage that isn't temperamental.

For an audi-ion, just stop by any Yamaha ProfessionalAudio dealer.

But do it soon. Because even though the PM2800M is built tolast, it tends togs quickly in the showroom.Yamaha Corporation of Amer ca, Pn n. P.O. Box 6600, Buena Park, C.s 90622-6,300. In Canada,Yamaha Canada Music Ltd., 35 Al liner Aver ue, N. -arbor, nigh, Ontario MIS3R1. Muzak' is a registered trademark ofMuzak.

YAMAHAEngineering Imagination'

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MONITOR EQUIPMENTThere is one 40 -channel Yamaha

PM -3000 console, providing ninediscrete mixes and eight additionalmixes via the Matrix outputs. Thereare twelve Klark-Teknik 1/3 octaveequalizers and twelve bi-ampspeaker outputs. There is oneYamaha SPX -90 II signal processoravailable.

Monitor speakers available in-clude:

4 JBL bi-amped, 3 -way, single 15 -inch wedges (A-1 Audio design)

4 JBL bi-amped, 2 -way, double12 -inch wedges (A-1 Audio design)

4 Meyer bi-amped, 2 -way, UM -1wedges

2 Meyer bi-amped, 2 -way, MSL-3side fills

STUDER REVOXDEMO/USED/TRADE-INEQUIPMENT FOR SALESTUDER PRODUCTS LOCATION EACH QTY.D820X DASH Digital Demo \.),I i% illt S19,000 (1)A820-24 Demo Ncw York 54.0(X) (1)A820-2-1/4" TC Demo 12,0(X) (1)A812-2-1/4" TC Demo 11,000 (I)A810-2-1/4" Demo ( w/console) \c\\ »is 7,500 (I)A810-2-0.75 Demo ( w/console ) \ 4,11\ -ilk. 6,900 (1)A810-2-0.75 Demo N.).11\ 5,900 (1)A810-2-1/4" TC Demo (w/console)N,Is11 8,900 (1)A807-2-1/4" Demo (rackmount) N,t11\ 3,900 (1)A730 CD Player Demo N..),11% 2,500 (3)A727 CD Player Demo Nash\ 1,950 (2)A725 CD Player Used Nashville 750 (8)A8ORC-2-1/2" New Nashville 8,50() (1)A67 (w/console) Used Nashville 750 (I)Console 269 15in/3 out Demo Los Angeles 9,900 ( )

B67 -1/4" -Pilot Demo Los Angeles 6,900 (2)TLS -2000 New Nashville 3.900 (2)TIS-4000 Nashville 3,250 ( ))

REVOX PRODUCTSC278-8 Track Demo \,,-,11% 55,950 ( 1)

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OTHER BRANDSAmpex MM -1200 Used 16-Trk Nashville 6,900 (3)Otari MTR-90 Used New York 33,900 (1)

Products are offered subject to prior sale. Studer Revox demo pro-ducts sold with original limited warranty. Other products sold asis hut cleaned, tested and aligned, and in some cases refurbished.Cash before delivery. Sales taxes are additional. F.O.B. wherelocated. Financing assistance and monthly rentals available.Please call the Studer office nearest you for the details:

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2 Meyer subwoofers, double 15 -inch (part of side fill system)

2 Yamaha 2115's, full range, 2 -way wedges

2 Yamaha 4115's full range, 2 -way, self -powered

Snakes:There are two custom 50 -pair

snakes, each equipped with multiplesub -snakes off the main box. Eachbox has a hard -wired split with in-dividual ground -lift switches on the"B" side of each pair. One snake nor-mals into each house console. Tailsare provided for patching into themonitor console(s).

Microphones:There is a large assortment of mi-

crophones from: Beyer, Shure Bros.,AKG, Sennheisei Countryman,Yamaha, and Electro-Voice. Thereare eight passive direct boxes, allwith Jensen transformers, and sixactive Countryman direct boxes.

A.C. Power:There is a 112 KVA computer -

grade isolation transformer provid-ing power to the entire sound sys-tem. The transformer also feeds a200 amp, 3 -phase disconnect box lo-cated on stage left for connecting ex-ternal A.C. power distribution sys-tems.

Communications:There is a multiple channel Clear-

Com headset system throughout theshowroom. Communication chan-nels exist between all lighting per-sonnel, the fly rail, the stagemanager, etc. A private line exists foraudio communications only.

Miscellaneous notes:All house speakers are driven by

Crown Macro -Tech power amplifi-ers (MA -1200 for highs, MA -2400for mids and lows). The system is ex-tremely powerful (over 40,000watts), accurate, and has sufficientheadroom for any type of music.Coverage is very uniformthroughout the room. All main housefeeds are via T.C. Electronics 1128programmable equalizers. All KF-850 cabinets are equipped with TADhigh -frequency compression drivers.All effects devices are controlled viathe MIDI interface allowing maxi-mum flexibility and quick programchanges. All monitor speakers aredriven by Crest power amplifiers.

1200 WATTS, FOUR INDEPENDENT CHANNELS,FLEXIBLE, 2/3/4 CHANNEL SELECTABLE...

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Circle Reader Service Card # for200 -watt Amplifier Comparison Chartand 1989 Buyer's Guide to ProfessionalProducts, with Specs and Prices.

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LARRY ZIDE

The 1989Newport Jazz Festival

This year's festival, heldAugust 17th to the 20th,is the thirty-fifth in a ser-ies. It has been a rocky

series, having been driven fromconservative Newport, Rhode Is-land by large crowds in the late60s, brought by the likes of JethroTull and Led Zeppelin. In 1971,large crowds coming for the rock,rather than the jazz concerts toredown fences surrounding the con-cert venue, bringing about the ban.

So, in 1972, it became the New-port Jazz Festival-New York andit was that until 1981. For thoseten years in the Big Apple, the Fes-tival was presented in CarnegieHall, later Lincoln Center, but alsoYankee Stadium, and even once,on the Staten Island Ferry.

Figure 1. The tennis court set up as viewed from, the stage.

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The lure of Newport, howevei re-mained. According to long-time Fes-tival produce4 George Wein, "Thethought of coming back was very ap-pealing, so we approached the Stateof Rhode Island and the city counciland found that most people were re-ceptive to our coming back."Starting in 1981, the Newport JazzFestival was back in Newport, RI.

THE 1989 FESTIVALThe Friday night concert was

again held at the Newport Casino,the 19th century tennis club (nowalso the site of the Tennis Hall ofFame,) where the first concert washeld. Audio and video equipmentwas being set up on center court. Wehad arrived in the early afternoon tomeet with John Philips of FestivalProductions, who with the sponsor-ship of JVC, were supervising the in-stallations. We were also scheduledto meet with Gene Shively, of CMF.Gene would be making a digital tapeof the event for JVC. A twenty-fourtrack analog master also was beingmade-all this in conjunction withthe video taping for the broadcast inNovembe>y 1989 that was on PBS.

A massive Unitel truck was parkedjust outside the center -court area,


1990 Editorial Calendar

,JAN/FER

The Professional Electronic Cottage and Broadcast USA-a SynergeticCombination!

Winter NAMM and NAB show issueGUIDE:

Speakers: performance & monitor

MAR /APR

Sound Reinforcement: theory, and application for various venues-NSCAshow issue

GUIDE:Power Amplifiers

MAY/JUNE

Broadcast, Recording & Sound Reinforcement in Houses of WorshipSummer NAMM issue

GUIDE:Consoles & Mixers

JULY/AUG

Live Sound-producing it and,or recording it.GUIDE:

Tape, tape recorders and accessories, Microphones

SEPT/OCT

Audio Post-Production-Television and FilmAES in L.A. Show issue

GUIDE:Signal Processing Equipment, Part I

NOV/DEC

The Recording Studio-What's happening, what's aheadGUIDE:

Signal Processing Equipment, Part II, Studio Accessories01

Figure 2. The mix point for the tennis court set up is seen at the left inthis view toward the stage.

and cables were being strung to thestage area for the audio, video andlights. The truck also contained afair-sized section just for audio -24track Otari MTR-90 and bigAuditronics 48/24 -bus console.Unitel's Terry L. Kulchai Senior

Audio Engineei but known as"Tweetei" explained the truck."This is the video and audio master-ing for the PBS television broadcast-ing, editing and audio sweetening tobe done later. In addition to theAuditronics 750, we've got six

Yamaha 1M406 6/2 submixers. Moni-tors are Visionik-80 monitors withsubwoofers powered by Crown D-150 amps. We have two dbx 160X,two UREI 1178s, and an Aphex 300stereo compressor/limiter, a dbx 904noisegate, and a Lexicon L-200 digi-tal reverb as standard. We also havean Otari 5050 II I/4 -in. and a Tech-nics cassette deck for on the road in-stant demos."

LIVE SOUNDJoe Shalhoup did the mix from

mid -court (see Figure 2.) He ex-plained the setup for the concert."I'm using a small console and twoequipment racks to create a monomix for the audience. I work for Ca-pron of Boston and we are doing allthe concerts. It's a separate setup,different from here, that will be usedat the Saturday and Sunday con-certs. But this one has the two bigMeyers, fed by Crowns for the mainsound. The bleachers in back, how -even are being faced by five E -Vunits. This supplementary systemshas 150 ms delay.

"The stage has six Capron -built E -V -component stage monitors along

Circle 23 on Reade.. Serv'ce Card

Figure 3. The mix console position has a clear view of the stage.

with two Meyer side fills. We areusing Shure, Sennheiser, and AKGmics on stage along with four moreSennheisers aimed at the sides andfrom the front for audience reaction.There are also Countryman boxesand C-Ducer contacts for the instru-

ments. We're not using any wirelessmics."

"I'll be giving the sixteen -channelfeed to the Unitel Truck from here aswell as handling the live sound.

We asked how he handled the all -to -frequent requests from artist

people to take over the soundmixing.

"More often than not when thathappens, and its not really thatoften, I'll explain how I know thisequipment and can really do the bestjob for them. But if their soundmanreally seems to know the equipmentand how to use it (I can determinethat in a few minutes,) then I'm per-fectly willing to sit back and let himdo it."

The sound check by artist MelTorme went well. We could not stayfor the concerts.

EQUIPMENT LIST (STAGESOUND)

Console:Yamaha M1516

Microphones:Shure, Sennh(ise4 AKG wiredCountryman direct boxesC-Ducer contact mics

OR, FOR JUST $13,999YOU COULD BUYA NEW MSR-2 .

Maybe at one tirne it was worth rsking second-hand sound, iffyreliability and outmoded technology to save money on a used 24 -track.

Not any more.At $13,999,* the MSR-24 actually costs thousands less than most used

machines. And its cost-effective one inch format saves you even more.But despite its low price, the MSR-24 has micro -electronically con-

trolled functions that recorders even a year or two old can't match.And when it comes to lock -up speed, no usedmachine can compete.

Best of all, the MSR-24's incrediblesound will knock you out, thanks to fea-ureslike our superior head design, gapless punchin/out and spot erase. And, of course, youalso get Tascam's legendary reliability

See your Tascam dealer and try out thebrand-new very affordableMSR-24. And et Al <eepthe hand -rte -downs. Manufacturer's si_gpe-ted retail price

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Figure 4. The mix console sits on one of two portable equalization, play-back, and amplification racks.

EQ:Klark-Technik 3rd -octave

Aphex Aural Exciter, Type C

Compressors and Limiters,Delays:

Brooke Siren stereo limiter

Lexicon Prime Time

Other equipment:Furman power conditioners

Tascam MK II cassette deck

Teac CD player

IF YOU'RE THINKING OF BUYINGAN 8 -TRACK, MAYBE YOU SHOULD

THINK TWICE.Think 16 tracks.Think

MSR-16. Because for around$750Q* you get a full 16 tracksfor just a ittle more than youraverage 8-track.Which dou-bles your capabilities. All in acost effective'/2-inch format.

Whet's more,the MSR-15 isloaded with fea-tures usually foundon units selling fortwice the price.

Like a rehearsemode that allows

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Plus, our exclusive circuitryassures gapless, punch-in/out,and spot erase capabilities.

The MSR-16 is now play-ing at your localTascam dealer. Sograb your check-book, and headon down. It's adeal you won'thave to thinktwice about.

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JOHN BARILLA

The Art Of Equalization : Part 1 The difference between an out-

standing audio mix and a mediocreone often boils down to subtle differ-ences in equalization. A just barelyaudible boost or cut at key frequen-cies can often turn an otherwise life-less series of sounds into a brilliantsonic picture.

Likewise, a mix can quickly turnharsh and unlistenable if equaliza-tion has been excessively applied.How do we know where to start andas importantly, when to stop?

It has often been argued that a per-son either has "ears"-that is, acutesonic awareness-or doesn't; thatwhile you can teach someone tooperate a recording studio, you can'tteach him aesthetics. But this eli-tism/defeatism attitude is patentlyfalse. While certain people are in-nately more talented in this areathen others, every sound engineershould be able to master the art ofequalization by assiduously applyingthe basic principles presented in thisarticle. Herein lies the true art ofequalization.

WHAT IS EQUALIZATION?Does that sound like too elemen-

tary a question for you? Think aboutit for a moment. Today, equalizationis often pragmatically defined: it iswhatsoever you decide to do withthose knobs on your mixing consolewhich are called equalizers. This ap-proach is pretty much underscoredby our consistent use of the acronym"EQ", instead of the word "equaliza-tion." Of course, EQ is much easierto say, but it fails to remind us ofwhat we should be doing when we

dB12

6

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-1220 200 1K 5K 10K 20K

Frequency in HertzFigure I. A representation of shelv-ing equalization.

twiddle those knobs: equalizing, orcompensating for perceived deficien-cies in the sound-relative to thepurpose of the sound in it's context.

Am I advocating a philosophy ofequalization that merely strives tocapture the sound and never tomanipulate it? Certainly not!

While there are times when faith-fulness to reality is the rule (for ex-ample, live classical recording), inmost cases, equalizers can validly beused as a creative tool for sonicmanipulation-a first -order signalprocessor of more power and utilitythan reverb and delay. If the contextdemands a snare drum with moresnap than a live drum, or one that adrum sample is capable of deliver-ing, we can respond by exaggeratinga peak inherently in the drum, or

perhaps, even creating one at sometotally unnatural frequency.

This use of equalization-even if itresults in a bizarre sound-can bevalid because it compensates for theperceived deficiency of the source,relative to the context in which it willbe placed.

The dangerous "thin ice" ofEQ'ing howeve4 is in arbitrarinessand subjectivity. When one startsmaking rules like, "I always addhighs, because highs make every-thing sound better," he is headed foran artless, perhaps even abrasive re-cording that may seem at first titil-lating, but will not hold up under re-peated listenings. No, the art ofequalization is nowhere to be foundin subjective judgements or rigidrules. Like any art, mastery is to befound in truly understanding thetools and the medium in which youare working.

INEQUALITY AMONGSTEQUALIZERS

All equalizers are not equal in thekind of performance they are suitedto deliver. Most of this is a function ofthe design criteria: what the manu-

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facturer has determined are the besttrade-offs for its market. Practicallyspeaking, equalizers are meant to dospecific things, to the exclusion ofother things. So boosting 5 kHz onone manufacturer's recording con-sole may not have the identical soniceffect as the same degree of boost onanother brand. We will address thisissue again, but for now, let's leaveaside the nuances of different manu-facturers and review the operationalsimilarities of the basic types ofequalizers.

SHELVING EQUALIZERSThe antipodes of the audio spec-

trum-the low and high end-havethe unique ability to add warmth orbrilliance to a sound. This is achievedmost subtly when a wide range of lowor high frequencies are affectedsimultaneously, rather than specificfrequencies. Shelving equalizers aredesigned to perform this task. Fig-ure 1 shows a graphic representationof this. It is quite apparent why thistype of curve is called a "shelving"curve, for it appears to be lifting (orlowering) the entire low or high endas though it were on a platform or"shelf." This lift is applied uniformlyto all frequencies below or abovewhat is called the "turnover point":the place where the curve begins toflatten out. The turnover point isusually in the neighborhood of 10 kfor a high shelf and about 200 Hz fora low shelf.

Shelving equalizers have manygood features to commend them tothe user, not the least of which is thatthey are "smooth" to the ear andvery easy to apply or remove from amix. They allow a sound to retainmuch of it's characteristic definition(which is most often a mid -rangefunction), while gently stretching itat the ends. It is difficult to per-manently screw -up a sound with ashelving equalizer. Unfortunatelythough, with the following two typesof equalizers, this is not the case.

PEAKING EQUALIZERSIf you want to boost or cut a dis-

crete area of the sound (rather than aglobal bass or treble effect), thepeaking equalizer is the instrumentof choice. In a sense, it is a morepowerful tool than the shelvingequalizer, because you can zero in onspecific frequencies and boost or cutin that range. When we say specificfrequencies; we are not saying that it


Confused About "Exciters"?Read the Facts.

Seems like a good thing always leads toimitators. Which is why there seems to be arash of so-called "brightness enhancers':"phase correctors" and "exciters:

The Aphex Aural Exciter® is a patented audioprocess that will recreate and restore missingharmonics. When added, they restore naturalbrightness, clarity and presence, and actuallyextend audio bandwidth. All without addingany appreciable power to the signal.

As a result, the Aural Exciter has become astandard tool in the recording, film, broadcastand sound reinforcement industries aroundthe world. It has been licensed for use in prod -

All Aphex products are designed and manufactured in the U.S.A.

®1989 Aphex Systems Ltd.Aphex and Aural Exciter are registered trademarks of Aphex Systems Ltd.

ucts sold by Yamaha, Numark, AKG, Proton,Gentner Engineering, MacKenzie Labs,and Vestax.

Other "brightness enhancers" only boostexisting high frequencies, pumping as muchas an additional 12dB, which can distort theamp or even blow your speakers ... in additionto sounding unnatural. In fact, you couldprobably achieve the same effect more flexiblyand economically by using any equalizer.

Don't be confused by hype. Listen to anydevice claiming to do what only an AphexAural Exciter does, then listen to the realthing. Your ears will hear the difference.

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100 500 1K 5K 10K 20KFrequency in Hertz

Figure 2. The familiar haystack -shaped curves associated withpeaking equalizers.

affects only one frequency, butrather a comparatively narrowrange of frequencies surroundingthe center frequency we have chosen.

In Figure 2, we see the familiarhaystack -shaped curves associatedwith peaking equalizers. (The widthof the haystack is fixed, and becomesa characteristic of the particularmanufacturer's sound.) This qualityis usually described by a specificationcalled "Q". "Q" is a measure of howfar to either side of the center

<

frequency the range of the equalizerextends, before diminishing to mini-mal effectiveness. "Q" is specified bya simple numbe4 usually between0.3 and 3.0: where the smaller thenumber; the larger the haystack.

Usually the "Q" (which is deter-mined by the manufacturer) is mod-erate-not too wide, not too narrow.Nonetheless, it is rather specific:being extremely active at the centerfrequency, but virtually ineffectiveas little as an octave away. While the"Q" is a given factor in peakingequalizers, the user can generallychoose from a continuous range ofcenter frequencies, enabling one toboost or cut almost anywhere in theaudible frequency range. This selec-tivity comes in real handy when it isnecessary to modify highly sensitivemid -range frequencies.

PARAMETRIC EQUALIZERSThese are the big guns. And like

most firearms, you should be ex-tremely careful when you operatethem or you could end up shootingsome big holes in your sound. Essen-tially, they are like peaking equaliz-ers with one added parameter: varia-

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ble "Q". In a sense, it gives you a cer-tain control over the design of theequalizer. It can be made veryfrequency specific (a high "Q"),which will allow you to boost or re-move a narrow band of sound withalmost surgical precision (See Fig-ure 3). You can also add an audible"spike" to the frequency spectrum ofany sound by boosting at the samehigh "Q". Additionally, you can selecta rather broad band of sound using alow "Q" setting, and of course, thereare lots of possibilities between thetwo extremes.

This is a power tool that can be ofgreat creative value. It can help cre-ate excitement when a track has be-come bland. It can also be used reme-dially, when there is a particularlyoffensive frequency that needs to beattenuated without materially af-fecting the bulk of the sound. (A goodexample might be removing a 60 Hzhum.) But as wonderful as it is, aparametric can be dangerous if notused cautiously. You can end up witha very uneven, peaky, or holeysound-if you use it to excess.

There are a few other miscel-laneous units which should be men-tioned briefly, under the rubric ofequalizers. Low pass filters do justwhat their name implies: they passall frequencies below a certain pre-defined point (say 16 k), whichsteeply rolls -off all highs above thatpoint. High pass filters do ananalogous service to the low end:they pass all frequencies above a cer-tain pre -defined point (say 45 Hz),which steeply rolls -off all lows belowthat point. If you stick a high passand a low pass filter together andplace their roll -off points closer to-gethe4 you get a band-pass filter,which allows a particular band ofaudio to pass through while at-tenuating everything above it and


below it. A device which tunes in anextremely narrow band of audio(much tighter than a parametric),and attenuates that band is called(not surprisingly) a notch -filter.

These miscellaneous tools ofequalization (notch -filters) oncecomprised a major section in theclassic electronic music studiosduring the 1960's and 70's, and arestill found in pro -audio facilities, butaren't seen much around today'selectronic cottages. Manufacturershave left them off of most synthesiz-ers feeling that today's sounds arefascinating enough without sophisti-cated filtering. Likewise, they hardlyever appear on reasonably -priced re-cording consoles. This is lamentable,since they are valuable and powerfultools and do not add noise to the mix,since they are passive devices. Nowthat we have a handle on the basictools of equalization, let's spend therest of this study discussing a benefi-cial mindset for learning the art ofequalization.

THE ART OF EQUALIZATIONConceptual EQ. Let me state out

front, that I am not against the"Neanderthal" method of equaliza-tion. You know, twist the knobs untilit sounds good. I use that methodsometimes myself, but only whenI've exhausted all rational means, orI'm so tired that I can't think concep-tually. But if I can think concep-tually; I will, because it saves me anawful lot of time and energy. Notthat I sit down with a calculator andtry to figure it all out on paper. It'sjust that a conceptual under-standing of the physics of sound,coupled with a little common sense,can put you immediately "in -the -ballpark" in determining whatfrequencies should be treated. Fromthere it's usually a simple matter offine tuning.

In a sense, it is a scientific ap-proach I am speaking of. Here's howto approach conceptual equaliza-tion: Based on whatever your knowl-edge of sound is (which will un-doubtedly grow over the years); youconstruct a hypothesis. For example:Let's say you want to put more"thok" into a kick drum. To do thisyou must accentuate a component ofsound that is already present. Thekick drum sound can be divided intoat least two parts: the resonancefrom the drum shell, which propa-gates large bass waves, and the

sound emanating from the slap ofthe beater against the skin. Onesound is low-the other is high. Thelow sound you need not bother with.It's the high sound you need tomanipulate. You try to identify inyour mind how high the high soundmight be. Is it high like a cymbal (10k or more)? No, of course not. It'smore like hands clapping or sticks

beating against each other. Sticks-they are made out of wood. Woodmight mean "boxiness" which is as-sociated with low mid -range (400 to800 Hz). But it's not like a woodencrate. It's more like two slats fromthat crate. A thinr_er piece of wood,therefore, a higher pitch. So it'sprobably an octave above the "boxi-ness of a crate" but well below the

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sizzle of a cymbal (maybe two oc-taves below).

If the cymbal is at 10 k, two octavesbelow would be half of 10, then halfagain which is 2.5 k, and an octaveabove 800 Hz is 1.6 k.

So the "thok" of the kick mightpossibly be found between 1.6 k and2.5 k.

Even if your hypothesis is assimple-minded and vague as thisone, it is at least a point of departure.You no longer need to be concernedwith highs or lows. Your goal is tosearch the lower mid -range, startingat 1.6 k.

Now test your hypothesis. At first,you might be wrong as often as youare right. But so what? Make

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another hypothesis based on the newevidence and test that one. Eachtime you make a hypothesis and testit, learning occurs-no matter if theresults are positive or negative.

With each experience the associa-tions in your mind grow into adatabase, which allows you to for-mulate your hypotheses on the basisof more intelligent information. Youwill no longer be in the realm of,"hmm, let's see what this does." In-stead, your inner voice will say,"hmm, let's see if this does what Ithink it will do." And that makes allthe difference when it comes tolearning the art of equalization.

Mastering the scientific approachto equalization: testing hypotheses,accumulating information fromyour experiments, etc., will lead,eventually, to a genuine artistic free-dom where results are achieved onthe basis of knowledge (rather thanchance), and are consistently repli-cable (not hit and miss)-all of whichis the essence of professionalism.

If you need proof that there is free-dom in discipline, I can only offer thisparable: A certain keyboard playerwas considered to be a creative mon-ster. Perhaps a monster in chainswould be a better description, for hismind took him on glorious musicalfantasies, but he could never per-form them properly. Why? Becausehe had never practiced basic scalesand arpeggios-his fingers could notmove fast enough to follow histhoughts.

One day though, he committedhimself to leave aside his composingfor a season, and practice scales andarpeggios daily. He did so for severalmonths. When he went back to com-posing again, he found that he waslooking at the keyboard as an en-tirely new instrument. At last, hewas able to actualize his thoughtsinto a beautiful performance. Thediscipline of practice had liberatedthis creative monster in chains.

And so it is with anyone who wouldlearn the craft of the recordingstudio-and most especially, the eso-teric art of equalization. Discipline,study, and experimentation are thesurest pathways to creative free-dom.

In the next issue of db, we will con-tinue our discourse on the art ofequalization by examining the over-tone series, formants, and a lot morepractical techniques. Stay tuned!


The ELAR Audio Library

The Books You Need To Be A Better Professional John Eargle'sHandbook of Sound SystemDesign has the answers to those needs youhave for accurate technical informationabout sound reinforcement. It containsevery thing from a small church to MadisonSquare Garden, from live sound for 60,000to canned sound for 600. Chapters: High -Frequency Speaker Systems, Mid -Fre-quency Speaker Systems, Low -FrequencySpeaker Systems, Dividing Networks, Cen-tral Loudspeaker Arrays, Distributed Sys-tems, Paging Systems, Microphones, -Allthis and more.

The New Recording Studio Handbook byJohn Woram and Alan P. Kefauver is foreveryone involved in recording. It is alreadyestablished as the "bible" for learning all thebasics of the recording studio operation.This includes the latest in the many kinds ofnoise reduction, analog recording, digitalrecording from multi -track to R-DAT, whatthey are and how you use SMPTE andMIDI time codes, signal -processing equip-ment, microphones and loudspeakers(monitors), and all about the new auto-mated consoles.

Ifyou are a professional in audio and usemicrophones in any aspect of your work, youneed John Eargle's definitive The Micro-phone Handbook. Among the topicscovered are: Using patterns effectively,directional characteristics, remote power-ing of capacitor microphones, sensitivity rat-ings and what they mean, proximity anddistance effects, multi -microphone inter-ference problems, stereo microphone tech-niques, speech and music reinforcement,studio microphone techniques, and somuch more.

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RONALD BENNETT

Education in SoundReinforcement

How many times have youbeen in a club, concert hall,or a live theater and beenfrustrated that the sound

wasn't all it could be? In the dayswhen a sound system was no morethat a pair of A -7's, a powered micmixer with rotary pots, a few RE -

15's and an SM-53; live sound sys-tems were simple to set up, and itwas easy to achieve the maximumsystem performance, such as it was.

Today howeve; even small clubsand churches have complex mixers,high-powered amplification, anddistributed multi -speaker systems.The sound engineer not only has tounderstand and command the gainstructure of the system; they alsoneed to be experts in lighting,drayage, rigging, power distribution,and have the understanding andskill to troubleshoot these complexand interactive systems. Clients nowexpect a sound company to come intoa place like the Los AngelesColiseum or the Mall in Washington,D.C. and provide intelligible sound

reinforcement for both spoken wordand music for an audience of150,000 people: including stagelighting, public address, intercom, alive broadcast feed, and a monitormix that satisfies everyone'sdemands-set up all in one day.Clearly, today's sound companies re-quire engineers with in-depth train-ing in a variety of disciplines: able toinstall, operate and troubleshoot sys-tems with hardware that they willencounter in the field.

HOW DO YOU LEARN THETRADE?

All to often, the only way sound en-gineers learn their trade is in the"School of Hard Knocks." This sys-tem has given us a few competentengineers, but all too often; thesound engineer knows only onemethod of operation, and has in-herited someone else's bad habits inaddition to their own. Some en-gineers have gotten the reputation ofbeing difficult to work with or stub-born. This is all too often just a shieldfor their lack of technical under -

Figure 1. Full Sail stage with the instructor discussing monitor settings.

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standing of today's complex sys-tems. Sound companies have takenpeople with a bit of raw talent and aninterest in audio (coupled with alittle of that "on -the -road" gypsyspirit) and educated them throughan apprenticeship program. In mostcases, this is a slow and less thansatisfactory way of training: yieldingpersonnel that know only one type ofsystem and hardware.

A SCHOOL FOR SOUNDREINFORCEMENT

There has been a lot of coverage ofthe educational opportunities inaudio in the trade press. There are anumber of fine schools offering edu-cation in recording and broadcastaudio, and one of the leading schoolsis Full Sail Recording in Orlando,Florida. They offer an intense pro-gram (up to 33 weeks -1,424 hoursof class time plus evening work-shops) in Recording Science forwhich they have received numerousawards. Full Sail has graduated over10,000 students and has an industryplacement record of 93 -percent,which speaks extremely well for theprogram. Unique to the Full Sail pro-gram is their Sound Reinforcementand Concert Lighting course.

I first visited the main campusfacility, a world -class facility de-signed by John Storyk and Full Sailfounder and C.E.O., Jon Phelps. It isone of the first VARMS concept com-plexes to be commissioned (theVARMS concept is the interconnec-tion of Video/Audio Recording andMixing Suites). I won't dwell on thefacility which serves as a commercialrecording studio/video post -produc-tion company and as the campus forthe school. Although both operationsshare the same building, each areoperated separately, and the opera-tion of the commercial unit keeps theFull Sail instructors in tune with thelatest developments in audio andvideo production.

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Figure 2. Michael MacDonald of Yamaha addresses the students.

THE STAFFFull Sail has a staff of almost 100

people, the majority of which are in-volved in the school. Dana Roun,Director of Education/Sound Rein-forcement at Full Sail RecordingSchool was my host for the visit. Hegave the background of the schooland the "nickel -tour" of the maincampus. Full Sail was founded in1978, and the Sound ReinforcementProgram (the focus of this visit)began in 1982. Mr. Roun, who has anextensive hands-on background insound reinforcement (with the likesof Boston, The Pat Travers Band,and Bon Jovi) has dedicated himselffull time to the Full Sail program. It

was interesting to note that the stu-dents sought his advice not only fortechnical assistance, but for per-sonal questions and guidance. Mr.Roun had started at Full Sail as aguest lecturer, a program which FullSail actively pursues (the day I wasthere, John Meyer of Meyer Soundand Michael MacDonald of Yamahawere on -site talking with some of thesound reinforcement students).

We left the main campus and wentacross town to the temporary loca-tion of the sound reinforcement pro-gram, a 50,000 square -foot buildingwhich had been an open floor -plansales office. With its high ceiling andhard roof and walls, Mr. MacDonald

Figure 3. The instuctor is "sabotaging" the mix console. Students mustthen discover the problem he introduced.

said, "This certainly is a real -worldenvironment: if they can teach thestudents to get a good sound in there,they will be prepared to handlesound anywhere."

As with all of the course, thisintroduction is conducted in

both the classroom andhands-on with the Full Sail

concert sound system.

THE COURSEThe Sound Reinforcement and

Concert Lighting course runs forfour weeks and can be taken as astand-alone course or as part of thefull program. Mr. Roun stated, "wewant to have an intense and concen-trated program; we have lab formatand classroom format. The lab for-mat has six to eight students withone instructor. We begin by introduc-ing a concept; then each student setsup a system and operates the systemfrom a non -operational start, i.e., theboard zero'ed out. In the third phase,the students are asked to leave andthe instructor introduces flaws intothe system and the student musttroubleshoot the system and explainhow they discovered the problems.This process is repeated for all of thelearning steps and processes in thecurriculum."

The Sound Reinforcement andConcert Lighting oDurse is brokeninto nine segments which begin withSound Reinforcement TechnicalSystems-where a study of the com-ponents that comprise a modernsound system are introduced. Thisincludes an introdt-ction to electron-ics, equalization, major system in-terfaces, signal processors, consolesignal flow, ampLfiers, and loud-speakers. As with all of the course,this introduction is conducted inboth the classroom and hands-onwith the Full Sail concert sound sys-tem.

Concert Lighting Technical Sys-tems covers the interfacing of light- 0,ing fixtures, dimmers, and lighting 17

consoles. This section of the course Efeatures a study of lighting basics forstage, theater, and instruments,dimmers' spots, rigging, trusses and -IRlifts, lighting design and production: =up to and including actually "cal- co

ling" the show.

The Engineering segment coversthe correct operation of the equip-ment for house engineering, monitorengineering and simulcast engineer-ing. This is done through actualhands-on engineering experienceand includes real-time troubleshoot-ing.

TOURING SOUND EDUCA-TION

Time is spent with the studentsdiscussing the real consideration ofthe "touring life." This is a veryhuman look at the people and jobsthat make a national tour a success.The purpose of the touring crew isexplained along with show produc-tion procedures and the ins and outs

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of "staying on top of it all." Tourstructure and income potential arestudied in detail with instructorswho have been there.

Clearly, a graduate of thisprogram is ready to handle

any system...

Each student designs a large scalesystem, both lighting and sound, andsubmits this as a mock bid. An over-view of the many different soundand lighting systems in use intoday's touring companies is given.In addition to all of the technicalskills discussed and taught, time isspent learning how to get a job in theindustry. What professions are avail-able and how to be psychologicallyprepared to get those jobs is pre-sented by industry personnel. In ad-dition, students learn the ins andouts of Remote Recording. Theylearn to interface the school's state-of-the-art remote unit with a livesound system and what the specificduties are for each member of theteam.

FULL SAILS' EQUIPMENTFor the first years of the course,

Full Sail rented systems from localsound companies and rented a venuefor the lab portion of the course. Thesuccess of the program demanded afull time system and Mr. Roun as-sembled a cutting -edge system basedaround Yamaha consoles and Meyerloudspeakers.

The system components representactual equipment that the studentswill encounter in the field. The sys-tem consists of a Yamaha PM3000console for the house, a YamahaPM2800 monitor mixing console,Meyer loudspeakers and amplifiersand Yamaha SPX1000 digital effectsunits, plus the normal complementof microphones. Full Sail also has aremote recording unit and a full con-cert lighting system, all of which areused in this study course.

Clearly, a graduate of this programis ready to handle any system, fixedor remote, and operate it to its fullestpotential. I heard a student mixingduring my visit, and especially con-sidering the building, it soundedclean and open. A tribute to the sys-tem, but even more, a tribute to theprogram. EI5


Wonder Plus (1DIR)Wonder Plus is a DOS shell. What's a DOS shell? It's a PC program that permits access to, andmanipulation of; all the files and programs on a hard disk in a computer.

When you have a 20 meg or morehard disk filled with assorted programsand perhaps thousands of files, you canuse all the help you can get to accessthem with ease.

Working with PC or MSDOS directlythrough its command structure is nopicnic with heavily -used hard disks.DOS shells help this access immenselyand make easy access to all files and pro-grams possible.

Here at the db Magazine office,where this sort of computer needabounds, we have been using Bour-baki's DOS shell for some time now.

Recently a completely revised and up-dated version of the 1DIR shell nowcalled Wonder Plus has been issued.We've been using it for a while and it re-ally permits access to programs and filesfar faster and easier than any DOS com-mand could.

Wonder Plus uses a user -createdmenu system that permits you to struc-ture the program to your specific needs.It can easily operate from the keyboardor with a mouse. Once trained to knowand access the programs on your disk,you only need to hit a function key oruse your mouse to go to the programname, hit the Enter key, and your pro-gram comes up on the screen. When youquit the program, Wonder Plus reap-pears on your screen (in color if youhave that capability) ready for its nextassignment.

While it is on the screen, you canscroll up or down to see files or sub -directories. You can switch to any otherdrive to see what is there and act uponthose files and programs. You can dis-play hidden files, and act on the attri-butes of those files to make them un-hidden, even erased, if you wish.

DOS shells use memory, of course,while they are active. But Wonder Pluscan be set to use conventional memoryor EMS memory. More important, it canbe set to remove itself completely whenyou invoke a program, only to reset it-self when you quit the program. So,while it is using memory to be on thescreen, when we activated MicrosoftWord to type this manuscript, WonderPlus was removed from memory leavingall that was available before for Word's(or any other program's) use.

One of the best reasons for using Won-der Plus is the ease in which you canmove from one program to another. Itliterally only takes a few mouse clicks.

It's a full -featured DOS shell in that italso permits creation or erasure of sub -directories and or files, formatting of

floppies, copying of disks and files fromany drive or directory to any drive or di-rectory; in short, anything that DOSpermits is done with ease and a fewmouse clicks or function -key combina-tions.

Do you have files or directories thatare restricted to others using the samesystem? Activate the Security Moduleand pa qgword-protect them.

We can't stress strongly enough thefact that the menu structure can becompletely custom configured to suit

any requirement. The manual and ref-erence card that came with the pro-gram are excellent, so even if you arenot excessively DOE wise, you will havelittle trouble creating a personalizedmenu structure that works best foryour needs.

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Outdoor SoundReinforcement forSymphony Orchestra

Classical music perform-ances comprise at leasthalf of the total live musicperformances in the

United States every year. The artistsrange from soloists to small en-sembles to full symphony orchestras.Quite often, these performances aregiven in concert halls designed andbuilt for the performance of acousticmusic. The best possible marriagebetween the architect's manipula-tion of acoustics and the artist'smastery of balance results in per-formances pleasing to the ear, ren-dered without amplification of anykind.

The past 25 years has seen an ex-plosion of innovation and technologyin the sound reinforcement field,embraced fully by popular musicforms. The dependence of today'spop musicians on sound reinforce-ment systems, coupled with the dra-matic incrassi. in the size of concertvenues, makes sound reinforcementan integral part of any popular musi-cal performance. Classical music,however, remained predominantlyacoustic, although various pop flirta-tions with classical music forms (e.g.Emerson, Lake and Palmer's ill-fated orchestra tour of the 70's) fore-shadowed a possible marriage be-tween classical music andstate-of-the-art sound reinforce-ment.

NEW THINKING FOROUTDOORS

The growing appetite of the Amer-ican public for outdoor classical per-formances necessitated new think-ing regarding the role of soundreinforcement systems in classicalmusic. For the first time, orchestraswere faced with an environmenthostile to natural enrichment andprojection of their sound. These per-

formances often took place on a tem-porary stage in a park or other openarea, without the luxury of even abandshell for projection. Crowd sizeexpanded logarithmically at theseshows; for the far reaches of theaudience to even partially hear theperformance, sound systems be-came necessary.

Due to familiarity, mic techniquefor these events mirrored classicalrecording technique: minimalmic'ing, featuring the use of omni-pattern mics, coincident pairs, anddistant area pickup were the rules ofthe day. As venue and crowd size con-tinued to grow, the need for bettercontrol of the sound soon dictated anew approach. RCI Sound Systems,the major mid -Atlantic symphonycontractor is one of several U.S.-based companies making importantinnovations in this brave new worldof symphonic sound reinforcement.RCI currently services both the Bal-timore and National Symphony Or-chestras.

THE INTERVIEWI spoke with RCI's most ex-

perienced symphony engineer, CraigJensen, about his company's ap-proach to the tricky problems posedby these large outdoor events.

db: RCI's Baltimore SymphonyOrchestra concerts over the past fewyears have been held at OregonRidge. Give us a "lay -of -the -land."

CJ: Oregon Ridge is located inHunt Valley, Maryland. It's a defunctski slope, a fairly small ski slope, withthe stage at the bottom of the hill. Soit forms a fairly large natural am-phitheater that could seat 50,000+.

db: The stage is placed so the or-chestra "plays" to the hill?

CJ: That's right. From the stage,looking at the hill, the incline of thefirst 100 yards or so is rather mod-

erate. Then it gets quite steep as theactual ski slope kicks in. The slope isbracketed on both sides by thicktrees that help contain the soundsomewhat, but can also cause aslight echo problem.

db: Has the echo ever posed a prob-lem for you or the orchestra?

CJ: Not really. It's only slightly no-ticeable from the stage, maybe alittle more so at the mix point, whichis about 100-125 feet out from thestage. When it's really obvious isduring loud passages: if you have apiece that ends on a loud note, youcan hear the slapback. That usuallygets a few chuckles out of theaudience.

db: How big is the stage area, andwhat does it look like?

CJ: The stage is an 80 -foot by 40-

foot wood slab, built on a small natu-ral mound that elevates it above thenear audience area. The stage is sur-rounded by wooden walls, located atthe sides and rear of the slab, so thatthe downstage side is the only openone. There are wooden baffles over-head, suspended about 20 -feet upfrom the floor (see Figure 1). Theseare hung from the roof, which is steelframe structure covered with aheavy duty blue -and -white tarp.That gives us a dependable water-proof covering for the stage.

db: Was the purpose of the wallsand overhead baffles to provide ashell for natural projection of thesound into the audience?

CJ: In a small sense that mighthave been part of the reasoning, butthe main thing was really monitor-ing. When the orchestra is in theirconcert hall environment, the farcorners of each section can hear eachother. The basses can hear the firstviolins, and vice versa, so they canplay together. That's the most im-portant thing for an orchestra stage,

immt z11111M

L'SO

Figure 1. A detail of the Oregon Ridge Orchestra Shell.

and it's one of the reasons why con-cert halls are as live as they are.

db: And outside, which is essen-tially anechoic, you don't have anyliveness.

CJ: Right. That creates the needfor a shell like the one at OregonRidge. We also do the National Sym-phony Orchestra several times a

year on the West Lawn of the Capitolin Washington, D.C. That stage is es-sentially open, it's covered only by alarge tent. You can walk up therewhen the orchestra is playing andnotice the difference right away. It'sa far less desirable situation for themusicians, but since it's only donethree times a year; they basicallywing it.

Figure 2. One ofthe typical speakerstacks used atOregon Ridge.

db: You mentioned that you'vedone jazz and pop shows at theOregon Ridge site using the shell.How did that work out?

CJ: It was too live; very reminis-cent of the problems you have whenyou do pop shows inside a concerthall. You can't get the good tightmix that you'd like. The jazz showwas great-it was low-keyedenough to work. But don't do a rockband there! (both laugh)

db: What do you use for a sym-phony speaker system?

CJ: On each si le, I use 4 RCI 490cabinets, sometimes called "superboxes," and 2 RCI 240 cabinets,sometimes called "long throws."We erect a 50 -foot scaffold tower, a6 -foot by 4 -foot section, I believe, oneach side of the stage and fly thecabinets inside of these. The four

super boxes are hung together in acolumn, with two long throws up ontop (see Figure 2).

db: Where were these towersplaced with respect to the stage;were you in front .A or even with it?

CJ: The stage is built on unevenland, so we weren't as flexible aswe'd have liked on the scaffold place-ment. We were able to buy a bit ofroom downstage, so the speakerswere a good five -to -six feet in front ofthe downstage lip. No mics wereeven close to the downstage edge, sowe had a good start on gain -before -feedback (see Figure 3).

OREGON RIDGE AUDIOTHROWS

db: You've got a very long area tocover at Oregon Ridge. How do youinsure adequate level at the rearwithout toasting the people in front?

CJ: One advantage I have is theslope. You can walk back from thestage as far as 200 yards and still bein the audience area, yet the line -of -sight distance is less. With the sys-tem flown, you still have speakers inyour face up on the hill. The longthrows do an excellent job of cover-ing the upper slope area; in fact, Iusually run these on a separatematrix output so I can push themmore than the lower boxes. This fillsout the farthest audience area, yetthe cabinets are up high enough thatI don't overpower the nearfield.

db: That's a great idea!

Figure 3. Overall view of the Shell and stacks, Oregon Ridge.

CJ: I'll often use a three -tiered sys-tem. I run the bottom pair and toppair of super boxes on separatedmatrix outputs as well.

As the speakers go highei I can runthem hotter, all of which helps mydistance coverage. I should alsomention that the first twenty feet ofimmediate downstage lawn area is

Nco

roped off, so no one can get any closerthan that to the stage or either stack.

db: Do you run the system instereo?

CJ: I never run stereo; instead ofleft -right on my graphics, I run up -down. The lower set of cabinets re-quire a bit more EQ than the upperones due to stage proximity. The

Figure 4. A nomni Iso-Max isshown positionedover typani.

upper cabinets are forty feet in theair; I really don't have to worrymuch about feedback problemsthere. Plus, the audience is reallyspread out, so stereo would bedetrimental to most people. Bettercontrol up -down means I can bettercover the rear areas, more benefi-cial to the guy two -hundred yardsaway who just paid $40.00 andbrought the whole family out for aconcert/picnic.

db: Perhaps delay stacks could beused to fill in rear areas. How doyou feel about them?

CJ: We use them, and in mostcases I would favor them. However,it becomes a bottom -line issue: withmore labor, time, and gear involvedit becomes a trade-off betweenwhat the orchestra really needs tocover the audience and cost. At theWest Lawn location for the NSO weuse them, and they're very effec-

tive. The site is fairly flat, and theaudience for those concerts can beupwards of 150,000, so sheer size ne-cessitates delays.

TOTAL COVERAGEdb: What do you figure your total

area of coverage at Oregon Ridge is?

CJ: It's probably in the neighbor-hood of 150,000 square yards, whichis a huge area. And we can have hugecrowds. Our coverage is helpedsomewhat by the containment pro-vided by the trees on either side andthe hill itself. Delay stacks weredeemed superfluous due to cost andthese physical advantages.

db: You're dealing with acousticmusic, dependent for years on theacoustic environment of concerthalls for projection towards theaudience. Now you find yourself out-side, where natural acoustics can nolonger handle the coverage require-ments, let alone balance and tonalconsiderations. What do you feel arethe most important elements in re-inforcing this music?

CJ: Outdoors, with 10,000+people, the subtleties of what the or-chestra is trying to do will not comeacross like it will in the concert hall.You aren't going to hear the secondoboe playing a harmony with thefirst oboe, in a quiet passage, fromthe back of the audience area. It'snecessary to exaggerate these typesof things level -wise so the audiencecan hear them.

Figure 5. Microphones over the string section.

db: Traditional mic technique forclassical reinforcement dictates theuse of omni-directional patterns orcoincident pairs for area pickup.What's your view on this?

CJ: To get the necessary gain tocover subtleties two -hundred yardsaway-it's just not going to happenwith distant mic'ing. You need bettercontrol, and all the gain you can get.We went to using as many as fortymics on a symphony orchestra. Wefound that by following scores andgetting cues from people who knewthe particular pieces well; we couldbring up any section of the orchestravery easily and obviously if need be.

db: The idea of placing one's musicin the hands of a third party was anidea that terrified most musicians atfirst, I suppose. Nowadays, manypop groups routinely have an en-gineer recreate their sound forthem-it's no big deal. But it is verynew ground for classical music: yourmulti-mic technique places more re-sponsibility for orchestral balance onthe engineer than ever before. Doyou work with the conductor inbalancing the orchestra to theirdesired ends?

GETTING STRINGS LOUDENOUGH

CJ: Before I talk about conductor -engineer trust, let me mention ourmost basic problem outdoors: get-ting the strings loud enough. Thestrings are probably the one instru-ment most people relate to a sym-phony orchestra. They are the bulkof the orchestra; they play most of

the moving melody lines, yet are thequietest instruments. Just abouteverything else projects better out-doors. Some people in pop musicstart with the drums: they feel if theyget the drums sounding good, theyhave a basis for a good mix going. Inorchestra mixing, it's getting thosestrings loud enough; trying to get theSPL needed without letting them gettoo shrilly, working to maintain anice warm sound.

db: Some purists might argue thata simple coincident pair over thestrings could do a better job of pre-serving inter -section tonality andbalance.

CJ: I still don't think you can beatthe gain we get from a mic on everytwo to four players. On cellos, wemight go to one mic on very two play-ers. The concertmaster might get his(or her) own mic for solo pieces.That's another distinct advantage tomulti-mic'ing: we can spotlight theconcertmaster for a solo passage,something area mic'ing wouldn'tallow.

db: Creating voicing through in-strument level changes is a given formany pop engineers. Is this some-thing you feel is important for classi-cal multi-mic mixing technique?

CJ: I feel the symphony orchestradoes a better job than any otheridiom of music in controlling dynam-ics-playing in sections with eachother. That's part of the conductor'sjob, to control those sectionalbalances. The orchestra is stillmixing itself: I'm not moving fadersa lot during performances. And just

because I have all these micsdoesn't mean I have to use all ofthem. I'm there to improve projec-tion, not balance. Sometimes sym-phony personnel might come upand tell me they feel the stringsaren't quite loud enough during acertain passage. I can highlight acertain section more easily than Icould with coincident pairs scat-tered about. And multi-mic'ing isfar superior for pieces that havelots of solos.

db: Can you give us an exampleof a heavy solo pie 3e?

CJ: Ravel's Bolero is a perfect ex-ample: a very popular piece, whichwas played twice last year. It's avery building piece, with cascadingsolos during the entire piece. Forthat, I had a cue sheet of every solocoming up, so I could give it justthat little bit extra and get it heard.It goes back to the idea of exagger-

ating for an outdoor show.db: Did the condt. ctor ask you to do

that?CJ: I have no problem taking

direction. But it's funny: for themost part, they've :eft me alone. I'mletting the symphony mix itself; Ijust exaggerate the parts so peoplecan heat I think the conductors,trained as they are, can hear theamplification I'm doing and approveof the job. If I hear anything, it's usu-ally from the symphony administra-tive people, like the artistic director,who know symphony sound verywell-they gave me the cue sheet.They're happy because response tothe outdoor shows has been over-whelmingly positive.

db: Do you have a background inclassical music?

CJ: I was a music. major in college,and played trombone in various highschool and college symphony or-chestras. I've studied classical musica lot, and enjoy listening to it in myspare time.

MULIPLE MICSdb: Aside from the artistic con-

siderations, there are technical con-siderations to using multiple micro-phones. The potential for feedbackincreases as the number of open micsincrease, as does the problem of un-wanted instrumental bleed. How doyou counter those problems?

CJ: I could have a single coinci-dent pair over the strings, andduring an ensemble fortissimo pas-sage, the brass is going to be louder in

mics back in the brass, which Ithought would easily be enough, andI really missed out on some of thetrumpet harmonies. I should havehad two mks just for the trumpets!It's another point about areamic'ing: I got a decent blend, but Ijust couldn't get the SPL I needed topull those trumpet harmonies out. Ifit's a Fourth of July show, you've got50,000 people, and Bugler's Holidayis on the program-well, people two-

hundred yards away have to hearthat part.

db: How loud are your clientsasking you to run the system: is thePA basically coasting, or are you get-ting into real level?

CJ: I'm not getting into real level,and that goes back to the feedbackquestion you mentioned. A lot ofpeople think that forty mks puts youinto a feedback nightmare as op-posed to a smaller number of coinci-dent pairs or whatever. I don't pushthe system that much; the PA isthere primarily to pinpoint sectionsbetter. I don't run any particularmks that loud; the ones I push themost are the string mics. String levelis always my major concern. I haveanother thing to consider with re-spect to string sound: no string

player ever brings their best instru-ment outside in 95 -degree weather.Instead of the $10,000 violin, theybring out the $1,000 violin that theyused in high school or college.

db: Considering summer weatherin the Washington area, especiallythe humidity, I can't blame them.

CJ: The top instruments don'tcost more because they're older, nec-essarily, but because they sound bet-ter. The cheaper ones just aren't asnice; they're not as rich, and can'tgive a tone like the good instrument.They can start to sound screechywhen I get them loud enough; often Ifind I have to cut the 1.6-2 kHz areaquite a bit to compensate.

SPL OUTPUTdb: How many dB -SPL are you

pushing at the mix point?CJ: The dynamics of some of these

pieces are as wide as you could im-agine: there could be a flute solo forten seconds followed by total en-semble playing, fortissimo. At theloudest, we're pushing 100 dB-SPLat the mix. On the other hand, you'vegot soft string phrases that you can'tget loud enough. To the people sit-ting two -hundred yards back, it'svirtual silence unless you have an ex-

Figure 6. A closeup view of the'cello mic'ing.

tremely quiet audience. For the mostpart, you've got an ambient noiselevel of 55 dB-SPL from wine bottlesopening, children playing and cry-ing, and adults chatting. It's a festi-val atmosphere, not a serious classi-cal crowd. Fortunately, the programsare pops -oriented, so I don't have alot of the pieces that are all over theplace dynamically. We probably aver-age between 85 and 90 dB-SPL.

db: Your normal console for thesejobs is a Yamaha PM -3000 40 -chan-nel desk. Do you use any outboard ef-fects, such as digital reverb?

REVERBCJ: I definitely reverb the or-

chestra, especially the strings. Re-

verb is part of the sound of the or-chestra in a concert hall, and peopleexpect to hear it. There isn't any re -verb outdoors, of course, so we recre-ate it digitally. It makes all the differ-ence in the world-I couldn't livewithout it.

db: What sort of reverb units doyou use, and how do you programthem?

CJ: I've been using the small hallprogram on a REV -7, which mightsurprise a lot of people. It seems towork better than the large hall pro-gram, which can sound a little unre-alistic outdoors. I use this on eighty -

percent of the string mics, whichgives me a nice overall reverb thanksto bleed. I'll use a second reverb, likean SPX -90, to spot reverb those colorsolo passages here and there. I knowthese pieces; if I don't know them, Ican get and read a score. I wait untilthat spot comes up, and then add justa touch of reverb. It gives that nice,concert hall sound.

db: Do you return the reverb flat,or do you EQ the return with a cer-tain acoustic in mind?

CJ: The reverb can create a feed-back problem in the low mids andlows. I'll dial some of that out: an 80-100 Hz high pass filter on the lowend, maybe take out a bit of 315 Hzand go from there. I don't take outtoo much of this stuff because then itcan start to sound thin. If I bring thereverb back on an input channel, I'llEQ it there. If I have to use an effectsreturn I'll use the reverb's on -boardEQ, if it has one, with the EQ on thereturn to achieve the desired effect.

db: I've used RCI's system for popshows, and as I recall you have incor-porated system limiting in your

Violas8-10 chairs Vocal

micAnnouncer

mic

AUDIENCE

Conductorspodium

Oboes4 chairs

Bassoons4 chairs

flutes4 chairs

Clarinets4 chairs

French horns5-6 chairs

1st violins12 chairs

(includes concertmaster andassistant corcertmaster)

Miscellaneouspercussion

XylophoneIII lif IliIII

inns

PERCUSSION

4 tympanis

0000

Diagram 1.The Baltimore Symphony Orchestra stage layout.

Strings:5 First Violins: 1

3 Second Violins: 33 Violas: 33 Cellos: 33 Double Basses: 3

Woodwinds:2 Oboes:2 Flutes:2 Bassoons:2 Clarinets:

Brass:2 French Horns:409's1 Trumpet:1 Trombone:1 Tuba:

Percussion:2 Timpani:1 Xylophone:1 Misc. Perc.:

Miscellaneous:2 Grand Pianos:1 Harp:1 Celesta:1 Vocal:1 Announce:

AKG 460, 4 Sennheiser ME -40'sSennheiser ME -40'sAKG 451'sAKG 451'sSennheiser 421's

2 AKG 451's2 AKG 460's2 AKG 451's2 Electro-Voice ND -408's

Diagram 2. Instru-ments and respec-tive microphonesused for the Balti-more SymphonyOrchestra perfor-mances.

2 Crown PCC-160's or 2 Sennheiser

Electro-Voice ND -408's Y -d2 Sennheiser 421's Y -d1 Electro-Voice RE -20

2 Countryman Isomax1 Countryman Isomax1 Countryman Isomax

2 AKG 460's or 1 AKG 460, 1 C -Tape1 Countryman Isomax1 AKG 4511 Shure SM-87's1 Shure SM-57's

1st violins4 chairs

Ge\es2;cyo\x

those mics than the strings-andwe're talking about a brass sectionthat is upstage center or left quite adistance away. There's really noth-ing you can do about that. Havingseveral mics closer to the strings de-finitely gives me better control than Imight get with distant mica.

db: That situation requires you tobe sensitive enough to use that bleedto your advantage, and to knowwhen to turn mics off.

CJ: Well, with forty mics on the or-chestra, you can bet that when thebrass is blaring away in the big partof the piece I'm not using much ofthe brass mics! Sometimes I wishthey'd play soften but they're used toa concert hall and no mics: theyknow it's supposed to be loud.

db: Have you ever considered cut-ting back on the brass mics?

CJ: There have been times, whereI only had a 32 -channel console in-stead of the 40 I'm used to, that Ididn't fully mic the brass to savechannels. I figured I'd have no prob-lem picking them up, and I ended upkicking myself. There was a piece wewere doing, Bugler's Holiday I thinkit was, where there is this importantensemble trumpet section. I put two

Figure 7. Double bass instrument mic'ing.

drive rack. Is that something youeven need for a job like this?

CJ: I suppose some God -awfulthing could happen that might senda dangerous spike through the sys-tem, like a mic falling off a stand.But at the level I run things, damag-ing the system is a very minute possi-bility. I take the purist attitude andpatch around the limiters. I reallydon't need another device in theaudio chain; I keep it as simple aspossible.

MULTI-MIC TECHNIQUE FORSYMPHONY ORCHESTRA

I asked Craig to give us a real basicmic'ing for orchestra, as the specificdemands of particular pieces willdictate changes in the actual num-bers and locations of microphones.The corresponding photographs area combination of both the OregonRidge and West Lawn sites (see alsodiagrams of the BSO's stage layoutand channel assignment and miclist).

db: What design of mic do you pre-fer?

CJ: I use as many condensers as Ican get, especially on strings. Theyhave the clean, full sound I'm look-ing for, and they also give me the bestavailable gain at the mic. While re-sponse does vary between brands, Ifind they're flatter than dynamicsfor the most part.

db: Since you're outside, you mustuse a lot of windscreens.

CJ: I've got them all over theplace, and definitely on every con-denser. Most of these tend to be

downstage on the strings, where anywind will get picked up. The ones onthe woodwinds are more upstage,and are protected by the shell some-what, but if I have enough wind-screens I use them back there too.

WIND NOISEdb: What sort of console EQ or fil-

tering do you use to minimize windnoise?

CJ: Any of the sub -harmonic stuffis not going to help in an outdoor sit-uation. I prefer to keep the mica flat:I don't use the roll -off switches onmks like the Sennheiser 421, ME -

40, or the AKG 451 and 460. If I'vegot a board that has a versatile, flex-ible EQ with adjustable high-pass fil-ter, I'd much rather do it at theboard. On strings, I'd use a 40 Hzcut. I'd use that on most mica in theorchestra except double basses andtubas. To be honest, I could probablydo it there too, and no one would re-ally notice. Fortunately, I don't oftenhave a bad wind problem. The shelland top offer some protection, butconcert timing helps even more. Inthe summertime, at least on the Eastcoast, the winds tend to die down atsunset, which is around the time westart.

USING OMNISdb: I've been involved with out-

door symphony performances in myhome town of Detroit. Because Iused a lot fewer mica than you, weemployed a mixture of cardioid andomni patterns. You have a real fortymica up-do you use omnis at all?

CJ: I am using a few omnis, butin one case, the pattern type is re-ally secondary. I'm using aCountryman Isomax inside of aharp. It gives a gorgeous flatsound-I don't really have to domuch of anything with channel EQ.That's really why I'm using thatmic there, not because it's an omni.I also tape them to the tip of astraight mic stand or boom andlean it into a percussion table, xylo-phone, or timpani (see Figure 4).That also gives a very nice sound,and because there is so muchacoustic SPL hitting these mks, Idon't have to turn them up as muchand risk picking up any nearbybleed.

db: Where are these instrumentslocated?

CJ: They are far, far upstage,where I get great gain -before -feed-back. The harp mic is inside, where

I get great isolation, and the timpaniare so far upstage there really isn'tanything nearby to bleed into them.It's always the downstage mica thatare more susceptible to bleed. I actu-ally do benefit from the omni patternon the timpani, because I can use onefor every two drums and get realeven pickup between them.

db: What do you do if you havemore than one harp?

CJ: Harps have a very distinctsound. Sometimes an oboe cansound very similar to a clarinet, aviola similar to a violin, but there isnothing at all that can sound like aharp in an orchestra. It's what Iwould call an accent instrument.When it's played, it needs to beheard: it needs to stick out a little bit.I could area mic two harps, but I'dnever get it loud enough to do that.With the mic inside, you get plenty ofharp-certainly you'd never evenget near a feedback problem. So I'duse one Isomax inside each harp.

MICS ON THE FIRST VIOLINSdb: The first violin section is the

orchestra's largest. You mentioned aconcertmaster special earlier, that isone of the first violins. How exactlydo you handle this section?

CJ: The concertmaster and as-sistant concertmaster are the twopremier violinists in the orchestra. Iuse one mic, split between them, forthat reason, and also because if thereare spot violin solos during a piece,they will play them. I use an AKG460 cardioid condense4 and try to

get it in as close as I can, with somecompromise for bow clearance. Iplace the stand on their upstage side,with the mic angled away from theupstage side and towards theaudience. That helps keep most ofthe bleed, which is coming from up-stage, off -axis.

db: What about the rest of the firstviolin section?

CJ: I use Sennheiser ME -40's,which are cardioid condensers. Theydon't quite have the same quality ofhigh -end that the 460's do, and I likethat, because I have a problem withtoo much high -end on the violins.These are two -to -three feet away,placed and angled the same as theconcertmaster's special. I try and dothat with every string mic I can.Every group of four players gets onemic (see Figure 5).

THE SECOND VIOLINSdb: Now, we have the second vi-

olins. Do you use the same type ofmic here as well?

CJ: I do use the ME -40 here: be-cause it's the same instrument, I liketo use the same type of mic. Theparts are not the same, however. Sec-ond violinists aren't seconds becausethey aren't as good players; seconds

play a completely different harmonythan firsts, and it's equally impor-tant that they be heard. The mics areplaced and slanted similar to theother violin mics, and every group offour gets one mic. I do cheat on thefirst group of four; as the first twoseconds are the best players; I favorthem slightly.

OTHER STRINGSdb: There are a smaller number of

violas; what do you do there?CJ: Usually, there are ten chairs,

so I go 2-4-4 with the three violamics. The group of two includes theprincipal, so I have solos covered. Iuse AKG 451 cardioid condensershere: since the viola is a lower regis-tered instrument than the violin, Ifind I don't have as many high -endproblems with them.

db: What about the cellos anddouble haQ-ses7

CJ: On the cellos, I use 451's. Ioriginally started with Sennheiser421's, which are dynamic cardioids,but I really fell in love with thecleaner, livelier sound I got from thecondensers (see Figure 6). For thedouble basses, I do use 421's (see Fig-ure 7). I'll always use the first mic ofeach section on the first two players,

Figure 8. Flutemics are shown.

favoring the principal. The othermks basically split pairs of players,but that can depend on how many wehave that day. I used to damp themks on their music stands, but I'veevolved to floor stands with shortbooms. I try to get them as close as Ican without getting in the way,around two -to -three feet from theinstruments.

THE WOODWINDSdb: We now come to the woodwind

section, which has a diversity of in-struments, including sectional di-versity. Let's start with the flutes.

CJ: The standard setup is threeflutes and one piccolo. The othersdouble on piccolo when the needariccs in Stars and Stripes Forever,they all play piccolo. Piccolo is an in-strument that doesn't require a mictoo close in order to pick up fine! Thetwo mks split the four players;throughout the woodwind section, Ifavor the first chair; who is theprincipal and the best player on thatinstrument. I find I can get the en-semble sound when I need it-theunison parts are not compromised.Yet, any solo spots will be played bythe principal, so I still need to be ableto highlight that. Occasionally, Imight have a bass flute. If I can't givethat a separate mic, I will at leastcheat a mic towards it. I mic thesefrom overhead, like the violins, usinga pair of 460's or 451's (see Figure 8).

db: What's the oboe situation?CJ: It's sort of similar to flutes.

You have four players, with threeoboes and one English horn. TheEnglish horn is similar to an oboe, alittle longer, with a little ball shapeon the end. I use a pair of 451's, split-ting the pairs and favoring theprincipal and English horn. Place-ment is similar to the basRPs. I use afloor stand with short boom, comingup from the floor about three inchesaway. The mic is aimed at the centerof the instrument, halfway up thetube. On these instruments, soundcomes out the holes in the body aswell as the bell. By mic'ing halfwayup, I get a better balance betweenhigh and low notes. I use the sametechnique for clarinets and bassoonstoo, by the way.

db: What surprises do the clarinetshold?

CJ: There are four players thatcan play three different instru-ments. Typically; it's three B -flatclarinets and a bass clarinet. Some-

Figure 9. The Baltimore Symphony Orchestra in performance at Ore-gon Ridge.

times you have an E -flat clarinetplaye4 or several B -flat clarinetplayers double on E -flat clarinet.The E -flat is a higher register,shorter instrument that goes sub-stantially higher. It can soundsharper, more brilliant than the B -flat, and it cuts really well. I usuallydon't worry about a separate E -flatmic unless there is an extended solo.We use two EV 408's, which are theirtop -of -the -line, swivel -mounted,neodymium, cardioid dynamics. I'mvery pleased with these mics onclarinet; it's the closest thing to acondenser you can find in a dynamic.I split pairs of players, favoring theprincipal and bass clarinet, which isa lower registered instrument. If Iknow about a bass clarinet solo, Iwould definitely give it a dedicatedmic and change somewhere else.

db: Finally, we have the bassoons.CJ: Again, we have four players,

with three bassoons and one contra-bassoon. I use a pair of 451's, split-ting the pairs. I favor the principaland really favor the contrabassoon.The contra is an extremely low regis-ter instrument, and doesn't get veryloud.

THE BRASSdb: We now enter the brass sec-

tion. You've listed two mics for sixFrench horns. How do you managethat?

CJ: What I really like to do is usetwo Crown PCC-160's, the cardioidPZM mics, and place them on foam,on the floor, behind the section.Strangely enough, I've had argu-

ments with players telling me to micthem from the front. I'm convincedthat the majority of the qualitysound comes from the bell, as it doeson all brass instruments. It's not likea woodwind, where there are allthese holes for sound to come out.And as the instrument is played, thebell points to the rea4 away from theaudience. My real problem is space:the French horns are usually backedright up against the percussion sec-tion. The PCC-160's are useless un-less you can buy yourself some roomin the back. I like to back the mics offa bit to get a better blend, but that'salways a logistical problem with theFrench horns. If I've got to go close, Iuse a pair of Sennheiser 409's, whichare dynamic cardioids. Again, I favorthe principal, split the second pair,and forget the third pair.

db: For trumpets, your layoutshows a pair of mica y -d. We'll addthe caveat that you don't have thechannels, as your layouts changefrom concert to concert. What do youuse?

CJ: I've been using EV 408's, likeon the clarinets. But I could reallyuse SM-58's if I had to. There's noquestion that the trumpets are theloudest thing on stage, so I only usethese mics for sections that have tobe heard, like Bugler's Holiday ormarches. I use two mics, splittingeach pair of trumpets and favoringthe principal. Usually, the trumpetsare too loud with their mics off.

db: How about the rest of thebrass?

CJ: For trombones, I use a pair ofSennheiser 421's y -d, splitting thetwo pairs and favoring the princi-pal. My tuba mic is an EV RE -20, alarge -diaphragm, dynamic micthat's great for low -end instru-ments. I suspend it over the bell,about a foot -or -two away. The RE -20 is a heavy mic, so we use thelarge Atlas studio boom stand withthe twenty-five pound triangularbase.

PERCUSSIONdb: You touched on percussion

earlier. The two timpani mics areIsomax elements, taped to a standand positioned one per pair ofdrums. You also have two extraIsomax for extraneous percussion.What gives there?

CJ: It depends on the program.For The Star Spangled Banner, Ilike to have a snare drum mic. All

it's for is the opening of the piece, butit's so crucial that you have to have it.I might never use it again, but I needit for that opening. Many Gershwinpieces have heavy xylophone parts,so I need a mic for it. With percus-sion, you're talking about instru-ments that don't have sound comingout of a bell, hole, or whatever. Youcan't just point a mic in one directionand know you've got it. That's whereI like the omni pattern of the Isomax.

db: You've got a better margin oferror.

CJ: Exactly. On a xylophone,which is about five -feet long, I canput one in the middle and get an evenbalance between notes. Most ex-traneous percussion I can get withone omni, because the parts areplayed loudly. That's the beauty oforchestras: they take care of them-selves. The conductor tells themwhat has to stand out in a certainpassage, and it does stand out.

PIANOdb: You have two piano channels:

listed are a C -tape and a regular mic.Is this your standard method?

CJ: My favorite method is to use apair of AKG 460 condensers in anear -coincident pair. I place these inthe middle where the strings cross,making sure I don't put them tooclose to the hammers. If the lid has tobe closed, I just tape them to the lid;otherwise, I point them inside withboom stands. If I don't have a sound -check, I'm more comfortable with a

C -tape and a 460. I know I can getthat loud enough on the fly.

db: The only instrument left is thecelesta.

CJ: I think of the celesta as a verypercussive piano. It looks somethinglike a small upright piano, althoughthere's no acoustic soundboard. It'smore like hammers hitting plates. Iuse an AKG 451, on a floor standwith a short boom, and point the micat the back center of the instrument.

VOCAL MICSdb: Finally, you have two vocal

mics, one of which is a dedicated an-nounce. What's your preferredchoice?

CJ: That depends on the vocalist,but I'm fond of the Shure SM-87, acardioid, condenser vocal mic. Ofcourse, depending on the program,we might have to use several vocalmics. I had to do that with CarolCharming: we needed four vocalmics, all at different locations onstage. I used SM-58's for that one,because it was a handheld situation.I use an SM-57, with a windscreen,for my announce mic because itlooks neater.

db: Is the announce positionednear the podium?

CJ: It depends on the conductor:some just swing a boom over to thepodium and talk. Others want tostep down and move; for them, I putit on a straight stand a few feet awayfrom the podium (see Figure 9).

db: You mentioned that you mightoccasionally use D.I. boxes. Whatsort of stuff might that be?

CJ: Most of our outdoor concertstend to be pops programs; anyonewho has gone to a symphony morethan twice knows what that is. Youare going to hear Gershwin, somemarches, some movie themes, thatsort of thing. With these types of pro-grams, you are going to find trapsets, electric basses, sometimes elec-tric keyboard or synthesizer of somekind. Occasionally, you even haveelectric guitar, although when thathappens I mic the amp, just like youwould in rock-and-roll. The electricbass and electric keys I would takeD.I., though. One show, we used asynthesizer program for digital can-nons on the 1812 Overture, althoughthey blew that off this year. I don'tknow why; it's an effective way ofdoing it if you've got the right sam-pling.

FOURTH OF JULY AND ITSIMPLICATIONS

db: You do three concerts with theNational Symphony Orchestra, allat the West Lawn of the Capitolbuilding. I understand that theFourth of July concert theredemands a larger commitment thanthe Memorial and Labor Day con-certs.

CJ: That's putting it mildly! Theminimum audience size is 100,000and it could go as high as 300,000.The scope of the event is just mindboggling. This year, we even did anational TV simulcast over the PBSnetwork, through our local affiliateWETA.

db: With that many people, youmust add the delay stacks you men-tioned earlier.

CJ: We add the delay stacks and abackfill as well. For this one day,people sit behind the orchestra, onthe Mall. We put up additional scaf-folding and hang four additional 490cabinets on each side of the rearstagearea, pointing toward the Washing-ton Monument. The main area delaystacks are three 390 cabinets: theseare much smaller three-way cabi-nets, typically used for smaller PAjobs or as part of a monitor system.

db: What sort of spacing did youuse between the stage and the delaystacks?

CJ: It's about two -hundred feet,and since the audience tends to fanout, we put them out wider than themain stacks. We still used the longthrows, though, to help push thesound out there. Each delay stackhad it's own AC generator, and audiowas fed from the house mix locationvia a wireless link, so we didn't haveto run any wires through the crowd.

MIC CHANGES FORBROADCAST

db: Did your mic'ing change due tothe simulcast requirements?

CJ: It certainly did. At the sugges-tion of the TV engineer, we put aCountryman on every violin. We vel-cro'ed an Isomax to the bridge ofeach individual instrument.

db: Now that's the ultimate inmulti -channel symphony mic'ing.How many channels did that turnout to be?

CJ: It was pushing ninety. Wedidn't actually take all those mics;we were fed two different string sub -mixes from the recording truck, anddid our own thing on the rest of the

orchestra. The mks we shareddirectly were split via a trans-formered mult box. If you want totalk about gain -before -feedback,that was the ultimate.

Since the Countryman is a veryflat mic, you get jtst what the playergives, which is nice. No problem get-ting the strings loud enough here!But we did start to get into all sorts ofextraneous noise: when the instru-ment was set down, when someoneaccidentally hit their bow against astring. Plus, a lot c f players found theidea of a mic attached to their instru-ment a bit disconcerting-littleaside comments to each other duringthe pieces were picked up.

db: The whole idea of it has pro-found implications with respect tobalance.

CJ: I usually don't have the luxuryof a mic on every player, and I'm notsure I'd want to. I think of our multi-mic technique as close area mic'ing,rather than close inic'ing. By mic'inggroups of foul I have a mic withinfive -feet of any player. I still get anatural, blended sound-somethingI think would be hard to get with amic on every player. Yet, I still get thegain I need, something I wouldn't getwith distant omnis or coincidentpairs. I also like the idea of a little airbetween the mic and a stringed in-strument.

db: Even in the studio, I don'tthink true close-mic'ing has everbeen tried, although I could bewrong. Given the time constraintslive, it would be difficult to do. Theconductor would have to come outand mix, just to get the voicing cor-rect.

CJ: I think that if the conductorsknew how much power engineershad over the sound, they'd be veryconcerned. That certainly isn't thecage with four coincidental pairs, butwith multiple mic'ing an engineercan drastically change the overallsound of an orchestra, for better orfor worse. I've given the option ofmic'ing every stringed instrument tothe BSO, and they rejected the idea,believing that it would be very diffi-cult to get that nice blend.

db: The day may come when con-ductors sit at the console and actu-ally mix the performance like popengineers, voicing the sections asthey see fit. You could emphasizestrong players, de-emphasize weakones, change tonal characteristics-the possibilities are mind boggling.

0

CJ: The technical possibilities areinteresting: I think we could achievea new standard of quality in captur-ing the sound of a symphony or-chestra. But at some point, the

Author's Note:I spoke with RCI Sound Systems'

design engineer and managing part-ner, Rick Shepard, about the com-pany's unique enclosures. His com-ments on the evolution of theirdesigns reveal the many concerns in-volved in the design of a sound sys-tem, especially when it must "fly":

The R490 was inspired by thedemands of a long-time client, whoseannual show at the Capitol Centre inLandover Maryland grew largeenough that our system of stackedcomponents was no longer going tobe acceptable-we had to come upwith a "flying" PA system within ayear. Around this time (summer1981), there really weren't any com-mercially available "flying" PA sys-tems except for Meyer; so we decidedto build our own.

After talking with many soundengineers, and some of the designersat JBL; we concluded that a hornloaded full -range box was our bestchoice. We felt the horn loadingwould give us the ability to optimizethe output of each device in the cabi-net, while also offering excellent pat-tern control.

A full -range "all -in -one" cabinetwould be easier to set up than com-ponents, with less chance for con-figuration errors.

Along with cabinet design, we alsohad to develop hanging hardware tosupport the system. About the onlything everyone in the industry couldagree on was the use of chain -motorhoists. We looked at what the largenational companies were doing, andrealized that it was too restrictive fora smaller company like ours. Wewanted the most flexibility (morecoverage angles) we could get from asingle frame; we couldn't put up a"wall of sound," nor would that havebeen appropriate for some of ourclients. Once we settled on that, thedesign phase of the hanging hard-ware paralleled the development ofthe cabinet. Our first prototypeswere ready for trial in December,

human element becomes a factorand performance begins to suffer. Ireally don't think you can improveon the orchestra balancing itself. Ithink our method of close area

mic'ing is the best compromise be-tween natural orchestral balanceand the control needed for projectionoutdoors.

RCI SPEAKER SYSTEMS1981; we used them for small con-certs at local venues to shake the"bugs" out of them. A few minormodifications were made before weconsidered the design a success.With cabinet dimensions finalized,we could now complete the hangingframe.

NO MARGIN FOR ERRORThere can be no errors in hanging a

PA; to sleep at night, we took ourideas to a company that specializedin material handling, since our pro-ject was a form of that. After consult-ation with their engineers and de-signers, we selected a steel designinstead of aluminum: for its longev-ity and resistance to abuse. A systemof staggered points was incorporatedinto this frame, permitting a rake of22 and -a -half degrees, 30 degrees, 45degrees, and 60 degrees horizontalon the cabinets themselves, ifdesired. The individual cabinethangers were attached to their re-spective enclosures only after as-sembly outside the cabinet wascompleted. The hangers carry theweight of anything hanging below it,not the cabinet; we didn't want totrust the cabinet to carry more thanits own weight-a problem I'd no-ticed in some other designs. Nylonwebbing with Aeroquip fittings wasused to suspend the cabinets fromthe frames and from each other. Wegot both our straps and the "D" ringsfor our hangers from a company spe-cializing in truck body building, coin-cidentally, they also supply ClaireBrothers. We sent all our hardwareto a laboratory for destructive test-ing, and found that the weakest linkwas the "D" ring, which broke at8,300 pounds (the typical load forthis fitting is 750 pounds). Every-thing else tested to well over 10,000pounds, so we felt very confidentabout the safety margin.

RCI cabinets are designed so thatthey will couple acoustically when"flown" or stacked-a big problemwith some of today's designs is that

they don't use the laws of physics.The R490 is a 4 -way enclosure with a90 -degree horizontal by a 40 -degreevertical dispersion. The low -frequency section uses an 18 -inchJBL 224011 woofer in a quasi "W"design horn with a 32 Hz flare. Two12 -inch JBL 2202H woofers are lo-cated to either side of the lowfrequency section: these supply mi-drange in separate 120 Hz exponen-tial horns. Upper midrange is sup-plied via a Community PC494 hornin conjunction with a JBL 2245J 2 -

inch compression driver. This ismounted in the center of the lowfrequency section. The tweeter is aYamaha 4281B: mounted above thehigh -mid horn. The cabinet is run 3 -

way active, with an on -board passivecrossover between the compressiondriver and tweeter; points are 250Hz, 1.2 kHz, and 6 kHz. We're nowusing BSS 360 crossovers with 18dB/octave slopes, and have time andphase aligned the components usinga TEF analyzer.

The entire project was completedon time, though not by much! We'vebeen very pleased with the system,and continue to amaze crews andsound engineers with how flexible itis.

A few years ago, we found that weneeded a longer throw, where dis-tributed systems or delays were notpractical or available. We developedthe R240 as a long -throw adjunct tothe R490. The R240 was designedprimarily for outdoor use, but hasproved to be very effective indoors atlarge halls, or at theaters with deepbalconies.

This cabinet has a 40 -degree by40 -degree dispersion, and is amid/high box only. Two 12 -inch JBL2202 woofers are used in the sameexponential horn design; highs arehandled by two PC442 horn/2425driver combinations. The samecrossover frequencies are used, andthe cabinet is configured to coupleacoustically with the R490. Erb

TY FORD

The Creation of a Console

Herewith, case histories of the initial design and subsequent installation ofa new console inseveral venues.

Fort Lauderdale's not a badplace to be, with the excep-tion of the occasionaltropical storm or hurri-

cane. Design engineer Tom Graefecertainly thinks so; even though agood part of his time is spent wingingoff to audio conclaves to address thegrowing number of people who arediscovering the merits of the SonyMXP-3000: a console that bears hismark.

DESIGN CONSIDERATIONSIn 1985, using the MCI JH600 con-

sole as a starting point, Graefe un-dertook the task of coming up with anew console that was quieter moreflexible, and easier to manufacture.As solid as the archetypal MCI was,changes in the way people workedhad resulted in numerous modifica-tions. Here was a chance to incor-porate the best of those after -marketdesign concepts with the latest high-technology circuitry.

Technological advances included:new hybrid discrete transistor cir-cuits in the front end, quieter opamps and power supplies, a completereworking of the grounding systems,thermal coupling of components to aheat dissipating conductive sub-strate in the circuit boards, and 0.01 -percent tolerance components.Large crystal oxygen -free coppercable replaced foil -shielded cable forhigher conductivity and to keepnoise down. Attenuation to wherethe cables ran within the console alsohelped to lower the noise figures.Newer ACN's, VCA's, and criticalpeak detectors topped off the oper-ational refinements.

Ty Ford is an independent writer,based in the Baltimore, MD area.

Graefe knew that EQ would be thereal sticking point. With so manydifferent types of EQ on the market,the only logical way to proceed was tocontinue the modular approach.After determining what circuitswere most often used, five differenttypes of EQ were implemented: afour -band sweep frequency para-metric with switchable Q a four-

band sweep frequency parametricwith fixed Q a ten -band graphic, a"Pultec-sounding" LCR (induc-tive/capacitive/resistive), and a four-band state -variable EQ.

GROUNDING ANDCONNECTIONS

"Good grounding is Rule Number1," notes Graefe. "You have to sepa-rate grounds for certain reasons. Werun our LED's from a constant cur-rent source. But even that littleamount of transient difference whenthey're turned on, if dumped into theanalog or audio ground, causes aslight click or pop, at 70 to 80 dBdown. So we have that all dumpedinto a peripheral ground whichcomes together with other groundsat one point only." Special considera-tions were given to incorporatingnew digital control technology withanalog audio circuits. "Digital andanalog grounds are separate. Other-wise, you dump all that digital stuffinto the console and it starts scream-ing at you."

Integration of the automation -sys-tem controls into the console layoutpresented additional challenges."There is an automation system inthere on an eight -bit bus that runsover ninety inches in the console,and getting that quiet takes a lot ofattention to detail. The size of thegrounds, the positioning of thegrounds, where the grounds are run

on the board itself are equally ascritical as the whole system."

Graefe found that solderingcrimped connectors reduced noise by6 dB. When combined with the newgrounding system and quieter chips,noise figures at the ACN bus were re-duced to better than 90 dB. Depend-ing on the specific routing and mod-ules used past that point, the noisefigures fall in the middle to upper 80dB range. Although efforts to im-prove the noise figures led Graefe todesign considerations that pushedthe price of the ccnsole above origi-nally projected figures, those effortspaid off. The console soon became soquiet that Sony had to buy new testgear to measure tie little noise thatremained.

ERGONOMICSFeedback from MXP-3000 users

helped Sony improve the overallphysical layout of the console. Graefeexplains, "We removed all the but-tons, knobs and assignmentswitches that are normally clutter-ing up the fader area-the ones thatyou accidentally hit at 4 a.m. whenyou're fading out, and went with aninfrared remote control with a dis-play on the fader"

Graefe takes obvious pride in howmuch attention was paid to littledetails. "Using hot -stamped knobmarkings instead of engraved onesmeant that the markings won't be-come filled with dirt, making themdifficult to read. The somewhat boxymeter housings were purposelymade that way for safe placement ofnear -field monitors."

Figure 1. Students at work at the console at the Peabody Conservatory ofMusic's Recording Arts and Sciences Department.

PATCH BAY CONSIDERA-TIONS

Nowhere is a console more suscep-tible to external noise than at thepatch bay. Ground loops, aberrantequipment interfaces, and poor con-ductivity often conspire to make fic-tion out of noise figures. Graefe ex-plains the special considerationsthat had to be made to preserve thenoise figures he worked so hard toget.

"We went to our own moldingsthere so that our jack rows are totallyisolated from one another. All thechassis grounds are brought backseparately to a central ground point.There's no current carried in thechassis anywhere in the patch bay soyou have no induced hum or noise.We use metal frame jacks, not theplastic PC mount ones. We're usinginsulation displacement -typeshielded ribbon cable with gold con-nectors that go to the patch bay."

PHYSICAL AND THERMALCONSIDERATIONS

Another important but subtle de-sign consideration of the MXP-3000is its physical displacement in thecontrol room. According to Graefe, ifyou're spending a lot of money on acontrol room with flat response to 20Hz, accurate reproduction of thatlow end will be destroyed by a consolethe size of an airplane wing that goesfrom floor to eye level. Because theMXP-3000 takes up less space, andbecause of its overall shape, its effect

on low -end response in the room isminimal.

Highly efficient heat dissipation,important for long life and stable cir-cuit operation, is achieved withoutcooling fans. Even so, most of theMXP-3000's working surfaces (in-cluding the top panel) are cool to thetouch. The thermally conductivesubstrate in the circuit boards anddesign considerations which maxi-mize convection currents help keepthe console cool. The lack of coolingfans has other advantages. No fansmeans no physical or electrical fannoise, and fewer moving parts.

Graefe believes the approach toquality taken with the MXP-3000will make it a solid part of the Sonyline for a long time. "I fully expectthat twenty years from now thething will be still sitting aroundworking, with the kind of parts we'reusing. It's state-of-the-art tech-nology as available today. In terms ofanalog technology, I don't think any-body's going to come along with aradical new concept."

SONY AT PEABODYFor Alan Kefauvei who is the

coordinator of the Recording Artsand Sciences department at the Pea-body Conservatory of Music in Bal-timore, MD, the decision to go with aSony MXP-3000 was based onseveral factors. Even though he vis-ited the Sony factory in Florida totake a first-hand look at the console,the fact that WPS (Washington Pro-fessional Systems) had one operat-

ing in their showroom was a big plus.The offer to come to the WPS show-room for some hands-on work al-lowed Kefauver to satisfy his con-cerns about how well the consolewould perform.

"I had a module go up once,with a session that

afternoon. They drove themodule up-you can't ask

for much better service thanthat."

CUSTOMER SUPPORTHaving the console "in-house" also

allowed WPS to come to his rescueon several occasions; Kefauver ex-plains, "during the installation, forexample, the old mic lines from thestudio to the concert hall were foundto ring so much that they burned outthe mic preamps. Even though it wasnot Sony's fault, WPS gave me newpreamps." According to GregLukens, head of sales at WPS, "TheMXP-3000 has transformer -less micpreamps with a 200 kHz bandwidth.

The 500 -foot, foil -shielded mic ca-bles were oscillating at 200 kHz. Wesolved the problem by installingSony's optional transformer micpreamps to support the unusuallylong mic lines." Keeping the cus-tomer happy is one of the manythings WPS does well, even at thelast minute. Kefauver remembers,

"I had a module go up once, with asession that afternoon. They drovethe module up-you can't ask formuch better service than that."

Following Sony's guidance ongrounding for the MXP-3000, theconsole was connected to the ex-isting Peabody ground field whichconsists of nine copper stakes inter-laced and buried in the ground. Ac-cording to Kefauven "When we builtthe studio; we put in a dedicatedground field. We're not even on thehouse ground or power companyground. We have our own groundsfor safety ground, shield ground,A.C. ground, everything. We run sep-arate neutrals on all of the A.C., anduse isolated ground receptacleswhich run to our own ground field."

The longer Kefauver usesthe console; the more he isconvinced that it was the

right choice.

LOW-LEVEL METERINGKefauver was the first in the U.S.

to order the MXP-3000 with VF(vacuum fluorescent) metering."For classical music recording, Ineed metering that goes down to -40dB to -60 dB. A string quartet play-ing Mozart gets damn quiet. Stand-ard VU meters which only go downto -20 dB won't do the trick for me."

Other specified options to the 36 -input mainframe include: the hard -disc automation, a number of each ofthe different EQ's, a mix of inputmodules with and without trans-formers, an extended patch bay, andextra headphone amps. His ex-perience with mic preamps in a widerange of consoles, including Mit-subishi, SSL, and Neve, still led Ke-fauver back to Sony.

"When I work in New York; I findthat most engineers like to track onNeve and mix on SSL. The SonyMXP-3000 transformer -less micpreamps are incredibly clean andquiet-transparent." The MXP-3000's broadcast mode, which al-lows the output of the mic preamp tofeed both the channel path andmonitor path independently, also ap-peals to Kefauver because it allowshim to do a multi -track backup whiledoing a live stereo mix.

WORKING DOUBLE-TIMEAnother striking example of the

console's versatility is that Peabodyhas used the console to record twoconcerts at the same time: a featwhich says all you need to knowabout its cross -talk performance.Kefauver feels the console is well -suited for training students in theRecording Arts and Sciences pro-gram, "it has proven to be extremelyuser-friendly for freshmen toseniors."

The longer Kefauver uses the con-sole; the more he is convinced that itwas the right choice. "Every morn-ing at 8 o'clock it's on and runningjust as it was the night before whenwhomever left at midnight...it al-ways works. The students and thefaculty here all comment on hownice it sounds-how musical. Thebottom line's real simple. It works; itsounds good and it's got dealer sup-port. It's hard to say that about a lotof equipment in this industry."

SONY AND THE ARMYGraig Greco, who overaccz record-

ing for the U.S. Army Band in Wash-ington D.C., had no budget restraintsto keep him from going after a moreexpensive console. Regardless ofthat, his choice was the Sony MXP-3000.

Greco also appreciatesWPS' customer support. In

his case, gettinc andmaintaining good support is

not easy.

Greco's specs called for thirty-sixinputs, eight wild faders, vacuumflorescent meters, six of each type ofEQ, single mic preamps and trans-formerless inputs. The decision torun without transformers cameafter testing a wide selection of theirown microphones. Like Kefauver,Greco had worked with Neve andSSL consoles. Like Kefauver, it wasthe sonic qualities that attracted himto the MXP-3000.

Using Dolby SR and dbx, much ofthe music he records is complex bigband and orchestral material. Afterhearing how transparent and natu-ral the console was, Greco says WPSdidn't have to do a lot of selling. Heremembers some of the things thatcaused him to go Sony: "Greg

Lukens had some brass arrange-ments on tape for a demo. He knowsI record a lot of brass. The accuracyof the valve sounds really impressedme. Big band arrangements andtrumpet arrangements can createsome very strange artifacts whencombined. You need to be able to hearwhat's going on. I feel comfortablewith the MXP-3001 The people Iwork with are purists-they need acertain sonic quality"

Greco also appreciates WPS' cus-tomer support. In his case, gettingand maintaining good support is noteasy. "We're a government office.`Red Tape' means problems. WPSworked out ways to deal with theseproblems." Throughout its two yearsof operation, Greco says the consolehas been very stable. Based on his ex-perience with Sony reliability, thestudio also bought two 5000 seriesSony reel-to-reel tape machines.

IN THE PRIVATE SECTORAt Cubic Studios near Baltimore,

Mark Davison runs a 36 -input MXP-3000 with full discbased automat-ion and four wild faders. EQ's in-clude: two parametrics, twographics, two of Sony's "Pultec-like"LCR EQ's, and thirty standard ones.

Like an increasing number ofmusicians who record their own pro-jects; he had become tired of luggingtapes from the studio in his home tolarger studios for n-Jxdown. His re-cording projects had reached a stagewhere his existing console was nolonger adequate. With the disc -basedautomation, for example, Davisoncan now store several mixes of thesame piece. He can Inen choose partsof each mix and combine them for afinished master.

Davison's ten-year history of deal-ings with Washington Music (the MIside of WPS) led him to Greg Lukens.Already familiar with Sony qualityand proven track record, the factthat WPS had an MXP-3000 on thefloor was a major consideration.Other key factors were: automation,EQ, and price. Though he hadworked with SSL and Neve (and hadalso looked into Amek, Trident,Soundcraft, and Soundtracs), cus-tomer support concerns added to hisdecision to go Sony. "They've alwaysbeen there when I've needed them,"says Davison, "and that's whatcounts."

RONALD BENNETT

Audio in the TheaterThe Broadway -bound show Annie 2 represents the new wave of thinking in production in moderntheater. It is a major production, but it closed with poor reviews while still in Washington D.C.after only a few performances. Statements made by the producers at the time (January 1990) saidrevisions to the book and songs would be made and a new production would be mounted. Therewere no negative reviews regarding the sound heard in Washington's Kennedy Center.

Abe Jacob created the sounddesign. Audio technologyfor live theater has beenslow to advance when

compared to the advances in record-ing and broadcast technique. Butnow, large scale console systems, in-telligent equalization, MIDI, anddigital processing technology wereincorporated by Mr. Jacob-one ofthe theater's true innovators. Mr.Jacob pioneered and introduced theconcept of sound design to theBroadway Theater. His many showsinclude: Hair, Jesus Christ Super-star, Pippin, Chicago, A ChorusLine, The Act, The Rocky HorrorPicture Show, Beatlemania, Dan-cin', Evita, Woman of the Year, BigDeal, and Black and Blue.

Figure 1. Abe Jacob at the console.

He was responsible for the concertsound for Jimi Hendrix, the Mamasand Papas, Peter, Paul and Mary, andmany others. Mr. Jacob is also pre-sently the Executive Secretary forthe newly organized TheatricalSound Designers Association.

THE SHOW'S SOUND SYSTEMThe system he developed for Annie

2 uses Yamaha consoles for audiocontrol, A Crown PIP system foramplification, and Meyer loud-speakers throughout. The MeyerUM1's are in a cluster of six over thehouse location and are utilized pri-marily for vocal reinforcement. TheMeyer UPA's are on each side of thepresidium for reinforcement of theorchestra. The two systems do not

).tmiGaftz

' "trofter -

intermix-only vocals appear in thecenter cluster and only music ap-pears in the side cabinets.

The main mix console is a YamahaPM3000-40. It accepts the fifteenSennheiser RF inputs and therhythm section of the orchestra, in-cluding all the drums and piano. Thefive-foot mics also appear on the con-sole.

A Yamaha PM1800-16 is used forthe orchestra sub -mix, primarilystrings and woodwinds. A YamahaDMP7 Digital Mixing Processor isused for effects mixer and receivesinput from cart machines and DATmachines, and with some specificpresets, mixes those as effects,changes EQ and routes them to thePM3000 console. The DMP7 is ableto store and recall all of its equaliza-tion, level and signal processing set-tings on cue: a truly powerful devicefor live performance. Additional sig-nal processing includes YamahaDEQ7 digital equalizers andYamaha SPX1000 digital effectsprocessors. Meyer CP10 equalizersare used for both program EQ's andinsert EQ.

Mr. Jacob's design philosophy aimsat creating a system of "maximumcontrol with maximum invisibility"

He also said, "to reinforce, notamplify the system, the systemshould be transparent." The systemforAnnie 2 is large, versatile, robust,sophisticated, and yet simple tooperate. Duncan Edwards, Mr.Jacob's assistant and the productionsound engineer for Annie 2 mixesthe show.

He said, "the setup is mixing con-sole and reinforcement system, it isall designed to not break the illusionof the show"

Special effects, both via cart ma-chines and DAT are used throughoutthe show, but as Mr. Jacob said, "Wereally only use special effects to cre-ate moods."

For example, he uses a YamahaDEQ7 to create a 1930's radio effect.A Lexicon 480L and the YamahaREV5 are used together to create aYankee Stadium sound.

For microphones, they use a Senn-heiser MKH70 foot microphone forfoot mic'ing, a MKH40 studio micro-phone is used for the orchestra, witha MKE2 with K3U capsules used forstrings, and the radio frequency(RF) mic is the SennheiserSK.2012TVL.

HOT RFRF mics in the Washington. D.C.

area can present some real prob-lems. With all of the government andsecurity communications, the areaaround the Kennedy Center is one ofthe hot test RF areas in the UnitedStates. A technician was brought into do RF spectrum analysis and,based on the testing, the system wasset to 500 to 600 MHz RF in the UHFband because it was found that thisband had the least amount of RF in-terference. The choice of the 500-600 MHz provides them with somedegree of RF protection.

Duncan Edwards is the Produc-tion Sound Engineer for Annie 2,and Daryl Bornstein is the SoundDesign Associate. Mr. Edwards said,"The stage managers are just begin-ning to learn to deal with RF micro-phones. They are now designatingtime for people to come in to bedressed with RF microphones."

Mr. Jacob noted, "In the past, theyhad put RF microphones on actors atthe start of the show, and duringbreaks and intermission, they wouldmove the belt packs and micro-phones to different actors to get theirlines. The new system puts the mi-crophone on the performers' headsand allows them to change only theRF transmitters if needed. I prefer toleave a speaking performer's RF micon, barring a special situation, toavoid mix-ups and problems as-sociated with equipment changes-this cuts down on the number of mis-takes that can be made."

I Ail oulll

111

Figure 2. The PIP screen on the Macintosh screen.

STAGE FOLDBACKIn the stage foldback system, they

are using Meyer UPM loudspeakerswith sub -woofers. They are trying toput only the orchestra in thefoldbacks, but often have requestsfrom the performers to include the

Figure 3. Ampli-fier racks for theKennedy Centerproduction.

dialogue RF microphones in thefoldback system.

Through a combination ofmethods, they have been able toshow the performers that it is not thebest way to work: it is a real edu-cational effort.

01

A very clever low-cost tool used onAnnie 2 is a video camcorder whichhas been installed to allow the mixer,via a monitor at the mix location, tomonitor the RF system. The cam-corder also records a picture of theRF system and an audio feed duringa performance to allow the mixer totrace down any report of a micro-phone problem and determine if it isan audio or RF problem. This videorecording also serves as a system his-tory of each performance and helpsin planning any system changes ifthey are in order.

The Kennedy Center Opera househas a 2,000 seat capacity. Mr. Jacobdesigned a PL system with a Vegaeight -channel wireless PL and fourchannels of walkie-talkie. A specialpart of the performance required asound effect to come from a prop onthe stage. Mr. Jacob designed aunique RF wireless effect unit thatuses a small battery -powered guitaramplifier and a battery -powered RFreceiver buried into the prop to actu-ally have sound effects coming fromwithin the performance area.

SYSTEM CONTROLThe system output is through a

Crown PIP system with MA 1200amplifiers. This allows the operatorto interrogate the amplifier and ad-just levels and have interactive con-trol of the system. The Meyer SIMsystem utilization lets them not onlyequalize the system, but actuallytime -align the system for maximumintelligibility and frequency re-sponse for both music and speech."The time delay in the main systemis time -delayed to the principlesource on stage, wherever thatmight be. In the future, we hope to beable to program the system to followthe source as it moves around. Wewill be able, during the show, tochange the central time -delay loca-tion," said Mr. Jacob.

The SIM system set-up for Annie 2is being performed by Kyle Takemoriof Meyer, and using the IQ PIP sys-tem and MA 1200's from Crown; forany single seat in the house, he cancontrol everything in the theater: hecan turn-on/turn-off channels, setup time -delays, adjust levels, equal-ize the system, balance the system-

basically run the system from one lo-cation. Mr. Jacob commented on theSIM system, "Once I have the SIMequalization set-up for the principalroom in which the play is to be per-formed, there is a direct correlationin subsequent locations. If thetheater is the same size as the roomthat the show was EQ'ed in, I feelthat the system can go from room -to -room; the EQ's and the time -delay do not appreciably change."

Documentation and system his-tory are now of major importance inlarge audio systems, not just for thebasic design, but for the day-to-daymanagement of the system. The en-tire system is documented in organ-ized three-ring binders for hardcopy,and all system information is storedin the Macintosh computer whichalso controls the PIP system.

Once again, Mr. Jacob has crea-tively utilized the latest audio tech-nology and thought, and hasdeveloped a robust high quality rein-forcement system which will workwell in any venue. The sound systemis transparent to the audience andtruly maintains the illusion of thelive performance.

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MARTIN GLASBAND

Soundly Engineered A.C.: The Answer To Audio Noise

1t's truly surprising howlittle is understood amongelectricians and studiopersonnel about the A.C.

power systems that feed sophisti-cated audio electronics in recordingstudios. Why is it that techniciansresort to ground lifters whenever un-wanted noise appears in a studiosound system? Does anyone realizehow dangerous that is? Why do theyattempt to quiet a studio by drivingground rods which often fail? Whydoes there seem to be a widely heldbelief that A.C. power and groundingare inherently "dirty" things? Theanswers to these questions are quitesimple. There are simply no ade-quate standards in existence at thistime. As a result., A.C. power andgrounding are lightly regarded andremain very misunderstood.

Recently, at an electrical seminar,it was stated by the instructor thatonly now are the unique require-ments of high-tech installations fil-tering down to us (electricians). Butthat was about all he had to say.Aside from isolation transformersand isolated grounding receptacles,

Martin Glasband is an ElectricalEngineering Consultant and li-censed Electrical Contractor basedin Selma, Oregon. His backgroundis in industrial, studio, and techni-cal power system design. Formerly,he has designed and built systemsfor ABC Radio Network, KCETTelevision, New World Pictures,and Baby '0 Recorders. Currently,he is working on a new studio com-plex for Music Animals and Chris-topher Huston Design in Los An-geles.

not much else is being disseminated.And the noise goes on. So, in thespirit of putting the myths to restonce and for all, it has been under-taken in this article to provide for acomprehensive and clear under-standing of A.C. power and ground-ing techniques for recording studioswhich will provide for both safe andnoise -free operation. There are twoareas that will be addressed:

1) A.C. Supply (source of mostnoise within the studio)

2) Grounding (transmission ofnoise within the studio and from out-side sources)

A.C. SUPPLYTo properly appreciate what is

being presented here, it is first neces-sary to accept the idea that studioelectronics begin at the A.C. isolationtransformer outputs, not at the am-plifier or console power supply as iscommonly believed to be the case.There are a number of A.C. systemswhich can furnish a 120 -volt supply.Figure 1 is an example of the mostcommon type of 120 -volt A.C. sys-tem in the U.S. This system has adual voltage output (120/240 volts).The center tap on the outputs isgrounded and is commonly calledthe neutral. Even if only one side ofthe outputs is utilized for studiooperation, this system is not truly

Figure 1. The most common U.S.120 -volt system.

Primaryvoltage

120V.(neutral)

(U g-ound)240V.

compatible with audio electronicsbecause it is unbalanced. In otherwords, the wires in a 120 -volt circuithave unequal potential to earth orreference ground White wires(neutrals) in the wiring system aregenerally an indication that un-balanced power is being fed to thestudio electronics.

UNBALANCED POWERBoth 120/240 -volt delta and

120/208 -volt three-phase systemsemploy a neutral circuit wire when120 volts is used and, likewise,supply unbalanced power. All sys-tems with neutral conductors supplyunbalanced power because neutralconductors are grc unded and haveno potential. Figure 2 is an exampleof how most studios with a 120 -voltisolation transformer are commonlysupplied. As is evid ant, the same sit-uation exists here as with the othersystems. The grcunded (neutral)side of the system unbalances thesupply.

Before we discu balanced A.C.(equi-potential line voltage), let's ex-amine an RF filter on the line side ofa power supply anc look at the prob-lem unbalanced power creates. Asdemonstrated in Figure 3, thecapacitors (which act like resistors inan A.C. circuit) pass current directlyinto the equipment chassis. There is

Figure 2. The most commonstudio isolation system.

Primaryvoltage

(iso-ground)1 20V.

(neutral)

120V.

120V.

Current-* flow r"

[ _

(ground)

(neutral)

(U -ground)

Figure 3. Capacitors act as resis-tors in AC. circuits.

a cumulative effect of all RF filters ina studio. The more equipment isused, the more noise gets dumpedinto the grounding system throughthe "U" -ground terminals on the re-ceptacles. Though exotic groundingmethods have been devised to routethe noise away from the system, thematter of eliminating RF at itssource has not been addressed. Basi-cally, the more pieces of equipmentthat are used, the higher the noisefloor of the system. Unbalanced A.C.is probably the single greatest sourceof noise in a recording studio.

BALANCED A.C.There is only one way to deal with

this source of noise-balanced A.C.Just what exactly is a balanced A.C.supply? In the electrical industry,this is referred to as a 120 -volt splitphase (or two-phase) system. Bothline conductors have equi-potential(about 60 volts to ground and 180degrees out of phase) voltage. Now,let's look at Figure 4: an RF filteroperating with a balanced powerinput. Note that current flowsthrough the capacitors on both sidesof the RF filter. Howeve4 in this rase,no current gets dumped into thechassis because both sides of the fil-ter, operating at the same voltage of180 degrees out of phase, cancel thepotential at the common chassisground. It's easy to see why balancedA.C. is the only effective way of elimi-nating A.C. noise at its source.

So, let's now look at Figure 5: some120 -volt A.C. systems which arebalanced. You probably recognizethis transformer as the same oneused in Figure 2. Most studios with a120 -volt isolated power system haveone of these. The difference here inthis application is that the groundhas been lifted from the secondary-this changes the whole system.Formerly, it was operating in the120 -volt single-phase mode, now itwill run as a two-phase system. Themain problem with this, however, isthat there is no longer a large enoughavailable fault current on either side

760V.

---17'Current ,

* flow i

,---._

120V. 1--,T

60V. t

Figure 4. This is an RF filterwith a balanced power input.

of the output to cause a circuitbreaker to trip. In the event of ashort to ground, the entire systemwill simply revert back to its formersingle-phase 120 -volt mode of opera-tion. The secondary side of the sys-tem will only reference to ground.

To a studio enginee4 it would prob-ably be somewhat discomforting tothink that all of his equipment wasdraining somewhere out there in themiddle of a ground circuit. Probablyworse though, is what an electricalinspector would say if he noticed thatthe studio was operating with an un-grounded system. None of this is in-tended to discredit the viability ofthe system. No doubt that the equip-ment will run a lot cleaner. It's ironicthough, when one considers thatcommercial use of electricity hasbeen around for a comparativelyshort period of time. Way back whenthe industry was in its infancy, thiswas the only type of system commer-cially available. Now, once again, weare resorting to its use to solve ourhigh-tech problems. Today, un-grounded systems are practicallyunheard of. Two-phase ungroundedsystems are even more scarce. Theproblem may be in convincing thelocal authorities that it is safe and vi-able.

THE BEST SOLUTIONProbably the best solution to all of

the above is to change all of the cir-cuit breakers to two pole GFCIs(ground fault circuit interrupters).This should also entail the replace-ment of all the white neutral conduc-tors with some other color. In theevent that some circuit suddenly, forwhatever reason, shorted to ground,the GFCI would immediately tripand the integrity of the system wouldbe maintained. This would also ratea solid "10" on a safety scale. Becauseof the effectiveness of this type ofprotection, the local electrical in-spector will probably OK the system.But in the event that he doesn't, youwould be well-advised to changetransformers. A local code variance

Primaryvoltage IIJ

1

60V.(iso-ground)

1

60V.

Figure 5. Most studios with a120 -volt isolated power systemhave one of these.

is possible: citing the use of un-grounded isolated systems in hospi-tal operating rooms (ref. N.E.C. 250-5b ex. 4 & 517-104).

There is one other minor hitch inoperating a 120 -volt isolation trans-former in this way. Commonly, thepotential between each side of thesystem and the ground reference isnot perfectly balanced. A differenceof 5 to 10 volts is common. This, how-eve4 is only a minor imbalance com-pared to a single-phase system andshould probably be ignored. Therewill still be a drastic reduction in thenoise floor. It may be a good ideathough, to use a dual voltage moni-toring device such as a pair of analog,or analog to digital voltmeters be-tween each A.C. line and ground.This can be a made-up unit andplugged into any receptacle at a con-venient location. It is possible,though, to avoid all of these prob-lems.

Let's now look at Figure 6: onemore type of 120 -volt A.C. system.This is the optimum type of the two-phase system for studios. It is re-ferred to as a 120 -volt two-phasegrounded system. The transformeris called a 240 to 120/60 -volt isola-tion transformer. The primary volt-age doesn't necessarily have to be240 volts. 240 was only used as aspecification example for the pri-mary side. 120, 208, 277, and 480volts are also very common voltages.Care must be taken when orderingthe transformer in that the primaryvoltage is what is available. Also, acenter tap on the secondary side is acrucial requirement. 120/60 indi-

Figure 6. This is the optimumtype of the two-phase system forstudios.

Primaryvoltage

60V.(iso-ground)

1

60V.

cates a center tap secondary. Beextra sure when orderingyour trans-former because of the importance ofa center tap. The reason for this willsoon be apparent.

This transformer should not beconfused with a 60/120 output trans-former. Both provide 120 volts, butonly a 120/60 can be grounded whilestill maintaining a two-phase supply.Only the 120/60 system has by de-sign, two outputs 180 degrees out ofphase, with a common center tap.When the center tap is grounded,equal coil output windings on bothsides, rather than a typically unevenmagnetic flux dispersion, determinethe voltage at each output. Thisguarantees a near -perfect balance.Furthermore, referencing the centertap to ground enables the system togenerate enough fault currentpotential to trip a circuit breaker.This is a very important safety con-sideration. Costly GFCI breakers arenot needed. The grounded secondarywill also please the inspector.

Two pole breakers must be used tofeed every circuit in all 120 -volt two-phase systems. But as far as overloadprotection is concerned, conven-tional two -pole magnetic trip circuitbreakers may not provide adequateprotection. At lower than usual oper-ating voltages, they may not tripunder overload as designed (240 -voltcircuit voltage). To remedy this, it isrecommended that HACR-typebreakers be used. HACR breakersprovide a secondary tripping mecha-nism (thermal overload) which reliessolely on current. Many standardbreakers are already rated asHACR-type breakers, so theyshouldn't be hard to find. Falsealarms are not a problem.

NEW ISOLATIONTRANFORMERS

In case you find yourself purchas-ing a new isolation transformer,there are some other importantspecifications to be aware of. First ofall, there is the matter of the electro-static shield. It's not commonlyknown that an isolation trans-former's protection against un-wanted eddy currents can vary con-siderably. Use of a transformer withan electrostatic shield will greatly re-duce unclean A.C. as a noise source.The specification that applies is thetransformer's common mode rejec-tion. In most cases, 80 dB is ade-quate, but higher noise rejection is

available if needed. With the adventof newer and quieter digital equip-ment, 100 or even 120 dB may benecessary to maintain a sufficientlylow noise floor.

The other specification one shouldconsider is transformer temperaturerise. Temperature rise is simply anindication of how hot the trans-former will run under maximumload conditions. 150 degrees isstandard in most cases. But if youare considering growth, or perhapsat times pushing the transformerbeyond its rated output, an 80 degreetemperature rise will allow thetransformer to be overloaded by asmuch as 35 degrees.

This lack of clear directionpertaining to isolated

grounding within asplit -phase power system is

probably the main reasonwhy studio electrical

systems have remained inthe Dark Ages up to now.

This could save a lot of moneydown the road, if your plans call forit. A lower temperature rise couldalso save money in air conditioningexpenses. To maintain clean A.C., itis recommended that several 1:1A.C. line transformers be kept onhand for use with unbalanced equip-ment, or otherwise transformerlesspower supply gear. Without them,noise dumped into the A.C. orground system is very likely. Butdespite all of our best efforts, somenoise remains in the studio. Not allnoise is studio A.C. related. We mustlook elsewhere to find answers.

GROUNDINGFor a variety of reasons, current

gets dumped into the grounding sys-tem, both from within the studio andfrom outside sources. The tendencyis that high gain and high impedanceequipment, being very sensitive toEMI, will detect this noise and pass italong into the rest of the audio sys-tem. Depending on the severity ofthe noise, other equipment as well,can similarly be affected. The task,therefore, is to suppress noise trans-mission without compromising theA.C. ground. Ground lifters effec-tively block noise transmission, butthey do so at the expense of safe

operation. By not maintaining shortcircuit potential in metallic equip-ment chassis, "live" chassis condi-tions are possible and circuitbreakers are rendered ineffective.The solution is not to create acompletely independent audioground-this would be solving oneproblem and inadvertently creatinganother.

It's somewhat comical, if nottragic, to think of all the ground rodsstuck in the earth, abandoned, forthey failed to perform as intended.Your local electrical inspector wouldfrown on their use anyway, as a sepa-rate or supplemental studio ground,because more than one groundsource is proh-bited. Besides,another ground pa:h would create aloop which could result in even morenoise. Within the National ElectricalCode (N.E.C.) there are a multitudeof regulations surrounding (but rela-tively few directly addressing) ourobjective, which is to provide a safeand noise -free grounding system. Toadd to this confusion, there is no ref-erence at all to 120 -volt two-phasegrounding, and only one small para-graph which refers to an isolatedgrounding system. This lack of cleardirection pertaining to isolatedgrounding within a split -phasepower system is probably the mainreason why studio electrical systemshave remained in the Dark Ages upto now. Unfortunately for recordingstudios, the code is more concernedwith safety than with "clean" opera-tion.

WORKING YOUR WAYTHROUGH CODE

So here we will make an attempt tobeat a path through the various codesections which do apply, and formu-late a method of grounding whichtakes into account both the appli-cable code safety requirements, andthe "clean" requirements of studioelectronics. First of all, what is iso-lated grounding? Isolated groundingis a method of grounding that re-duces electrical noise by employing adiscreet grounding conductor whichdoes not connect to the conduit sys-tem. It utilizes isolated ground re-ceptacles on which the groundingterminal is not mechanically con-nected to the mounting means of thereceptacle. According to the code,the isolated ground circuit wires areto terminate at an equipmentgrounding bus in the main iso-panel.

To

structuralsteel

Iso-ground 4444444 4444444Othersystemgrounds

Supplementalground rods

Water pipe

Figure 7.This is an example ofwhat is termed building -noise -re-duction grounding.

For our purposes, that too must beisolated, because the panel box isconnected to the conduit system.

The next logical question is, wheredo we go from here? Where do wefind a "clean" ground source that islegally permissible? First let's look atthe grounding electrodes that are al-lowed. In the N.E.C., Article 250-54specifies that only one electrode (sys-tem) may be used for all services andequipment in a building. Addition-ally, in Article 250-26c, effectivelygrounded cold water pipes and struc-tural steel are listed as the primarytypes of electrodes to be used for amain grounding connection. Thisgreatly reduces our options. Coldwater pipes and structural steel areelectrically -bonded together; thusthey are part of the same electrodesystem. This doesn't preclude theuse of supplemental ground rods,provided that they are integratedinto the building's grounding elec-trode system.

In Article 250-26c, it also states,"The grounding electrode shall be asnear as practicable to, and prefera-bly in the same area, as the ground-ing conductor connection to the sys-tem." In most systems, thegrounding connection is made at theneutral bus. In a 120 -volt two-phasesystem, there is no neutral bus.

Unlike a single-phase system,none of the power conductors aregrounded. Howeve4 the system'sequipment is required to begrounded. Therefore, it is concludedthat the only possible point of maingrounding connection is the equip-ment ground bus (main iso-groundbus). So according to the code, it is in-tended that you connect the iso-ground bus directly to the closestwater pipe or structural steel mem-ber (bypassing the iso-trans former).

16d-i6di1 Main ground bus

Figure 8. This method is often referred to as daisy -chain grounding.

SPECIAL CONDITIONSWhen using a 120/60 center tap

system, the center tap is regarded asthe equivalent to a neutral. The cen-ter tap, therefore, is to be groundedas described above. Additionally, themain iso-panel box is to be connectedto the secondary center tap. The iso-ground bus needn't be connected tothe center tap, as will be explainedshortly.]

In many oases, the nearest coldwater pipe or structural steel mem-ber is adequate. But keep in mindthat in the code, the words "effec-tively grounded," (primary elec-trode), and "as near as practicable,"are used. Herein lies a matter for in-terpretation and judgement. Justhow "effectively grounded" (clean inan audio sense) is this primary elec-trode? And, just how close is "practi-cable" (again, clean in an audiosense)? Recently, in a six -story build-ing in Los Angeles, some techniciandid a spectrum analysis on the struc-tural steel. The results were a veri-table rainbow of frequencies pre-sent. So, structural steel was ruledout as a primary grounding elec-trode. Additionally, the cold waterpipe in the area (5th floor) alreadyhad numerous transformer second-aries grounded to it. Anyone who hasever lifted a live center tap from acold water pipe has seen the sparksfly. So, how could this water pipe bean effectively grounded electrode,especially when the iso-ground con-nection is made in close proximity?Quite simply, it is not. Groundingelectrode systems are allowed to beas high as 5 ohms above true earthground.

If an isolated ground circuit in astudio is permitted to circumventnoise in the grounded conduit sys-tem, how then could a cold waterpipe, with other systems alreadygrounded to it, be any better? Thereis possibly only one way: Figure 7 isan example of what is termed build-ing -noise -reduction grounding. Theobjective here is to be as close aspossible to the earth, making any im-

provements to the grounding elec-trode system between the iso-groundcontact and the other system'sground contacts. This method of pri-mary grounding effectively sup-presses noise transmission fromsources outside of the studio.

If necessary, a plumber can becalled in to install an undergroundwater pipe to a remote faucet for amore isolated ground contact point.Or when there is very dry or sandysoil, a deeply buried chemical groundsystem may be used where sup-plemental ground rods are indi-cated. These improvements to thebuilding's main grounding electrodesystem are in line with code require-ments. Though there may be otherprimary grounding methods, it isdoubtful that there is much room forimprovement. When this method isnot used, studios are more subject tooutside sources of interference.Some noise can be difficult to traceand very expensive to eliminate.Proper primary grounding can be avery valuable first line of defense.

BROADCAST RFIf broadcast RF is a problem, pri-

mary grounding is not the answer-shielding is. The only reliable solu-tion to broadcast RF interference isto wrap the control room with coppermesh. Commonly, this method isused in radio stations, where thebroadcast tower is in close proximityto the broadcast booth. When instal-ling a room shield, care must betaken to insure continuitythroughout the entire screen. Propergrounding of the shield is, of course,also mandatory. Alternative materi-als which can be used include leadand mu -metal. But these are quiteexpensive and, in most situations,aren't a significant enough improve-ment to warrant the extra expense.If outside noise sources other thanbroadcast RF are suspected, a testcan be made by lifting the mainground conductor. If the noiseceases, the source of the interferenceis certainly outside of the studio. But

0Console

0

Main ground bus Sub ground bus

Figure 9. An example of a star -grounding network system.

if the noise continues, the problem isprobably within the studio ground-ing distribution. So, let's now look atsome grounding distributionmethods and explore the ways ofsuppressing noise transmissionfrom sources within the studio itself.

Figure 8 is an example of how anisolated ground system is commonlywired. This method is often referredto as daisy -chain grounding. Iso-ground conductors are looped in ser-ies from receptacle to receptacle (aschassis are looped from chassis tochassis). What you have here is atypical problem studio with a multi-tude of non-linear ground planes.Various potentials exist betweenchassis. 12 -gauge wire, commonlyused as a ground conductor; is moreresistive than one might think. 50feet contains approximately .1 ohmsresistance.

The problem is generally onewhere the resistance between chas-sis is less than the resistance be-tween each chassis and the referenceground. There is no common linearground plane. EMI transmissionalong a common ground circuit oftencreates problems. One massiveground wire run throughout the sys-tem to every "U" -ground would beideal, but the cost would be prohibi-tive.

There is, however, a cheaper alter-native: Figure 9 is an example ofwhat is called a star -grounding net-work. Though star -grounding hasbeen around for a few years, its im-plementation has been rather slow.In conjunction with a properly de-signed, isolated main grounding sys-tem, it is a very efficient way of sup-pressing noise transmission, and itsuse is highly recommended. For thesake of emphasis, and for those whohave not yet heard of star -ground-ing, let's review it. In essence, eachiso-receptacle has its own discreteground conductor routed to a com-mon ground bus. Where there ismore than one breaker panel, modi-fications can be made to avoid ex-tremely long ground runs. Addi-

Console

tional ground buses appropriatelycalled "star clusters" should be in-stalled in each panel. These addi-tional ground buses are individuallyfed by a large ground wire originat-ing at the main iso-ground bus. Theobjective is to maintain a relativelylinear ground reference plane. Eachchassis is individually referenced tothe same reference ground plane.

If current somehow gets dumpedinto the system, the potential is uni-formly raised in every chassis from asingle reference ground point. Addi-tionally, the resistance between anytwo chassis, in every e_qe, is greaterthan the resistance between eachchassis and the system ground refer-ence. Therefore, noise transmissionis greatly reduced.

Even a very noisy chassis tends tobecome invisible to the rest of thesystem. To achieve a more uniformpotential in equipment chassis, thelength of the ground wires should beconsidered. Use of larger conductorscompensate for longer runs. There isa table of trade size conductor prop-erties in Chapter 8, Table 9 of theN.E.C. for sizing ground wires.

Properly balanced A.C.supply eliminates the sourceof most noise, and properly

designed grounding willeffectively block any

residual noise transmission.

Perhaps the most difficult place toinstall a star -ground system is inequipment racks. Metallic chassisbonding and plug strips defeat astar -ground system. There are, how-evei; ways of coping with this situa-tion. Racks made of wood, or othernon-conductive material used inconjunction with field -made plugstrips (such as 2100 series Wire -mold), maintain the integrity of thestar -grounding. At the very least,digital and high impedance equip-ment should be mechanically iso-lated and discretely grounded. In

some cases, where switching powersupplies are used in digital gear,high -frequency hash may be dumpedinto the grounding system. This canpose a unique problem in a studiogrounding network. The reason forthis is that high -frequency noise re-quires a very large ground conductorto be effectively dissipated. This canbe especially true when digital andnon -digital gear are located in closeproximity to the ground bus. Ratherthan go to the expense of installinghuge ground wires, an alternativemethod is suggested.

A cheaper solution is to install aseparated grounding system for digi-tal equipment. This would, of course,be called a double -star system. Thisalternate system, needing only tomeet minimum code requirementsas digital equipment, is far more"forgiving" than analog equipment.

A separate ground bus is installed,with its own main ground conductor,to the nearest available primary -grounding electrode. The iso-groundcircuit wire can be switched to the al-ternate ground bus wheneverneeded: this will effectively isolatedigital equipment noise from therest of the audio system.

CONCLUSIONRunning an audio system without

proper equipment grounding willwork, but it is very unsafe. A.C. cir-cuits need a ground reference be-cause circuit breakers are renderedineffective without a low -resistanceground fault path.

By not maintaining this short cir-cuit potential, extremely hazardousconditions can develop. As far as anelectrician is concerned, there is noother reason for a ground wire. Toelectronics personnel, however, aground represents a shield againstunwanted noise. Grounding, as withelectricians, is used as a reference.

But these are two distinctly differ-ent applications. It takes careful in-tegration of both to insure that astudio grounding system both pro-tects electrically and shields elec-tronically. A.C. noise problems caneasily be avoided.

Properly balanced A.C. supplyeliminates the so arce of most noise,and properly designed groundingwill effectively block any residualnoise transmission. There is no needfor compromise when careful A.C.engineering is employed.

BRENT HARSHBARGER

Equalization in Church Sound One of the most widely used dev-

ices in audio is the equalizer. Anequalizer can be an extremely usefultool if used correctly. Equalization isone of the most involved ingredientsin the field of audio, and if usedwrong, the worst component inaudio. To begin this topic, we will belooking at the various types of equal-izers, followed by some applicationson how to use them properly.

To clearly understand equaliza-tion, we have to understand a littleabout what sound is. Sound is madeup of vibrations. For example, if youpluck a guitar string, it will moveback and forth. Each time it movesin the opposite direction it pushes airmolecules; and we determine itsfrequency by how many times it goesback and forth in a complete cycle inone second. The audio spectrumstarts at 20 cycles per second (orHertz) and goes to 20,000 Hertz (20kHz), although only young people

10

20

30

40

50

7020

C

(r)

can hear in this range because ourhearing deteriorates with age (Fig-ure 1).

Octaves, Fundamentals, and Har-monics. These are terms that de-scribe the relationship betweendifferent frequencies. Musicalsounds are made up of fundamen-tals, which are usually the strongestfrequency. For example, if you hit aconcert "A" on the piano, the fun-damental frequency is 440 Hz. Anoctave above that is two times thefundamental or 880 Hz, and an oc-tave below would be 220 Hz. Again,we will use the 440Hz to explain har-monics. Harmonics is what gives ustimbre in music.

Therefore, if the fundamentalfrequency (also called the first har-monic) is 440 Hz; the second har-monic is 880 Hz, or twice the fun-damental; and the third harmonic isthree times the fundamental, whichwould be 1320 Hz. Knowing about

500 Hz1000 Hz2000 Hz

3000 Hz

4000 Hz

6000 Hz

8000 Hz

30 40 50

Age (years)60 70

Figure 1. Hear-ing loss tends todeteriorate withage, although en-vironment alsoplays a signifi-cant part.

octaves, fundamentals, and har-monics will help you understand theequalizers and what they control.

EQUALIZERS AREEVERYWHERE

Everyone has used an equalizer atsome point in time. The equalizer (inone of its simplest forms) is the bassand treble controls on a consumerstereo. By turning the tone controlsin either direction, we increase ordecrease the tone. This type of equal-izer works by boosting or cuttingabove or below a specified frequency.Figure 2 displays an example of howthis works. The frequency that weare going to choose is 100 Hz. Usethe treble and bass pots. If we were totake the bass pot and turn it all theway to the right; we would increaseor boost all the frequencies from 100Hz and below to a +12 dB level. Now,if we were to turn the bass pot all theway to the left; we would decrease orcut all the frequencies below 100 Hz.It would work the same way for thetreble pot but at the other end of thefrequency spectrum. Therefore, ifsomeone came up on Sunday andsaid that you have an 80 Hz shelvingbass control; you would know exactlywhat you are controlling with thatpot.

Most low -to -medium pricedmixing consoles have a three -bandequalizer on each channel. This con-sists of high (treble) and low (bass)frequency shelving type, with a thirdpot for a mid -frequency. The mid -frequency is what is called a peak/dipor boost/cut, which works on a singlefrequency. Figure 3 displays how thisworks. The single frequency in thisillustration is 800 Hz, which is calledthe center frequency. Even thoughwe are only increasing or decreasinga single frequency centered at 800Hz, the adjacent frequencies willalso be affected. How many of these

+12

12 I I

`'` 100 200 400 800

-12_,12 -12-.12TREBLE BASS

(A) SHELVING @ 100 Hz

+12

1250 100 200 400 800

-12 +12

TREBLE

(B)

.12

0

12800 1600 3200 6400 12K

- 12"x.12 -12 +12

TREBLE E ASS

(C) SHELVING © 3200 liz

Figure 2. Basic tone controls. At (A) bass boost, at (B) bass cut, and at (C) treble boost.

adjacent frequencies is determinedby what is referred to as "Q".If the Q is referred to as a Hi -Q, thenit affects very few frequencies adja-cent to the center frequencies; and ifit has a Low -Q, then it affects severalfrequencies (Figure 4).

SWEEPABLE EQSo far, we have been talking about

several "fixed" equalizers, whichsimply means that the frequenciesare set and cannot be changed. Moreand more mixing consoles are com-ing out on the market with variablecenter frequencies (what is com-monly called sweepable or sweep eq).Figure 5 shows that we can nowmove the boost/cut center frequencyto a more desired location. For ex-ample, sometimes an acoustic guitarhas a tone that when strummedhangs on longer than any other. If itsounds undesirable, we can remedythis by boosting the sweepablefrequency, then turning the sweeppot until that frequency jumps out,and then turning the boost/cut pot tocut that frequency until it soundsnatural (and in place with the rest).Also, be aware that poor mic'ing canalso cause this problem; therefore,check your mic'ing first, before youwork it out with EQ.

Now, onto everyone's favorite playtoy-the graphic equalizer. The twomost popular graphic equalizers arethe octave and the third octave. TheISO (International Standard Or-ganization) has a standard on thecenter frequencies for the graphicequalizer, which most manufac-turers follow. The ISO centerfrequencies for an octave EQ are:

16, 31.5, 63, 125, 250, 500, 1,000,2,000, 4,000, 8,000, and 16,000 Hz.

Although most manufacturers fol-low this standard; you will still onlyfind 10 sliders instead of the 11frequencies indicated because mostspeakers cannot reproduce this low,and if they could, we couldn't hear it.The third octave equalizer has threebands per octave which are:

16, 20, 25, 31.5, 40, 50, 63, 80, 100,125, 160, 200, 250, 315, 400, 500,630, 800, 1,000, 1,250, 1,600, 2,000,2,500, 3,150, 4,000, 5,000, 6,300,8,000, 10,000, 12,500, and 16,000Hz.

Again, notice that most third oc-tave equalizers do not have thefrequencies below 31.5 Hz. Graphicequalizers have fixed frequenciesand fixed "Q's" and they work withthe boost/cut characteristic dis-played in Figure 6.

TYPICAL CHURCH EQIn a typical church audio system,

we usually have two equalizers in theaudio path; the first being the EQ inthe mixing console's channel, whilethe second is the house or monitorEQ. Both equalizers serve differentpurposes. The equalizer in themixing console is used to give the mi-crophone the flattest (or smoothest)frequency response. The graphicequalizer is used to give the speakers(along with the rest of the house) theflattest frequency response. There-fore, any tonal ad ustments shouldbe made with the equalizer on themixing console, while the graphic orhouse equalizer should never betouched once it is set.

Before going on any further; Iwould like to use the story I used lastmonth as an illustration, but takingit a step further. For those of youtuning in for the first time; or forthose of you who missed last issue'ssegment, I'll brief_y go over it. Thestory was about a church choirhaving problems with hearing: "Wejust can't hear!," the choir said, al-though the SPL was 6-9 dB abovewhat the house was getting. So weturned off the monitors until theservice started and brought the levelup until the music pastor said it was

Figure 3. A three-way equalization control. At (A) maximum range, at (B) midrange boost centered at 800 Hz,while at (C) midrange cut at the same frequency.

Center

50 200 800 3 2K

+12

-12 I I

50 200 800 3.2K

12 .12 -12-+12TREBLE MIDFREQUENCY BASS

+12

0

-12 I I

50 200 800 3.2K

0 0

-12 +12 -12 .12 12 .12TREBLE HIDER EOUENCv BASS C,..)

(A) (B) (C)

Center Center+12

0

-12

(A)

500 1000 2000High Q (Hz)

+12

-12500

(B)

1000 2000Low Q (Hz)

Figure 4. At (A) Hi -Q offers a narrow frequency band, while at (B) low -Qspreads it out.

-12 +12 500 4K -12 +12 -12 +12Hz

TREBLE MID BOOST BASSFREQUENCY CUT

OK. Well, when the pastor said stop,the level was lower than we normallywould have set it. Problem solved. Orwas it? Yes and no. Yes, we cured thesymptom, but we didn't solve theproblem. What was the problem?The problem was the location of thechoir monitors. The choir was sittingin an acoustic shadow; therefore,they were not getting enough directsound from the speakers-making itunintelligible. It wasn't that the levelwas too low, because when we wentfrom nothing to something; the choirthen had a sense of direction ofwhere the sound was coming from.

Figure 5.Sweepable controlpermits you tomove the centerfrequencies around.

My point of reference to equalizationis to make sure that you are workingon the cure, instead of a symptom.Make sure your mic placement isright. Make sure you don't have toomany mic's open at one time. Andyou better make sure your speakerplacement is proven correct; or youwill make things even worse byequalizing.

SUITING EQ TO THE NEEDSound systems are used for differ-

ent purposes, so equalization curvesshould suit the need. For example,my friends who go to a Church of

Christ service don't believe thatmusical instruments should be usedin worship, so they would require adifferent curve than let's say; an As-semblies of God service, who usuallyhave an aggressive music programin comparison. The curve at theChurch of Christ would look like Fig-ure 7a, while the Assemblies of GodChurch would use the curve in Fig-ure 7b. Some of you are probablysaying, "I thought you wanted a flatfrequency response." Well, that istrue for the most part. In a systemdesigned for music reproduction; thesound would come across too brightfor the average listener and wouldalso cause a sibilence problem in asystem designed for speech. There-fore, you would equalize flat with apreferred listening curve which issimilar to Figure 7c. I should also addat this point that you do not wantequalization to compensate for hear-ing loss because this varies widelywith each individual.

EQ EQUIPMENTTo equalize a sound system you

will need at least, a pink noise gener-ato4 real time analyzer, and a soundpressure level meter. If you don'thave these tools, then you have nobusiness trying to equalize a soundsystem; and you should leave it to aqualified sound contractor electro-acoustic consultant or technician.

Before turning on your pink noiseto start tuning, we have to have allthe sound system devices set, includ-ing our crossover. First, place theRTA's microphone in front of thespeaker array in the seating area.Next, turn on the pink noise, andstarting with the low frequencies,

Figure 6. Graphic equalizers have fixed frequencies and fixed "Q" and they work with the boost/cut charac-teristics shown.

Allfrequencies

@ +12

+12

0rnrn

UL

All12 frequencies-0

@ -12

12

toto 31.5 63 125 250 500 1K 2K 4K 8K 16K

±2dB from 1000Hz

(0Variations below 1000Hz

(A)(sometimes not equalizable)

-0-J0 -CI)

(B)

-0

(C)

c)

Rolloff -3dB/octaveabove 5kHz

±2cB 200Hz to 1kHz

Rolloff -3dB/octaveabove 1kHz

7'Select rolloff appropriate to loudspeakers used

±2dB 100Hz to 8kHz

Select rolloff appropriate toloudspeakers used

Rolloff -3dB to-6dB/octave above

8kHz

1±2dB above 80Hz

ctappropriate

rolloffco appropriate to(D) loudspeakers usedliiiiitiiIiiiiili .1 illi i i i

I

i

40 I 100 I 250 I 630 I 1.6K 4K I 10K63 160 400 1K 2.5K 6.3K 16K

Third frequency (Hz)

Rolloff -3dB/octave

Maintain curve to12.5kHz

Figure 7. Differ-ent equalizationcan be set fordifferent condi-tions. Note thatcontrols are notnecessarily set"flat."

work your way up the spectrum andflatten the response. Now, add thepreferred listening curve that wcrksbest for your application.

Finally, turn off your pink noiseand turn on a microphone that youwould normally use in a service (usu-ally the pulpit works best here), andslowly bring up the gain until you getfeedback. Cut the f:equency givingyou problems about -2 dB, and alsocut the adjacent frequencies about -1 dB. Repeat this until no onefrequency stands out. When youreach the point that you hear multi-ple feedback frequencies; you willstart to work against yourself if youcontinue to try to notch feedback.It's time to plug in the CD player andtake a listen and make your finaldecision on your tuning job. Some-times you will have to make minoradjustments on the overall curve tomake it just right.

I hope this overview has given youa better understanding of how andwhy we use equalization in churchaudio applications. In our next seg-ment, we are going to be looking atmulti -track recording, along with aninside view of a church takingadvantage of m Ati-track tech-nology.

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RANDY HOFFNER

F4441(44,7

New Zealand: Home Of The World's Newest Television Network G'Day, Mate! I've recently re-

turned from New Zealand, where Ihad the privilege of helping to launchTV3, New Zealand's first private tel-evision service. Although New Zea-land has had privately -owned radiostations for several years, this marksthe first competition ever for thegovernment -owned television serv-ices. It was a unique experience tospend five weeks among the"Kiwis," as New Zealanders callthemselves. I enjoyed getting toknow the people, the country, and itstelevision broadcasting structure,which differs greatly from our own.

GEOGRAPHY ANDBACKGROUND

New Zealand is a country that con-sists primarily of two islands, whichalthough narrow, span a total top -to -bottom length of about 1,000 miles.In land area, the country is about thesize of England. Cook Strait, thetwelve -mile -wide waterway whichdivides the two islands, creates a

wind tunnel between them that hasearned the capital city of Wellington,located at the bottom of the North Is-land, the title of "The Windiest Capi-tal City in the World."

New Zealand is located about1,200 miles southeast of Australia,its closest neighbor. The northernsection of the North Island enjoys analmost sub -tropical climate. This isthe site of Auckland, the country'slargest city, comprising nearly athird of its population. The southerntip of the South Island, at about 47degrees southern latitude, is the sec-ond -closest land mass to Antarctica,after the lower tip of South America.Although the South Island's climateis colder than that of the North Is-land, the fact that these are geo-graphically isolated islands giveseven the South Island a much moremoderate climate than might be ex-pected by its latitude.

New Zealand is certainly one of themost beautiful countries in theworld. It is located on a volcanic

Figure 1. Downtown Auckland, with an extinct volcano crater in the fore-ground. Ridges visible on the hillside are artifacts from terrace farmingby Maoris in past centuries.

Cf.)if)

ridge, and extinct and dormant vol-canoes abound. The most prominentlandmark in the Auckland harbor isthe island of Rangitoto, a dormantvolcano that last erupted about 300years ago. Volcanic activity results inhot springs at Rotorua, in the centralNorth Island, that is a favorite at-traction for both locals and tourists.The plant life in the north includespalm trees, giant tree ferns, and theancient giant kaurie trees. Auck-land's climate, its coastal location,and its large complement of beauti-ful and uncrowded beaches havenurtured an outdoor lifestyle withemphasis on such activities as "bar-bies" and boating. The South Islandis home to the Southern Alps, wheresome of the world's best skiing is en-joyed, and a large section of the westcoast of the South Island is coveredwith a rain forest.

The grassy, mountainous terrainsupports a vast livestock farming in-dustry, with sheep and dairy cattlebeing raised in abundance. New Zea-land boasts that it is home to 70 mil-lion sheep, but I have it on goodauthority that sheep under one -year -of -age are not included in that countand that in fact, at certain times ofthe yea4 there are over 100 millionsheep in this country of 3.5 millionpeople. It is no surprise then that ag-riculture, and in particular sheepand sheep products, are New Zea-land's principal exports.

The indigenous population of NewZealand is the Maori people. TheMaoris are a Polynesian people thatcame to New Zealand in canoesabout 400 years ago. Englishcolonists arrived in the nineteenthcentury.

A treaty was signed in 1840, be-tween the Maori people and the Eng-lish explorers, that permitted peace-ful colonization to take place. 1990 isa year of celebration to com-memorate the 150th year of thattreaty. An amiable pattern of

cooperative living and inter-marriage between New Zealandersof English descent and the Maorishas been the norm since; with recentgenerations embracing a strong sen-timent for the preservation of theMaori heritage and culture.

TVNZFrom 1962, which marked the

beginning of television broadcastingin New Zealand, until November 26,1989, the Kiwis had only the two net-works of the state-owned televisionservice to watch. This service was apart of the Broadcasting Corpora-tion of New Zealand (BCNZ). A fewyears ago, BCNZ was reorganized,and two government -owned cor-porations, Television New Zealand(TVNZ), and Broadcast Com-munications Limited (BCL) werecreated.

These are expected to function asbusinesses competing in the com-mercial marketplace. Concurrently,the groundwork was laid to open tel-evision broadcasting to private enti-ties. TVNZ consists of the two televi-sion networks TV1 and TV2, whichnow sell commercials to supportthemselves. BCL owns and operatesthe transmission facilities used byTVNZ, and contracts to performservices for both TVNZ and outsideentities. Several TV3 transmissionfacilities share antennas withTVNZ, and BCL has constructedand maintains some of TV3's trans-mission facilities as well.

TV3On the evening of November 26,

1989, the long-awaited competitorto TVNZ emerged when TV3 wenton -air. TV3's debut was preceded bya continuous one -and -a -half -weektransmission of their test pattern,accompanied by promotional activi-ties with local radio broadcastersand newspapers, to increase aware-ness of TV3's presence (although it isdifficult to imagine that anyone inthe country was unaware that TV3was coming). This test patternbroadcast enabled the local populaceto tune in TV3 on their sets. NewZealand television receivers are sim-ilar to those used in Europe, beingtailored for a situation where therehave traditionally been only a fewtelevision services offered, as op-posed to our all -channel, cable -readysets in the United States which caterfor our multiplicity of outlets. Here

in the U.S., if we wish to view a localTV station on channel 4; we simplyswitch the channel selector to"4",and there it is. Older New Zea-land receivers have five or six pro-gram selection buttons-each ofwhich must be preset to the desiredtelevision channel. The electronic -tuning counterpart of these button -type sets has a number of "pro-grams" which may be preset to anybroadcasting channel (frequency al-location) that the viewer wishes.Like TV1 and TV2, the channel orfrequency allocation used by TV3varies depending on the geographi-cal area, but that channel would notappear on a "program" or a buttonon a viewer's set, because there wasno reason to have tuned it in before.So the viewer, or a serviceman, mustpreset a "program" to the appro-priate channel in order to view thenew service.

TRANSMISSIONThe structure of television broad-

casting is completely different inNew Zealand from what we know ofin the United States. TV3 is a net-work that will cover the entirecountry when it is completed, and atits inception serves about 75 percentof the population. The network orig-inates a single program at its Auck-land studios, and this program islinked throughout the North andSouth Islands to its transmitting sta-tions, all owned and operated byTV3. United States television broad-

casting networks are very complex,and each actually consists of a num-ber of networks, but New Zealand'sTV3 is actually somewhat like a tele-vision station with seven transmit-ting sites instead of one. Even time -shifting by the network isunnecessary, because although NewZealand is about a thousand mileslong, it is so slender that it fallscompletely within one time zone.

TRANSMITTER SITESOn launch day, the TV3 network

consisted of seven transmitter sites,scattered around the North andSouth Islands to cover the majorpopulation centers. There will be ad-ditional transmitting sites addedover the next two years, beginning tocome on-line in January, 1990. Thehigh -power transmitting stationswill be augmented with a number oflow -power repeaters to fill in cover-age gaps in the mountainous terrain.The network headquarters is inAuckland, the country's largest city,and of course, there is a transmittersite serving Auckland. There are alsotransmitter sites in the Hamil-ton/Cambridge area, the WesternBay of Plenty, Palmerston North,and Wellington on the North Island:all the transmitters are co -sited withTVNZ transmission facilities. Theprogram audio and video signals arecarried on a microwave studio -transmitter link from the TV3studio to the Auckland transmitter,and via a digital linking network

Figure 2. The satellite earth station atop Waiatarua, site of the transmit-ting tower that serves Auckland.

01-.I

co

I

Figure 3. TV3's new tower on Ruru Hill, serving the HamiltonlCani-bridge area of the North Island.

supplied by New Zealand Telecom tothe other transmitter sites. Thetransmitters are all controlled fromthe Auckland studios using a singlePC to control and meter all sevensites simultaneously via a two-waydata stream on a network consistingof STL subcarriers, UHF radio links,and a Telecom digital circuit. Themulti -site control/metering systemis expandable, and is expected to ulti-mately control twenty sites.

CHANNELSUntil recently, there were only ten

VHF television channel allocationsin New Zealand, channel 1 throughchannel 10 (yes, there really is achannel 1). These VHF channels areeach 7 MHz wide conforming toStandard "B", and PAL video isbroadcast on them. Channel 1 isquite low in frequency, extendingfrom 44 to 51 MHz, and is used onlyfor translator service in a few areas.The frequencies occupied by theNew Zealand VHF channels differsfrom those occupied by correspond-ing channels in the United States,which is not surprising consideringthat each channel is 7 MHz wide asopposed to our 6 MHz channels. Al-though the frequency blocks oc-cupied by many "B" Standard VHFstations in Europe are largely thesame as those in New Zealand, thechannel numbers assigned to thoseblocks are not the same; so while aEuropean television receiver willwork in New Zealand, the channel

numbers will be different. As an ex-ample, in Auckland, TV3 is on chan-nel 7, which ranges from 195 to 202MHz. That spectrum is occupied byportions of channel 10 and channel11 in the U.S., and in Europe corre-sponds to channel 8. Channel 11 wasrecently added to the New ZealandVHF TV spectrum. The spectrum al-located to channel 11 was formerlyused by the New Zealand military.There is a UHF television spectrumallocation in New Zealand, althoughas of yet, there is no UHF service.

STEREO TVTelevision stereo is available in

New Zealand, using the BBC -developed NICAM 728 digital stereosystem. The NICAM (Near Instan-taneous compression And Multi-plexing) 728 (kilobits per seconddata rate) system permits the trans-mission of two channels of audio,either stereo or two completelydifferent programs; on a second,low -amplitude aural carrier locatedjust above the monaural FM carrier.

This system has a 32 kHz samplerate providing 15 kHz audio band-width, and initial 14 -bit resolutioncompressed to 11 bits. It is interest-ing to note that this is the only televi-sion stereo transmission system inuse worldwide that does not rely onsome form of sum -and -differencematrixing. The monaural signal istransmitted completely separatelyfrom the discrete left and right chan-nel stereo signal.

This system would thus afford theopportunity, if desired, to transmitseparate mono and stereo mixes, al-though to the best of my knowledge,that is not done in practice. Theusual technique is to send discretetwo -channel stereo to the transmit-ter sites, at which point a sum of leftand right is generated to modulatethe monaural carrier.

Atypically, the Kiwis did not followthe lead of their closest neighbor,Australia, on TV stereo, as theAustralians use the German analogstereo transmission system, inwhich the sum of left and right chan-nels appears on the main aural car-rier and the left channel only modu-lates a second FM carrier.

This is a type of matrixed stereosystem, albeit a far different onefrom our own. New Zealanders can-not buy a stereo television receiveron a visit to Australia with the expec-tation that it will receive stereo backhome.

FACILITIESTV3 headquarters features large

studios and state-of-the-art produc-tion, editing, and distribution facili-ties. On -air playback is from one -inch and D-2 composite digital videotape and commercial and news seg-ments are aired from half -inch tapecassettes using a robotic ea-ssettehandling system. Additionally, TV3has a studio in the capital city ofWellington. There are also "itinerantcontribution" facilities for newsfeeds at several locations around thecountry. These are unattendedphone booth -like facilities where areporter may plug in to a Telecomlink and feed news pieces back toAuckland. Like cable television,satellite news -gathering has not yetarrived in New Zealand. TV3 does,however, have access to world satel-lite news services, including NBCSkycom and Visnews.

CONCLUSIONThe long-awaited launch of TV3 is

now history, and the world's newesttelevision network is providing abrand new television service to thepeople of New Zealand. It was an ex-citing project to be involved in, and Ihope you have found reading aboutNew Zealand and its televisionbroadcasting system interesting.

LEN FELDMAN

Shure Model 1200 Powermixer Amplifier

The Model 1200 is shown atop two optional Model 3200 speakers.

GENERAL INFORMATION The Model 1200 Powermixer, by Shure Brothers In-

corporated, is one component of that company'sAudiomaster System. Other elements of the system in-clude the Model 3200 Loudspeakei the Model A 1200MXExpansion Module and the Model A 1200C PortableCase. The Model 1200 Powermixer tested for this reportis rack -mountable or portable. It is a high -power, 6 -inputmixer amplifier, expandable to 8 or 10 inputs. Inputs ac -

Figure 1. Frequency response of the ShureAudiomaster 1200.

Amplitude (dB) Frequency (Hz): Shure Audiomaster 1288

sAlese

4.0000

3.6800

2.8680

Lime

0.8

Lem,

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3.800

4.088

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108 1k 184 28k

cept both high and low impedance microphones as wellas amplified instruments or other high level sources.Two of the six available inputs can be used for high (linelevel) inputs or for microphone inputs, while the remain-ing four inputs are intended only for microphone input.High and low impedance inputs may be used simul-taneously. Individual input attenuation controls, withoverload indicators, are continuously adjustable to pre-vent input overload. The unit has built-in reverberation

Figure 2. The range of bass and treble controls ver-sus frequency.

Bass and Trek!. EQmem

15.808

16.000

5.6808

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Figure 3(A). Harmonic distorion plus noise versusfrequency at rated output of 120 W 'channel at 8 ohms.

with individual channel and overall level adjustments.Other effects devices or an equalizer can be easily con-nected via a post -master control program loop. A limiterin the power amp section prevents overload distortionover a wide input signal range.

Pre -volume monitor "send" controls and a pre -mastervolume Tape Output provide extra flexibility in perform-ance or recording applications. The control panel (about

Figure 3(B). Harmonic distorion plus noise versusfrequency at rated output of 200 Wlchannel at 4 ohms.

TIO t Noise 17)

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which more detail in a moment) is sensibly engineeredwith color -coded knobs that prevent errors during ad-justment. LED indicators give instant visual notice ofoverload and operating status. Shure tells us that theunit was designed for churches, schools, clubs, civic andbusiness organizations and small performing groups.

Figure 4(A). Harmonic distortion plus noise versuspower output per channel (8 -ohm loads). Best curveis 1 kHz; next best is 20 kHz; poorest is for 20 Hz.

Distortion t Noise (el vs Power Output/Channel: Shure Audi...ester 12805

cp 0.018d 2 18

1,

91

188 288

Distortion r Noisy 1,1 vs P mr 0 1pu tdChe .1' Shur. Au.l.5

0.010z 10

1280 411.

PI

188 308

Figure 4(B ). Harmonic distortion plus noise versuspower output per channel (4 -ohm loads). Best curveis 1 kHz; next best is 20 kHz; poorest is for 20 Hz.

The unit is fairly lightweight and compact, as such pro-ducts go, measuring only 7 -inches in height and weigh-ing only about 27 pounds.

CONTROL LAYOUTAll six input modules, positioned vertically along the

left section of the Model 1200, have identical, coloredcontrol knobs. Starting at the top, a "Monitor" knob con-trols channel monitor "Send" independently of channelvolume control. The user would adjust this knob whenusing a monitor system or for auxiliary or tape recordingmix. Next, a reverberation control determines theamount of reverberation added to each channel. Concen-trically mounted bass and treble equalization knobscome next. Below the EQ knobs is an input overload in-dicator. The input attenuator below that indicator, hasan attenuation range from 0 dB (no attenuation) to -30dB, with calibration marks at 0, -6, -12, -24 and -30 dB.Finally, the channel volume control allows individualsetting of channel input for the desired signal mix. Whena channel is unused, this volume control is set fully coun-terclockwise.

Over at the right side of the panel is a master controlmodule. Its uppermost control is a monitor mastervolume knob. Below that is a "Reverb Return" knob thatcontrols the reverb mix level to program mix. Dual con-centrically mounted bass and treble controls alter tonalresponse of the monitor mix signal. A power amplifierlimiter in/out switch, when in the "in" position, preventsoverload distortion at the speaker and headphone out-puts by not allowing the power amplifier to be over -

Figure 5. Spectrum analysis of 120 W. A 1 kHz sig-nal using an 8 -ohm load.

SPECINUM ANALYSIS OF 1261. 1 ItHs SIGNAL, SHURE AUDIO1AITE0 12800.0

-20.50

-15.08

-68.88

00.08

tea 8

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Figure 6(A). Spectrum analysis of residual noise,500 mV input, 1 watt output reference level.

driven. A master volume control adjusts overall level ofthe mixed signal at the Program Mix output, SpeakerOutput, and Headphones Output. Further down alongthis master module are a headphone volume control anda standard 1/4 -inch headphone jack that accepts 4- to4000 -ohm mono or stereo headphones.

The main power switch is located at the lower righthand corner of the front panel. To its left is a green LEDthat lights up when power is turned on. A yellow LEDabove it lights up whenever signal is present at the am-plifier output. A red LED mounted still higher on thepanel lights just before clipping occurs or, if the limiter isturned on, at the onset of limiting. Another red LEDflashes to warn of overload or unsafe operating condi-tions. It lights continuously if the power amp shuts downbecause of overheating, or because of an abnormalspeaker load, such as a short circuit.

The rear panel of the Model 1200 is equipped with low -impedance XLR balanced input connectors as well as 1/4 -inch high -impedance unbalanced phone jacks for each ofits six input channels. Above the phone jacks associatedwith Channels 1 and 2 are Mic/Aux switches that permitthese channels to be used either for microphones or forhigh level inputs. Blanks in the rear panel accept Shure'sModel A1200MX Input expansion modules, each con-taining two channels, so you can add a total of four moreinputs. The rear panel also houses a Monitor Outputjack, a Tape Output Jack to Speaker Output jacks, Pro-gram Mix Output and Power Amplifier Input jacks(these two comprise the external device loop facility) anda Reverb Defeat jack.

Figure 6(B). Spectrum analysis of residual noise,typical control settings at midpoint, referred to 120watts output.

Spectrun Analysis of hesidual Noise (dB) vc Frequency No): Shure 12011-50.00

F2ip

-66.86,

-70.66

-06.60

-98.88

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Jlo

11 105 261

All of these jacks, including the speaker output jacksare 1/4 -inch phone plug type jacks. We found it a bit un-usual that Shure chose to use phone jacks of this type foraccessing the amplifier's speaker outputs, but realizedthat if you were to purchase the Shure Model 3200 loud-speakers that are an integral part of the ShureAudiomaster system, these too would be fitted with suchjacks, and connection would be made using an accessorycable (A5OSC) fitted with phone plugs at each end. Twosuch cables were supplied by Shure for our tests, as was acable fitted with XLR connectors at each end. An un-switched AC convenience outlet and a phantom poweron/off switch completes the rear panel layout. The phan-tom power switch, if turned on, will supply 24 volts of DCto condenser microphones connected to any of the in-puts.

LABORATORY MEASUREMENTSFigure 1 shows the frequency response of the amplifier,

when fed with a 50 mV (high level) signal via one of thebalanced inputs. Published specification were easily met,since Shure quotes response as extending from 40 Hz to20 kHz, +1, -3 dB and our test sample clearly did betterthan that, with bass response off by only -2.0 dB at 20Hz.

Figure 2 shows the maximum boost and cut range ofthe EQ controls for each channel. Results were almostexactly the ± 10 dB at 100 Hz and 10 kHz claimed byShure in their published specifications.

Figure 3A is a plot of total harmonic distortion plusnoise versus frequency, with the amplifier driving an 8 -ohm load and with power output regulated to maintain aconstant 120 watts output at all frequencies shown. At 1kHz, THD plus noise measured 0.58 percent, while at nofrequency did THD plus noise exceed the 1 percent rat-ing assigned by Shure for a 1 kHz test signal at 120watts, into an 8 ohm load. The same test was repeatedusing a 4 -ohm load. Results, shown in Figure 3B, werenot quite as good. While Shure claims a THD with thisload of 1 percent for 200 watts output, we measuredcloser to 2 percent at that power output level.

Figures 4A and 4B show how THD plus noise varied asa function of power output using an 8 -ohm load (Figure4A) and a 4 -ohm load (Figure 4B). Notice that highestdistortion was obtained for a test frequency of 20 Hz ineach east,. while, as expected, lowest distortion occurredusing the mid -frequency test signal of 1 kHz.

We wanted to separate actual THD from residual noisefor at least a 1 kHz test signal. To do this, we employedthe spectrum analysis capabilities of our test equipment,with which we analyzed the spectral content of a 1 kHztest signal at an output level of 120 watts, into an 8 -ohmload. The chief component of distortion seen in the graphof Figure 5 is, as expected, a third harmonic of the fun-damental 1 kHz test signal. This harmonic distortioncomponent was some 70 dB below the reference outputlevel. That corresponds to a 3rd harmonic distortion per-centage of around 0.03 percent.

Shure quotes signal-to-noise ratio referred to ratedoutput as -80 dB "with typical control settings." We'renot quite sure just where those control settings werewhen they made their measurements, but for every kindof S/N measurement we made, results were actuallymuch better than that. For example, using the amplifiermeasurement standard developed by the old IHF and

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Figure 7. A block diagram of the Shure Audiomaster 1200.

now sanctioned by the EIA, we measured S/N of 98.35dB referred to an input level of 500 mV with input at-tenuator and volume controls adjusted to deliver 1 wattoutput. We also analyzed the spectral content of thisnoise, using the same reference input and output levels,with results shown in Figure 6A. The chief "noise" con-tribution was actually power supply hum, with a noisepeak clearly visible at 60 Hz and smaller peaks noticea-ble at 120 Hz and 180 Hz.

This analysis was repeated with controls set to theirmid -points and with dB readings referenced to 120 wattsof output (Figure 6B). The fundamental shape of thecurve remained the same (with the same power -supplyrelated peaks visible), but of course, the dB readings ofS/N at the various frequencies were now much higher be-cause of the higher output reference level.

Finally, we measured SMPTE-IM distortion at theequivalent of 120 watts (for 8 -ohm load conditions) and200 watts (for 4 -ohm load conditions). The test signalconsisted of 60 Hz and 7000 Hz sine wave signals com-bined in a 4:1 amplitude ratio. The two readings ob-tained were 0.116 percent and 0.558 percentrespectively.

CONCLUSIONSTo fully appreciate the versatility of this ampli-

fier/mixer; you should not only spend some time using it,but should also study the signal flow -path as illustratedin the block diagram of the Model 1200: found in theowner's manual and reproduced here as Figure 7. ShureBrothers are past masters at this sort of equipment,having been in the business of sound reinforcement pro-ducts for as long as we can remember. It occurred to meas I was using the equipment that a compact all -in -onemixer amplifier such as this could easily replace some

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multi -component systems I have encountered re-oently-systems that take up many times the space ofthe Model 1200 and don't offer nearly as many featuresor as much flexibility.

As an experiment, I set up a system consisting of acouple of high level inputs (a mono AM radio feed and aTV sound feed) to the first two channel inputs (havingset them for high-level input) and connected a couple ofmicrophones to channels 3 and 4. In almost no time flat Ihad a good balance for all of these inputs and, after a bitof experimentation, the small amount of reverb that Iadded to the mic channels made my ' amateur" singinggroup sound a lot better than they had a right to sound. Abit of bass boost on one of the mic charnels improved theoverall sound quality of my "hobbyist" announcer'svoice. While all of these experiments with the ShureModel 1200 Powermixer were of an unofficial nature, letme assure you that the equipment itself is very pro-fessional in every sense of that word. Even the colors ofthe knobs made sense and those colors will be especiallyhelpful if you have to work as a mix ?r in conditions ofsubdued lighting where even the clear nomenclaturefound on the front panel of this mixer/amplifier may notbe readable. All in all, Shure Brothers Incorporated havecreated the kind of product that I would have expectedfrom them-nothing short of a superb one.

Editor's note: Shure AUDIOMASTER systems,of which this unit is a part, inc_ude speaker sys-tems, microphones, cables, etc. ?or example, oneof the matching speakers, Model 3200, are$470.00 each.For complete information on thesesystems circle 75 on this issue'; Reader ServiceCard.

0cmcm

SPECIFICATION

VITAL STATISTICS

MFR'S CLAIM db MEASURED

Frequency Response ±3 dB,Power Output, 1 kHz, 1% THD

Low & Hi Freq EQInput Sensitivity (full output)Balance Lo ZHi ZAuxPA InputVoltage Gain R 1 kHzLo Z (Speaker)*Hi Z (Speaker)AUX (Speaker)PA (Speaker)Output Clipping LevelSpeakerMonitorProgram MixPhonesTapeImpedance (Inputs)Lo Z MicHi Z MicAuxPAImpedance (Outputs)MonitorProgram MixTapePhonesSpeakerSignal -to -Noise RatioPower RequirementsDimensions (HxWxD, in.)Weight

40 Hz to 20 kHz200 W @ 4 ohms120 W @ 8 ohms-±-10 dB @ 100 & 10 kHz

0.5 mV6.3 mV50 mV0 dBV (1 V)

95 dB73 dB55 dB29 dB

28 V7.9 V7.9 V6.3 V7.9 V

1 kohm130 kohm50 kohms50 kohms

2.4 kohms2.4 kohms2.4 kohms430 ohms

80 dB120 VAC, 50/60 Hz, 420 Watts

7-1/2 X 19 X 13-1/227 lbs.

+0.8,-0.5 dB185 W @ 4 ohms125 W @ 8 ohmsConfirmed

0.48 mV6.0 mVConfirmedConfirmed

96 dBConfirmedConfirmedConfirmed

28.2 V8.0 V8.0 V6.5 V8.0 V

Use with 75 to 600 ohmsUse with 100 k or lessUse with 10k or lessUse with 10k or less

Use with 2 k or moreUse with 2 k or moreUse with 2 k or moreUse with 4 ohms or moreUse 4 ohms or more98.3 dBConfirmedConfirmedConfirmed

--,E Price: $ 1,200.00aa.E *Program2 mix 30 dB less gain than speaker out, monitor out is 24 dB less than speaker out,g phones out is 13 dB less than speaker out and tape out is 44 dB less than speaker out.

v.1 -CD

brmagazine

serving: recording, broadcast and sound contracting fie'ds

AmplifiersIntroduction to the Charts

We've tried to make the charts of amplifiers as self-explanatory as possible, with slantingheadlines on each column that explain what we wanted to show you.

These charts represent entirely what each of the respective manufacturers have sent us into our (sometime repeated) requests. You will also see that there are numbers of

blank sections within the charts. If they don't have a specification available, we can't list it.But note that many do not have anything under the Features column. This column is where wehave invited each manufacturer to state, in as few words as possible, what is special about theproduct. You can safely assume, then, that when this column is blank, it is because themanufacturers told us nothing.

Note also that we ask for amplifier continuous power not only at the traditional 8 and 4 ohmresistive loads, but also at 2 ohms. As you know, when you parallel speakers, the load ishalved. Accordingly, in the real worlds of studio monitors and headphone lines, and the evenmore real world of performance and stadium systems, effective loads back to an amplifier canwell be 2 or 3 ohms. Since modern solid-state amplifiers can handle such loads su:cessfully, weask each manufacturer for this specification. Note that not all give it. It's, therefore, safe toassume that if it is missing, the amplifier may not be reliable at low loads.

Distortion at normal and full power ratings is also specified. While many amplifiers today canboast of almost vanishing distortion, remember that if you will be pushing an amplifier hardup against its rated power and beyond, distortion will then be rising rapidly. No audio productis really made to be abused, and amplifiers are no exception.

One group of important specifications deals with dimensions and weights. Amplifiers, particu-larly high -power ones, are not lightweights. A few racks can have weights adding up rapidly.

Finally, the price. What we have asked each manufacturer for is the suggested retail price.Different retail dealers establish their own.

On to the charts...

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ALTEC LANSING9442A 100 150 10- 10 .10 .10 .10 10- .89 5.25 32

50k 50k 19

-3 -3 14 75

1270C 2 220 400 20- 05 .05 .3 .1 7- .89 5.25 51.5

20k 33k 19

0.5 -3 15

1407A 1 75 75 20- 01 .01 .2 .1 10- .78 5.25 24.220k 30k 19

-3 -3 12.5

1415A 1 150 150 20- C1 .01 .2 .1 10- .78 5.25 30.8

20k 30k 19

-3 -3 12.5

2200A var 20- .5 .25 10- .61 7 70

15k 30k 19

0.5 -3 17.4

2204A 4 75 150 300 20- 5 .25 10- .78 5.25 31.5

(4ch) (2ch) (1 ch) 15k 30k 19

0.5 -3 16

9444A 2 200 300 10- 05 .05 .2 10- .81 5.25 39

70k 85k 19

-3 -3 12.75

ARX SYSTEMS -See our ad on page 2SS1200VC 2 400 600 10- .03 .05 10- 1.5 3.5 28

20k 20k 12

0.25 19

SS600VC 2 250 325 10- .03 .05 10- 1.5 3.5 22206 20k 12

0.25 19

ASHLY AUDIO, INC.FET-2000C 2 300 500 675 20- .004 .01 004 .01 20 1.7 5.25 60

20k 20k 19

16

FET1500C 2 200 300 31,0 20- .004 .01 .004 .01 20 1.7 3.5 42

20k 20k 19

16

FET1000C 2 120 190 225 20- .004 .01 .004 .01 20- 1.7 a 5 37

20k 20k 19

16

BGW SYSTEMS, INC.7500T 2 200 250 20- .05 3- 1.22 5.25 36

20k 100k 17.510.5

SPA -1 2 250 400 600 20- 7.05 5.25 41

20k 19

13.7

SPA -3 2 250 400 20- 7.05 5.25 43

20k 19

13.7

750FG 2 280 450 20- .01 .06 20- 1.5 7 5520k 20k 17.3

12.9

GTA 2 350 600 900 20- 03 20- 1.48 7 72

20k 20k 17.5145

GTB 2 275 400 BOO 20- .03 .1 20- 1.48 5.25 50

20k 20k 19

13

85001 2 300 450 850 20- .05 20- 1.6 5.25 50

20k 20k 19

138BRYSTON (BRYSTON VERMONT, LTD)

2 50 100 20- .01 .01 .01 20- 0.75 1 75 18

50k 50k 19

10

2 100 200 20- .01 .01 01 20- 1 5.25 35

50k 50k 19

9

4 2 250 400 20- 01 01 C1 01 20 1 525 41

50k 50k 19

105

6B 2 500 BOO 500 20- 01 .01 01 .01 20- 0.75 5.25 50

50k 50k 19

135

270 2 50 100 20- 01 .01 01 .01 20 0.75 3.65 20

50k 50k 19

10

370 2 100 20- 01 .01 01 .01 20- 0.75 5.25 35

50k 50k 19

9

2-B 2 250 20- 01 .01 01 .01 20- 0.75 5.25 5050k 50k 19

13.5

5770.00 Choice of XLR, and ter -urinal inputs, accesory octal socket,peak and protection LEDs.

51850 00 Choice of XLR, 1/4 -in. and ter -mina) inputs, peak and protectionLEDs, two -speed fan cooling.

5580 00 Includes XLR (male and female),phono and terminal inputs, directand X -former output, protection.

5698 00 XLR (male and female), phono andterminal inputs, driver protec-tion relay, convection cooling.

55100 00 Eight 75W power amp modules thatcan be configured for numerousoutput combinations up to 600W.

$1750.00 Four 8 ohm/75W power outputs thatcan be paralleled and/or bridged,X -former isolated inputs.

$958 00 Electronically balanced XLR orterminal inputs, octal socket,peak and protection LEDs.

$1349.00 Conventional power supply for driveoutput stages.

5999.00 As Above.

5999.99 Barrier strip inputs,MOSFET,ULlisted. FT2000M same with peakreading meters -51059.99.

5799.99 Barrier strip inputs,MOSFET,ULlisted. FT1500M same with peakreading meters,XLRs-5859.99.

5659.99 Barrier strip inputs,MOSFET,ULlisted. FT1000M same with peakreading meters,XLRs-5699.99.

Modular construction barrier -strip term.,plug-in crossover.

Signal processing subwoofer ampparametric EQ.

Signal processing amplifier,active,balanced inputs.

Low feedback design, available ina studio version.

Grand touring amp, solid state DCspeaker protection.

Accepts 2 BGW crossover cardsfor bi- or tri-amping.

Cost-effective version of GTBdesigned for fixed installation.

5725.00 Modular design, gold plated contacts,bridgeable to mono.



51895 00 Modular design, gold plated contacts,bridgeable to mono.

$500 00 Modular design, gold plated contacts,bridgeable to mono, 70V unit.

5695 00 Modular design, gold plated contacts.bridgeable to mono, 70V unit.

$1050.00 Modular design, gold plated contacts,bridgeable to mono, 70V unit.

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CARVER CORPORATIONMI20 2

M300

M600

M900

MI200

M1250

2

2

2

2

2

45

110

200

350

450

350

60 90 20-20k

150 180 20-20k

300

450

20-

20k20-

20k

41

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.5 20- 1.520k05

.5 20- 1.520k0520- 1.5

20k5 S 20- 1.5

20k

600 20- .5 .5 20- 1.520k 20k

0 1450 20- 20- 1.5

20k 201.

01CARVIN CORPORA' ioNFET 301 2 100 200

FET 400

FET 900

AUDIOCREST4801

6001

CC151

CC301

7001

8001

FA -901

FA -2401

CROWNMacroTech 600

MacroTech 2400

MacroTech 1200

MicroTech 600

PB2

PS -200

PS -400

CT -1600

2

2

2

2

2

1111111.12

2

2

100

200

400

525

200

360

560

750

280

350

300 5- .005 .1 20- 1

80k 20605

200 5- 006 .1 20- 1

80k 20k300 450 5- 006.1 20- 1

80k 20k.05

575 750 20- 015 015 .025 20- 1.120k 201.

700 880 20- 015 .015 025 .025 20- 1.220k 20k

325 650 20- 015 .015 .025 .025 41 20- .18720k affil 201:

540 20- 015 .015 026 20- 1.220k 20!c

810 850 20- 01 .0 06 20 1.420k 20k

1225 1400 20- 015 .015 O6 20 1.7520k 20.c

375 500 20- 015 .015 026 20 .77520k

600 770 20- 015 .015 .77520k

INTERNATIONAL -See our ad on page 32 235 325 340 35k 05 .05 I .001 .77

20k0.1

.001525 800 1200 20- 111 .0620k

20-20k0.1

.77

320 085 600 20- .06 .05 .001 .05 20- .7720k 20k

4 0.1235 340 410 20- .06 .05 .05 .05 20- .77

20k 20k0.1

320 400 20- .06 1.05 .05 .05 20- .7720k 20k

0.1100 170 .01 1.001 I O6 DC -

35k 20k0.1

320 400 DC- Ili .01 x.01 .001 0- 1.7635k Imo, 20k

0.1540 875 20- .05 06 20- .77

20k 1. 20k0.1

7- .03 .77

pELECTRO-VOL=, INC.AP2600 200 300

AP2300

85k

100 190 7- .03 iii I.7785k

1.75 13 5499.00 XLR-barrier strip i 'puts, headphone19

13.5jack,clip indicators.

1.75 13 5499.00 XLR-barrier strip ilputs, headphone19 jack,clip indicators.13.5

3.5 13 5499.00 XLR-barrier strip inputs, headphone19 jack,led power in licators.1.75 13 5649.00 XLR-barrier strip nputs, headpho19 jack,led power in iicators.11.563.5 21 51249 00 XLR-barrier strip nputs, headphone.19

10.833.5 11 51450 00 XLR-barrier strip nputs, headphone1910 75

jack,led power in Jicators,cooling fan.

jack,led power in dicators,cooling tan.

5 25 26 5379 00 MOSFET technol)gy, speaker pro -19 tion, XLR AND r, -in. connectors.12

5.25 29 499 00 MOSFET technol )gy, speaker pro -19 tion,bridgeable,c ip LEDs .05105 25 35 5669 00 Same features ar the FET 400,19 yet has 900 watt: total output.10

3.5 48 51589 00 Front panel light.,active signal19 clip limit,load relays.15

3.5 51.5 52189 00 As Above.19

15

5.25 48 S118900 As above, can feed 70V19

14

5.25 50.5 51989.00 As above, also available as 70V19 vesion for 51389 00.13

3.5 Front panel light;, active signal19 clip limit,load relays.15

a 5 As above,can fe rd 70V.19

13

3519

13

3519

13

49.5 52589 00

80 53189 00

33 5879 00

55 51769 00

Front panel light ssignal clip limitdc -thermal proteztion:clip limit,loadrelays,can feed 'OV line.As FA901 above

3.5 39.6 51295 00 Chassis ground -lift switch,discrete19 power supplies, nono bridging, two18 input sensitivity ;ettings.3.5 67.8 51995 00 As above.19

16

3 5 44 51295 OC As above.19

16

3.5 37 5995.00 As above19

16

3.5 32 51045.00 Full protection circuitry,bridge and19 parallel mono,fc rced air cooling,dual16 input sensitivity.1.3 35 5819 00 Ultra low distort on,chassis ground19 lift jumperpassi re cooling.proof-of-10 2 performance in; icators.7 54 51259 00 As PS200 abov19

1027 61 51880 00 For sound contr actors,8-ohm or 70V19 constant voltage lines.many Micro16 Tech features.

525 39 5999 0019

1275525 39 56416519

1275 -

Available with precision steppedattenuators as node! AP2600SA.

Same as above CO

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c ,p o s,foc,,, 0 .10,crts c\ c\ c. cle" cs,;00S \,05-\oe

co:le VS' "2'. 09- kGo,'\ 0.0\7' VCrt'e \- e. .ceP oeC")e.Cs seCs4 't,'Ce 410 9ce.'' ceeNs>'e5

.kscse ,e\ ce\ ''cs," ePts l's?"'s e &-*

HILL AUDIO -See our ad on page 20Lcaoo 2 120 200 20-

20k

,60" 0,0" ,,,Nt

.01

LC800 2 250 400 20- .01

20k

LC1200 2 350 600 20- .01

20k

ML200 1 120 200 20- .01

DX1000

DX1000A

DX2000

DX3000

2 375 600

2 500 800

2 375 600

2 375 600

20k

20-20k

20-20k

20-20k

20-20k

INDUSTRIAL RESEARCH PRODUCTS, INC.DH4020 2 100 140 20-

20k

INDUSTRIAL STRENGTH INDUSTRIESPA700 2 230 350 10-

30k

INNOVATIVE ELECTRONIC DESIGNS, INC.6208 1 200 20-

20k

6270 1

JBL PROFESSIO6210 1

6211

6215

6230

6260

6290

1

2

2

NAL40

40

35

75

150

PASO SOUND PP 1,

P4061

P4121

P4201

T5121

PEAVEY ELECT UNILCS -1200 2 350

CS -i000 2 300

CS -800 2 240

2 210DECA 528

45

150

300

600

S600

500

400

250

20-20k

20-20k-120-20k-120-20k-120-20k-1

20-20k-120-20k- 1

20-40k

20-40k

20-20k

20-20k

.1

.02

.02

.02

.02

02 .1

.1

1

1

.1 1

.1 1

20- 1 20 17 51249 00 XLR,binding post, 1/4-in.inputs,20k 19 5 -way central logic protection.

14.255

20- 1 24 3020k 19

-5 14.2520- 1 24 3520k 19

14.255

20- 1 24 2820k 14.255 19

2420- 1.55 3 3820k 19

12

2- 0- 1.55 3 4020k 19

5 12

20- 1.55 3 7520k 19

18

20- 1.55 3 8020k 19

- 5 18

20- 1

20k-1

$1399.00 As above

$1749.00 As Above

$1249.00 As Above, 100V line oufalsoML400mode1,250W,33 lbs, $1399.00.

$2199.00 XLR,'ci-in. phone inputs,binding postoutputs, LED output indicators.

52499 00 XLR,-in. phone inputs,binding postoutputs, LED output indicators.

$2799.00 XLR,1/4-in. phone inputs,binding postoutputs, LED output indicators.

$3099 00 XLR, v4 -in. phone inputs,binding postoutputs, LED output indicators.

1.75 13.5 $1042.00 100 kHz switching power supply,19 MOSFET high freq. output.14

1.23 5.25 3419

13.38

.9 6.1 2.42.1

12.7.9 6.1 2.38

2.1

12.7

8 6.58.52 75

$699.00

$783.00

$783.00

$310.00

20- 8 6.5 $345.0020k 8.5

2.7520- 1.1 1 75 10.5 $6850020k 19

9

5.25 26.3 $730.0019

11

7 44.5 $1045.00 Same features as above.19

11

7

19

14

20- 1.1

20k

20- 1.1

20k

20- 1.1

20k

Built-in electronic X -over, bal-anced XLR inputs, mono bridging,protection, automatic fan cooling.

Class D (switching mode) designcard type, greater than 80% ef-ficiency at full output.200 watts into 25 ohms or 70.7v,all specs at 25 ohm load. Bothamps have balanced outputs.

Converts 4400 series or any other8 -ohm monitor into self-contain-ed power system.Same as above and also includesactive balanced inputs, but withmic/line selector switch.Active balanced bridging inputcircuitry, rear -panel switch forbridge/dual mono or stereo.Same features as above.

63 $1570.00 Same as above yet also includesfan for cooling.

30- .25 19 20 $630.00 Rack mount, 600 ohm input,overload18k 12.5 protection, telephone paging output.

5.2530- .25 19 34 $714.00 Rack mount, 600 ohm input,overload18k 12.5 protection, telephone paging output.3 5.2530- .25 19 38 $970.00 Rack mount, 600 ohm input,overload18k 12.5 protection, telephone paging output.3 5.2530- 19 23 $620.00 Rack mount, 600 ohm input,overload20k 12.5 protection, telephone paging output.3 6

.01 .03 5- 1.4 7 70 51299.99 Plug-in electronic X -over cape -60k 19 bility, transient -free turn on/

17.75 off, thermal protection..01 .03 5- 1.4 5.25 50 5999 00 Plug-in electronic X -over cepa-

60k 19 bility, transient -free turn on/14.13 off, thermal protection.

.04 .03 5- 1.4 7 54 $799 99 Plug-in electronic X -over cape -40k 19 bility, DDT compression, fan -

13.5 cooled, thermal protection.0.0 0.0 .15 10- 1.0 1.75 12 $749.99 Digital energy comversion amp,

20k 19 DDT compression, fan -cooled,14 MOSFET design.

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DECA 1200 2 325 600 20- 0 0 0.0 .06 10- 1.3 3.88 3720k 20k 19

18DECA 724 2 225 350 20- 0 0 0.0 .1 10- 1.0 3.88 37

20k 20k 19

18M-7000 2 200 350 20- .01 .03 41 10- 1.4 5.25 47

20k 30k 19

16.5OSC AUDIO PRODUCTS, INC.1100 2 50 65 90 20- .01 .01 .01, 20- .83 1.75 12

40k 20kI 19

-1 71200 70 90 20-.01 01 .01 20- .83 1.75 12

40k 20k 19

-1 7UI

1400 200 300 20- 01 01 .01 20- 1 5.25 3440k 20k 19

-1 9.51700 2 325 500 20- .01 .01 20- 1 7 57

40k 20k 19

-1 10.8MX1500 2 330 500 20- .01 .01 .01 20- 1 3.5 47

40k 20k 19

-1 17.9MX2000 2 375 625 20- 01 01 .01 20- 1 5.25 75

40k 20k 19

-1 15.93500 2 300 450 20- 01 01 .01 20- 1 3.5 50

40k 201' 19

-1 1593800 2 375 600 20- .01 0101 20- 1 5.25 75

40k 20k 19

-1 159RAMSA (PANASONIC)WP9440 2 350 10-20- 1.23 525 75

60k 20k 19

-.5 18 BBV/P9220 2 200 300 10-20- 1.23 525 38.6

85k 20k 18.88

-.5 15 06V/P9110 2 100 150 10-20- 1.23 3 5 28.6

85k 20k 18 88

15 06W09055 2 50 10- 05 .05 20- 1.23 175 19

85k 20k 18 88-.5 13 13

RANE CORPORATIONMA6 6 100 150 20-.2 5- .775 5.25 44

20k 80k 19

11

SHURE BROTHERS, INC.-See our ad on Cover IV210 1 6 10 100-3 100- 40mV 2 75 2.13

15k 9.54111111 5.63

SOUNDCRAFTSMEN - See our ad on page 132,3300X4 600 900 450 20- 05 05 008 .05 7 20- 1.0 5.25 60or 4 205 300 20k 20k 19

14PM860 , 2 210 315 450 20- 05 .05 008 .05 20- 1.2 5 20

20k 20k 8.514

450X2 f, 2 210 315 450 20- 05 .05 .008 .05 2C- 1.2 5.25 2820k 20k 19

1011.75

900X2 375 675 900 20-20- 1.22 5.25 5920k 2Ck 19

165RA7501 2 275 420 320 20-20- 1.21 7 47

20k 20k 19

15

SPECTR A SONIC S701 1- 33 58 88 20- .075 0- 2.5 .88

int 20k 20k 10

1.88701BP 1- 122 172 200 20- 05 .075 .025 .025 +5 5

inf 20k 20k dBv 10

1.88712B 2 30 50 80 20- 05 .075 I .025 .025 0 5.5 22

20k dBv 19

14.5712 2 100 100 100 20- 05 .075 .025 .025 0- 0 55 24

20k 20k dBv 19

14.5

$139999

$999 99

$74999

Digital energy con version amp,DDT compression. fan -cooled,MOSFET design.Digital energy con version amp,DDT compression fan -cooled,MOSFET design.Fan -cooled, DDT i.ompression, el-ectronic X -over catransient -free turn on/off.

6568 00 Gain control,head )hone jacks.

$598 00 Rear gain control:, XLR andjacks,octal socket;.

$798 00

$1248 00

$109800

6149800

$1488 00

$195800

As 1200 above.

As 1200 above

Front removeable channel modules,detested gain co itrols,dual monoconstruction.As 3500 above.

62190 00 Intelligent VI limit ng, softoverload charact3ristics.

$1090 00 Has ability to dnie high phase -angle, loads with ease.

$840.00 Detented input a tenuators withremovable knob:.

$590.00 Signal, peak anc protect LEDs,XLR and phone nputs.

$1349.00 Built-in limiters, r.uto bridging,2 -speed fan.

$125.00 Balanced mic input, unbalancedline in -put, ext. 12V power

$1299.00 Multi -channel MOSFET, 2, 3 or 4channel mode Indicators, frontpanel -mounted i.ircuit breakers.

$599.00 Has high curren design to allowstability with 2 cnm loads.

$849.00 High current MC SFET amp with bal-anted or unbalanced inputs.

$1599.00 Same as above.

$949.00 Class H signal t acking designfor maximum eff ciency.

5108.00

2216.00

A modular amp suited for bi, tri,multi -way, usec in noise masking,

!broadcast, recc rding.Is two model 7ii1s bridged togeth-er with the same qualifications.

$595.00 A stereo rack -n ount, self con -tained power amplifier.

$760.00 A stereo rack -mount, self con -tained power amplifier.

I'.1

issee

4110. 0-"e" sc°

.0\ ,,,04ow Isies

-ceso *,ee, secs`; CAlse Sli4Cs

STUDER REVOX AMERICA, INC. -See our ad on page 12Hevox 2 200 230 400 20- .01 .01 20- 1.55 7.7 37.59242 20k 20k 6

-3 14.2SUNNSPL7350 2 225 375 10-.05 .05 .1 10- 1.23 5.25 40

50k 50k 19

-1 15SPL7250 2 160 250 10-.005 .005 .1 .1 20- 1.23 3.5 30

50k 20k 19

-1 14

SYMETRIXA-220 2 20 20 20- .01 20- .5 1.75 9

40k 20k 19

-1 8

TOA ELECTRONI CSP-3000 2 300 480 10- .05 .02 .01 20- 1.23 8.75 77

20k 20k 19

18.75P -150D 2 150 220 10- .05 .02 .001 20- 1.23 5.25 44

20k 20k 19

18.75P -75M 2 75 110 10- .05 02 .001 20- 1.23 3.5 29

20k 20k 19

18.75P -300M 1 300 480 10- .05 02 .001 20- 1.23 8.75 82

20k 20k 19

18.75YORKVILLE SOUND, IN C.AP3000 2 475 750 1200 20- .003 .04 20- 1.4 3.5 45

20k 20k 1915.75

YAMAHA CORPORATION -See our ad on page 10PD2700 2 350 500 10- .03 .os 10- 1.23 5.25

50k 50k 18.891 17.25

P2250C 2 170 250 10- .01 .05 10- 1.23 5.25 41.850k 50k 18.881 16.56

P2350 2 175 250 10- .03 .05 10- 1.23 5.2550k 50k 18.871 11.25

P2150C 2 100 150 10- .01 .007 10- 1.23 5.25 37.450k 50k 18.88

1 16.63P2075C 2 50 75 10- .05 .003 10- 1.23 3.88 19.8

50k 50k 18.88-1 14.38

PC1602 160 240 .01 .015 10- 1.23 5.5 47.850k 18.881 17

PC2602 2 260 400 .007 .015 10- 1.23 7.25 5750k 18.881 17

S3000 00 MOSFET drive and special bipolarpower translstors,two power trans -formers,mono bridgeable.

$899.99 Delayed on/off,protection,soft clipping.

$699.00 As above.

$349.00 Phone and XLR input front panelheadphone jack.

$2218.00 Separate power supplies, stereo,monoswitching, calibrated attenuator.

$1238.00 Magnetic breaker front panel switch,HPF switch,calibrated attenuator.highcurrent headroom.

$938.00 As above.

$1458.00 70/25V transformer,front panel breakerswitch.Also available:P-150M, 150W,S1118.00.

$1599.00 MOSFET drivers,also available AP1200 with625W/Cg2 ohms-$1199.00;AP500 with 250W/C@2 ohms--$799.00.All are bridgeable.

Bridgeable mono, forced air cooling.

$895.00 XLR and 1/4-ininputs,barrier stripoutput, forced air cooling.

XLR and 1/4-ininputs,barrier stripand 1/4 -in. outputs, forced air cooling.

$695.00 XLR and 1/4 -in. inputs,binding post and 1/4\in. out-put jacks, forced air cooling.XLR and 1/4 -In. jacks, bindingpost and V4 -in. output jacks,compact and light -weight

$995.00 Comprehensive protection circuit-ry, XLR in and through connect-ors, 480 watts in mono.

$1295.00 Protection circuitry, XLR in andthrough connectors, model PC2602Mhas 26 -segment backlit LCD meters

$495.00

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A e ° " P

Altec Lansing Corporation10500 West Reno AvenueOklahoma City, OK 73126-0105

ARX SystemsP.O. Box 842Silverado, CA 92676-0842

Ashly Audio, Inc.100 Fernwood AvenueRochester, NY 14621

BGW Systems13130 S. Yukon AvenueHawthorne, CA 90250

Bryston Vermont, Ltd.979 Franklin LaneMaple Glen, PA 19002

Carver Corporation20121 48th Avenue WestLynnwood WA 98046

Carvin Corporation1155 Industrial AvenueEscondido, CA 92025

Crest Audio, Inc.150 Florence AvenueHawthorne, NJ 07506

Crown International1718 Mishawaka Road WestElkhart, IN 46517-1000

Electro-Voice, Inc.600 Cecil StreetBuchanan, MI 49107

ADDRESSES

Hill Audio5002B N. Royal Atlanta Dr.Tucker, GA 30084

Industrial ResearchProducts411 Busse RoadElk Grove Village, IL 60007

Industrial StrengthIndustries15431 Blackburn AvenueNorwalk, CA 90650

Innovative ElectronicDesigns9701 Taylorsville RoadLouisville, KY 40224

JBL Professional8500 Balboa Blvd.Northridge, CA 91329

Paso Sound Products, Inc.14 First StreetPelham, NY 10803-1401

Peavey Electronics711 A StreetMeridian, MS 39301

QSC Audio Products1926 Placentia AvenueCosta Mesa, CA 92627

Ramsa (Panasonic)6550 Katella AvenueCypress, CA 90630

Rane Corporation10802 47th Avenue WEverett, WA 98204-3400

Soundcraftsm en2200 South RitcheySanta Ana, CA 92705

Spectra Sonics3750 Airport RoadOgden, UT 84405

Studer Revox America, Inc.1425 Elm Hill FikeNashville, TN 37210

Sunn1130 Columbia StreetBrea, CA 92621

Symetrix, Inc.4211 24th Avenue WSeattle, WA 98199

TOA Electronics, Inc.601 Gateway Blvd.S. San Francisco, CA 94080

Yamaha Corp. of AmericaP.O. Box 6600Buena Park, CA 90622-6022

Yorkville Sound, Inc.4600 Witmer Industrial Estate,Unit #1Niagara Falls, NY 14305

DAN BUXBAUM

1990 Winter NAMM Round -Up

This year's winter NAMM show has certainly been an impressive one. A wide variety ofproducts were displayed and introduced, and even the odd fire -breathing monster made anappearance (the giant, green plastic type, courtesy of Ibanez). The following is a compendium ofvarious manufacturers with products designed for the professional audio environment. This is anon -comprehensive summary, and my sincerest apologies to anyone left out due to space, andmy own, limitations. Also, manufacturers who did not display new products have been omitted.Now, with all the technicalities out of the way, let's begin our alphabetical listing:

APHEX SYSTEMSAphex introduced their new processor the EXPRES-

SOR compressor/limiter. This single channel unit em-ploys standard features such as: adjustable input, thre-shold, attack, release, output, and ratio, as well as hard orsoft knee compression, link, and slave. The EXPRES-SOR's special features include adjustable HighFrequency Expansion to counteract the dulling effect ofhigh compression ratios, and the Spectral Phase Refrac-tor (SPR) which was first introduced on the Aural Ex-citer Type III. SPR corrects the bass delay anomaly as-sociated with the recording and reproduction processes,to restore clarity and openness, and significantly in-creases the apparent bass energy level without addingany amplitude equalization or "bass boost."

APPLIED RESEARCH & TECHNOLOGYART unveiled a whole new family of impressive signal

processors and delay systems. Leading the way is theSGE MACH II processor which offers twelve simul-taneous effects and 20 kHz bandwidth. The MACH IIhas over seventy different effects including: exciter EQ,compressor limiter, noise gate, expander, sampler; en-velope filter; pitch transposer line EQ, stereo panner,stereo chorus and flange, twelve distortions, twenty-onedelay types (two full seconds), and twenty-four differentreverb algorithms. It also features real-time MIDI andtwo -hundred memories.

The DR -X is a studio digital reverberator/dynamicsprocessor/pitch transposer/sampler which offers 160Kbytes of audio ram, bandwidth to 20 kHz, sampling, tensimultaneous audio functions, an exciter EQ, compres-sor, etc. It also features twenty-one different delays (twofull seconds), twenty-four reverb algorithms, two-

hundred memories, and comprehensive real-time MIDIcontrol.

The MultiVerb III signal processor is four -hundred-

percent more powerful than its predecessors, and fea-tures a new series of algorithms with four -times the pre-vious resolution. The MultiVerb III has over fifty-threeeffects (up to four simultaneously) including: sampling,twenty-one delay types, stereo panning, pitch transpos-

ing, twenty-four reverbs, two -hundred memory loca-tions, and full programmability and performance MIDIcompatibility. The MultiVerb LT offers the sounds andperformance of the MultiVerb III, but at a very competi-tive price ($299.00). The LT has the simplicity of one -touch control commanding the one -hundred -and -

ninety -two studio multi -effect combinations. This unitis also MIDI addressable.

ART's new delay systems, Delay System V and DelaySystem VII, feature new circuit designs with full 16 bitADA converters and offer 20 kHz bandwidth. Both unitsfeature rotary type pots or encoders allowing the user tomanually "tweak" delay, width, chorus, and flange set-tings. Because of the extreme range of control, chorussettings deeper and richer than most digital units allow,can be achieved. The Delay System V is a non -pro-grammable delay/super choruser that features controlsfor: range, bypass, feedback invert, and infinite repeatalong with rotary pots for delay, speed, depth, and width.The Delay System VII uses the same audio current, but isfully programmable. The mix is also programmable andall parameters are visible on L.E.D. readout. The DelaySystem VII is also a sampler allowing the user to capturesamples, truncate them and vary their pitch, and may betriggered manually or automatically.

AUDIO-TECHNICA U.S., INC.

Audio-Technica has also added to their popular line ofmics. Added to the versatile AT871 UniPlate micro-phone is a new, smaller version (AT851A Micro Uni-Plate), a phantom -powered design (AT871R), and a newomnidirectional model (AT841A OmniPlate). The sizeand versatility of these mica enable them to be used effec-tively in a wide range of applications, especially in situa-tions that demand surface mounting and minimum visi-bility. Audio-Technica also introduced their PRO22microphone which has been designed for close-up appli-cations, and their new 600 Series line of performanceheadphones.

COMMUNITY LIGHT AND SOUND INC.Community Professional Sound Systems previewed

two exciting new sound reproduction systems designedexclusively for the demands of the cinema environment.The TheatreStar III is the first three-way loudspeakerdesign of its type built exclusively for behind -the -screencinema applications. The TheatreStar has severalunique features including the use of a Community M200loudspeaker for midrange frequencies between 400 Hzand 3500 Hz for extremely clear dialog intelligibility. Anexclusive trapezoidal -pattern high frequency horn pro-vides uniform sound distribution throughout the view-ing audience. The TheatreStar III utilizes its very preciseWavefront Coherent design which allows the fullfrequency spectrum to arrive at the listener's ears at ex-actly the same moment in time, providing remarkabledefinition and clarity in its sound reproduction.

The SurroundStar II is a compact, unobtrusive two-way loudspeaker system designed to provide uniform,realistic sound quality from the surround channels of acinema sound system. The SurroundStar II features apowerful eight -inch low frequency/midrange speakercrossed over at 2000 Hz into a unique trapezoidal -pat-tern high frequency horn. The SurroundStar II is only 6 -and -1/4 -inches deep, and is wrapped in black acousti-cally -transparent cloth, blending easily and almostinvisibly into most theater designs.

The RS880, VBS415, and 880EQ are the latestdevelopments in Community's RS Series of WavefrontCoherent loudspeaker systems, and are designed tooperate as a complete system. The 880EQ is the control-ler: it provides a crossover between the RS880 full -rangesystem and the VBS415 subwoofer. The RS880 is athree-way trapezoidal, arrayable loudspeaker systemdesigned for professional applications. The RS880 andthe VBS415 enclosures are fitted with handles, and op-tionally, with three or six "D" -ring flying points.

The new M4 CoAx bracket system enables any of Com-munity's PC400 Series high -frequency horns to be coax-ially mounted directly in the center of a matchingM4/PC/500 Series horn, thereby improving polar re-sponse and adjacent horn performance. The M4 CoAxbracket system is available bolted into a PC1500 horn fornew installations, or as a bracket and hardware packagefor retrofitting existing installations of current modalPC1500 horns.

DOD ELECTRONICSDOD introduced their new series of mixers, the 820

and 1220 stereo mixers. These mixers are compact, yetmaintain studio -quality sound reproduction. Features ofthese mixers include: high and low impedance inputs, 15dB cut/boost EQ'ing, table or rackmount configurations,phantom powei RCA -type stereo tape outputs, auxiliaryinputs, individual monitor sends, effects send andmono/stereo returns, 60 mm dust -shielded faders, andrubberized knobs. The 820 series features eight stereochannels, while the 1220 series has twelve stereo chan-nels. There are six different models of these mixers, andthe various configurations include the 820 and 1220with line -only applications, and the 820 XL and 1220 XLwith high/low impedance in table -top formats, to the 820RM and 1220 RM with full -balanced and un-balanced

input capability in rackmount configurations. The pricesof these mixers are quite affordable, and range from$399.95 to $699.95.

ELECTRO-VOICEElectro-Voice introduced their new N/DYM Series II

line of dynamic mics. EV is employing a new vibration -isolation system, DynaDamp, on these mics to reducehandling noise, cable -transmission noise, and clicks andthumps. The soft but firm feel, and black matte finish oftheir Warm -Grip sleeves make these new mks distinc-tive. The trademarked DynaDamp and Warm -Grip (bet-ter absorption and increased protection) contribute to animproved N/DYM series of dynamic mica.

We also got a chance to hear EV's new MT -4 ManifoldTechnology concert system firsthand, at a concert fea-turing Giant and Extreme, two rock bands. The MT -4system was used for the mains, and the sound at theshow was both clear and "punchy." The new MTS -1stage speaker system, derived from the MT -4 ManifoldTechnology concert system was also introduced. Thisunit is a compact, manifolded, two-way, biampedspeaker system and is recommended for use in situationswhere space is limited and efficiency is a major factor.

FOSTEX CORPORATION OF AMERICAFostex introduced their new Model 280 Multitracker, a

four -track recorder with impressive programmablememory functions. The three programmable memorycue points are the zero reference,2; and each one can be set, confirmed, and changedeasily. This unit can automatically locate the "zero"mark and the memory 1 and 2 cue points-a real time-saver and headache-preventer. The Model 280 can alsoautomatically return to the memory 1 cue point uponreaching the memory 2 cue point. These automaticoperations really allow the user to concentrate on beingcreative-the main objective, anyway.

The Models 454 and 812 (four -bus and eight -bus, re-spectively) are Fostex's new recording mixers. TheModel 454 is affordable (under $1,000.00), and some ofits many features include in -line monitoring, dual para-metric equalizers for low end and midrange, and outputsolo. The two effects sends are: mono, post EQ and fader,and stereo, with a three -position selector-pre EQ andfaded post EQ and fader, or tape (playback). The Model812 features dual parametric equalizers for the low end(60 Hz to 1 kHz) and midrange (400 Hz to 6 kHz). Thehigh end has a shelving -type equalizer fixed at 10 k/Hz.This unit also has two mono effects sends and a stereoaux send. The stereo aux send bus has both pan and gaincontrols and is switchable from the post -fader signal tothe tape playback signal. An import2 nt function of thisbus is its ability to monitor a "wet" input signal while re-cording "dry" This is an outstanding multi -track mixerthat is also fully MIDI -compatible.

SENNHEISER ELECTRONIC CORPORA-TION

Sennheiser introduced a variety of new microphones,new stereo headphones, and even a new mic stand. The Cr'

MKH 50-P48 is a new member of the symmetrical trans-ducer, tranformerless MKH Series, designed to meet thedemands of digital recording. This condenser mic exhib-its a highly frequency -independent supercardiod polarpattern for attenuating sound pick-up from the sides andrear of the mic. The MKH 50-P48's low noise floor; lowdistortion and high sensitivity combines for a dull dy-namic range.

The MKH 70-P48 RF condenser super-cardiod/lobe isa new, long shotgun mic. The mic is designed for long dis-tance sound pick-up, and is lightweight, yet very reliableas the RF condenser principle is virtually immune tohumidity and moisture. A new symmetrical pull -pulltransducer design significantly reduces both intermodu-lation and harmonic distortion products. The newMD518 dynamic mic is designed for sound reinforce-ment of high sound pressure signals including vocal, gui-tar, and percussion mic'ing. A smooth cardioid pickuppattern insures maximum rejection of unwanted soundsfrom the rear of the MD518 and allows for use in closeproximity to stage monitors and sidefill cabinets. TheMD518 is highly insensitive to the strong magnetic ef-fects of loudspeakers; therefore, it can be utilized withconfidence near large stage speakers.

Two new headphones introduced by Sennheiser arethe HD 450 Studio Stereo Headphone and the HI) 25Studio Monitoring Headphone. The HD 450 is a supra -

aural Open -Aire model that is a durable, acoustically ac-curate, high impedance headphone. The HD 450 Studiois designed to hold up to the rigors of studio or field use,and comes with a canvas carrying case. The HI) 25 util-izes dynamic drivers in a closed supraural design to offera lightweight and comfortable professional headphone.Also, if you wish to cue with single muff monitoring, theHD 25 allows one driver to rotate off the ear and onto theuser's temple.

Additionally, Sennheiser's new mic stand (the SEMSseries) has some new features that gear it towards thestudio or for the touring life. The boom joint does not con-tain any support hardware that might break in shipping.Reinforced knobs are used that can withstand the rigorsof touring. Also, plastic friction washers are used to in-sure that the boom will always hold its position.

SHURE BROTHERS INC.

Shure Brothers introduced a new addition to their il-lustrious L Series line of wireless microphone products-the L2 Handheld Transmitter. The L2 comes in threedifferent versions that are all compatible: the ModelL2/58 features the famous SM58 dynamic microphoneelement, the Model L2/96 incorporates the condenserelement used in the high-performance SM96 vocal con-denser mic, and the L2/Beta 58 featuring the acclaimedBeta 58 element. The mic transmitter heads are inter-changeable, so any of these three elements can be usedwith the same L2 transmitter. These various heads canbe changed in seconds-making the L2 Handheld Trans-mitter extremely practicable and useful in many differ-ent situations.

SONY CORPORATION OF AMERICASony Professional Audio introduced new additions to

their already prestigious wireless microphone lines, bothin UHF and VHF versions. The WRT-67 Dynamic UHFwireless mic, using a uni-directional dynamic capsule,offers warm response on the low end and the "punch" re-quired for vocals. This wireless mic operates on batteries(a single "AA" battery provides for over three hours ofcontinuous operation) or optional A.C. power supply.

The newest development in Sony's UHF wireless mi-crophone technology is the WFtR/WRT-28 System. TheWRT-28 (the transmitter) operates on a carrierfrequency from 947 to 952 MHz, with RF output powerof 30 mW, and frequency stability of ±0.005 -percent.The WRR-28 (wireless mic) features a balanced micro-phone level output and a water-resistant ease. This unitis a marvel in that Sony has incorporated such a high -qu-ality transmitter into such a compact and lightweightsystem. The performance is high -end quality, and thesmallness of the unit allows for easy concealment-idealfor live performances.

The VHF 400 Series wireless mic system incorporatesminiaturized frequency synthesis components whicheliminate the need for a larger equipment inventory toobtain reliable wireless operation. An amazing feature ofthis system is that it is capable of operating on any of 48separate frequencies-the system's receivers areequipped to handle all 168 channels in the assignedband. The major components of the VHF 400 Systemare: the WRT-410, a one-piece unit combining the trans-mitter and a hand-held dynamic mic, and the WRT-420,a bodypack transmitter supplied with an ECM -77Blavalier-type mic.

Additional products shown were the MU -R201 stereodigital reverb (shown for the first time), and the TCD-D10 PRO portable DAT recorder coupled with the ECM-MS5 M -S stereo mic. The MU -R201 employs 16 -bitlinear quantization and a 26 kHz sampling frequency.This stereo digital reverb has ten basic algorithms in-cluding. reverb, gated reverb, delay, reversed reverb,auto pan, and various combinations of functions whichhelp the user to save time and control costs. An ex-tremely useful feature is that this unit's algorithms aredefined by 26 parameters which can edit a preset soundoutput-this enables you to tailor the preset sound toyour own specific tastes and needs. This makes the MU -R201 ideal for recording studios, post -production suites,live performers, broadcasters, and sound reinforcementagencies. The MU -R201 also includes a MIDI interfacefor effective control of any parameter; memory numberor effect level in a MIDI -based system.

The TCD -D10 PRO portable DAT recorder is designedfor both studio and field use. Among its many featuresare: S/P DIF and AES/EBU-type digital input/outputports, 2x oversampled digital A/D and D/A converters,and a rechargeable battery-providing up to 1.5 hours ofcontinuous operation on a single charge. The ECM-MS5stereo mic is also well -suited for indoor and outdoor ap-plications. Weighing in at less than eight ounces, andmeasuring just 8.75 inches in length, the ECM-MS5 isextremely comfortable to use, yet its matched uni-directional electret condenser capsules assure a phase -coherent image, while a low-cut switch enables users toroll -off low frequencies to achieve optimum recording byreducing unwanted wind noise or vibrations. This mic

also comes supplied with cable and urethane wind-screen.

SOUNDCRAFTSMENSoundcraftsmen introduced two new professional

power amplifiers, the Model DJ600 and the ModelDJ900. Both units were designed specifically for the DiscJockey and Club and Commercial Installation Market,where high power as well as superb sound reproductionis required. The DJ600 Power Amplifier combines all ofthe best features of Mosfet amplification and multi -im-pedance, high current design to provide great sound. Thenew DJ600 multi -impedance amplifier is designedspecifically to provide not only the high current neces-sary to drive low impedances, but also to provide un-matched musicality in driving loudspeakers of any im-pedance, from as low as 2 ohms to as high as 32 ohms.

The DJ900 Power Mosfet Amplifier combines the bestfeatures of Class A, Class B, and Soundcraftsmen's pro-prietary and unique Phase Control Regulation circuitryto also provide great sound. The new ultra -high -currentdesign of the DJ900 allows this amplifier to perform ef-fortlessly under the most demanding conditions-theDJ900 can handle impedance as low as 2 ohms! TheDJ900 Power Amplifier's Mosfet output stages offersthe utmost audio clarity and distortion -free sound repro-duction.

TASCAMTascam, the professional division of TEAC, unveiled

an impressive array of new items ranging from DAT Re-corders and mixdown decks, to high-speed, four -trackrecorders and thirty -two -channel consoles. The PortaTwo HS is a high-speed version of Tascam's popularPorta Two four -track machine. This new recorder util-izes 3 W4 in./sec. tape speed which provides users with agreater sonic quality to their cassettes.

Especially impressive are the two new MIDI -compat-ible mixer/recorders: the 644 MidiStudio (four -track ver-sion) and the 688 MidiStudio (eight -track version). Boththese units provide excellent versatility and sound in allsmall studio recording and mixing applications, whilealso incorporating built-in MIDI -to -tape synchronizers

which allow MIDI tracks to chase -lock to each unit's in-ternal multi -track recorder. The flexibility and useful-ness of these products, all in a self-contained, lightweightunit, is quite impressive. Tascam also introduced abalanced version of their quality unbalanced 112 modelmixdown deck, the four -track, two -channel 112B.

The new DA -30 DAT recorder is an affordable($1,899.00), stereo deck which features 64 -times over -sampling and Delta -Sigma modulation in the analog -to -digital converters, while the digital -to -analog convertersfeature 18 -bit technology with eiglr-times oversam-pling. Combined, this results in the achievement of a S/Nratio in excess of 94 dB. Finally, the M-3500/24 and M-3500/32 (twenty-four and thirty-two tracks, respec-tively) are new mixing consoles. Both units are perform-ance -oriented consoles, with a wide range of features,and affordable prices. The M-3500/24 is priced at$7,499.00, while the M-3500/32 is priced at $8,499.00.

YAMAHA CORPORATION OF AMERICAAlthough Yamaha specializes in its wide, quality as-

sortment of musical instrument lines at the NAMMshow (including guitars, basses, drums, guitar and bassamps, etc.), various pro audio, non -instrument productsare also displayed. One such unit generating a lot ofpress, and certainly deservedly so, is the DMR8X-a self-contained mini studio. This amazing unit has built-infeatures including: an eight -track DAT recorder, atwenty-four track mixer, a SMPTE synchronizer, andvarious signal processors including EQ, compression, re -verb, limiting, delay, etc. The DMR8X additionally hasits own automated mixing system, also built-in.

The Yamaha DMR8X has the ability to take youranalog recording signals, convert them to digital, and doeverything other eight -tracks can do, only in a digital for-mat. The DMR8X processes, mixes, and records, all digi-tally, in one package! This product accepts all the majordigital and audio formats and also generates MIDI TimeCode. Be prepared, howeve4 that this amazing productdoes have a list price of $35,000. I wanted to end this1990 Winter NAMM round -up with a grand finale, andthe DMR8X certainly provides the fireworks in that de-partment.

Life in the fast food lane.It can be a slow death if

you're loading up on high -cholesterol, high -fat foodsthat may eventually chokeyour arteries and damageyour heart. If you're a teen-ager, slow down on fast foodthat's high in fat. Chancesare it'll catch up with yousomeday if you don't.

American HeartAssociationWE'RE FIGHTING FORYOUR LIFE

CON-

Alcui Neh4(44

DYNAMIC VOCAL MIC The new N/DYM N/D857 micro-

phone is designed specifically forconcert vocal applications, wherehigh gain -before -feedback and ex-tended response are critical. The ad-dition of a unique acoustical pathcorrector provides increased sensi-tivity and an extremely uniformpolar pattern throughout the vocalfrequency range. This gives theN/D857 a tight, supercardiod polarpattern with superb off -axis rejec-tion and increased gain -before -feed-back, allowing high monitor levels.The N/D857's switchable bass roll -off employs a second -order high-passfilter with an 80 -Hz cornerfrequency, for a 12 -dB -per -octaveroll -off that further eliminates hand-ling noise without compromisingvocal sonic quality. The roll -off alsoprovides increased flexibility withvarious stage situations, includingthe high bass output of large sub-

woofer arrays, low -frequency stand-ing waves and vocal styles. Because itis designed to handle high SPL andhas a tight polar pattern, the N/D857is also suited for mic'ing amplified in-struments.Mfr.-Electro-Voice, Inc.Price: $450.00Circle 60 on Reader Service Card

AUDIO OP AMP The LT1115 is a new audio oper-

ational amplifier with 0.9 nanovoltsper root Hertz noise at 1 kHz and lessthan 120 nanovolts (rms) noise overthe DC to 20 kHz audio spectrum.The minimum slew rate of theLT1115 is 10 volts per microsecondand its minimum gain -bandwidthproduct is 40 MHz. Minimum volt-age gain is 2 million. Applications forthe LT1115 include high -end pream-plifiers, CD audio players, digitalaudio tape recorders and players, hy-

drophones, infrared detectors, andlow noise frequency synthesizers,where extremely low noise and dis-tortion are also necessary. TheLT1115 is available in 8 -pin plasticdual -in -line packages and 16 -pinsmall outline packages, and is availa-ble from stock.Mfr.-Linear TechnologyCorporationPrice: $2.95 (100 -up pricing in the8 -pin package)

CATALOG This is a totally new 138 -page cat-

alog of Electronic Test Accessories.Ten major product categories arepresented via an easy -to -use index,also including the company's mostpopular selection of jumpers and ca-bles, boxes, plugs and jacks, connec-tors, adapters, single -point test clips,and static control devices. Designedto provide a complete guide and ref-erence to Pomona's growing familyof IC Test Clips and Adapters, andCable Assemblies and Adapters,helpful selection guides are providedfor the user.Mfr.-ITT Pomona ElectronicsPrice: FreeCircle 61 on Reader Service Card

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VOLTAGE COMPUTERAND MIC SLIDE RULE Crown's new Constant Voltage

Computer can be used to calculatethe correct transformer taps to usewhen constant voltage lines otherthan 70V are desired. In addition, italso quickly calculates line loss, theeffects of inverse square law, and therelationship between power inputand SPL. This device is valuable be-cause it not only tells you whichtransformer taps to use to achieve adesired voltage, but reveals the loadimpedance to the amplifier as well. Itdoes all this merely by aligning thenumber of watts desired on its"Rated Power" scale with the num-ber of volts needed on its "Rated Volt-age" scale. Most importantly, thevoltage computer takes the guess-work out of system engineering.With its use, the exact number of am-plifiers can be determined for anyjob, and line loss can be figured pre-cisely. Complete with its own easy -to-

follow instructions, the ConstantVoltage Computer is the perfect com-panion for all Com-Tech amplifiers,which have the flexibility to drive

voltage lines at 25, 35, 50,100, or 140VCrown's Microphone Sensitivity

STUDIO MONITORS Model LS161 studio monitors are

mirror -imaged, two-way, acoustic -suspension driver systems, en-gineered to be compatible withtoday's recording technology. Bymirror -imaging, these monitorseliminate the response dips whichcan occur in the upper harmonicstructure of the human voice range.Other design features include: pointsource vocalization, minimum phaseshift, fast transients due to lowmoving mass, time corrected driverplacement, a self -resetting, thermo-controlled fuse on the tweeter, con-nections are gold-plated, solid steel,5 -way binding posts, and the cabi-nets are available in natural oak orblack oak lacquer.Mfr.-Digital DesignsPrice: $349.00/pairCircle 64 on Reader Service Card

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Slide Rule helps you to convert easilyfrom one microphone -sensitivityspecification to another. These in-clude open -circuit sensitivity, powersensitivity, and EIA sensitivity. Italso lets you calculate the mic outputvoltage for a given input sound pres-sure level. In addition, the slide rulehelps you determine a microphone's

impedance ifyou know its power sen-sitivity. The jacket provides usefulapplication examples and info:Illa-tion on microphon directional char-acteristics.Mfr.-Crown International, Inc.Price: $5.00 (for each item)(covers postage and handling)Circle 63 on Reader Service Card

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How To Produce Great Radio Com-mercials, by Brian Battles. Thisunique four -cassette package con-tains essential tips and advice thatteach you how to set up your ownlucrative advertising productionbusiness, and the presentationshowcases sample spots usingmany of the techniques describedin this column, and much more.To order your copy, please send acheck or money order for S99.95(includes domestic shipping) to:Porkpie Productions, P.O. Box176, Colchester, CT 06415-0176.

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As a non-profit organizationwhich has traditionally attractedwide volunteer support from the pro-fessional audio community, an or-ganizing committee of the SpecialOlympics is once again seeking helpin providing sound reinforcement forthe many sporting and entertain-ment events held during the upcom-ing International SummerSpecial Olympics slated for July19-27, 1991 in Minneapolis, Minne-sota.Promising to be the largest Special

Olympics showing to date, the sum-mer 1991 games will attract over6,000 special athletes and 2,500coaches from 90 countries world-wide. Preparations are also beingmade for the arrival each day of over50,000 spectators, who will witnessathletic endeavors including swim-ming, diving, field and track,basketball, bowling, canoeing, cy-cling, tennis, softball, power lifting,and team handball.Those interested in donating time,

equipment, or cash contributions tothis event should contact audio or-ganizers Beryl Moore, Joe Wisler,or Gil Nichols at Crown Inter-national. Please call Mondaythrough Friday during regular officehours at (219) 294-8000, or write tothem in care of Crown at P.O. Box1000, Elkhart, IN 46515. Underwriters Laboratories

Inc. (UL) and JMI Institute havesigned a joint Memorandum of Un-derstanding that will provide qualityassurance assistance to Far East andU.S. corporations interested in gain-ing access to the European Commu-nity (EC).Under the new agreement, UL and

JMI may accept each other's evalua-tion of manufacturers' quality sys-tems for registration to the Inter-national Organization for

Standardization's (ISO's) 9000 Ser-ies Standards. The EC has adoptedthe ISO 9000 Standards and iden-tified them as European Norm (EN)29000 Series Standards. Thesestandards are expected to becomethe governing documentsthroughout Europe for evaluatingmanufacturers' quality systems.The ISO 9000 Standards provide

models for various quality assurancesystem levels, as well as generalguidelines for establishing and main-taining a quality management sys-tem. The UL/JMI joint memoran-dum is intended to provide amechanism for either organization(UL or JMI) to evaluate a manufac-turer's quality assurance system andto register the system with UL, JMIor both UL and JMI to ISO 9000 andEN 29000 Standards.UL is known nationally and inter-

nationally for its work in producttesting, safety certification, qualityassurance and standardization. JMIis known for its work in evaluatingelectronic products and buildingmaterials for the Japanese govern-ment.

Telarc International an-nounced the opening of a Europeanoffice in Paris, France. Heading theoperations there will be GerardSchoumann, as Director of Salesand Marketing in Europe. Mr.Schoumann, who graduated fromthe Sorbonne in Paris with a degreein Law, has an extensive backgroundin the recording industry, beginningwith Polygram, where he was theLabel Manager for DeutscheGramophone in France. In 1986,he became the Marketing Managerof Classical Repertoire for CBSMasterworks in Europe, and in1988, he was named Director of theClassical Department for that labelin France.

Altec Lansing Corporation re-cently hosted two sound clinics heldin Europe. These clinics drew recordattendance in Frankfurt, West Ger-many, and Zagreb, Yugoslavia. Morethan 200 Altec distributors and theircustomers, as well as consultants,electrical engineers and contractors,attended each of the two-day clinicshosted by Altec Lansing -Europe,a division of Mark W Vertriebs,GmbH.The international forum-a United

Nations of Sound-saw delegatesrepresenting companies fromAustria, Bulgaria, Denmark, Eng-land, Finland, Germany, Greece,Holland, Italy, Norway, Rumania,the Soviet Union, Switzerland,Turkey, the United States, andYugoslavia. The program at the clin-ics was translated from English intoGerman, Russian, and Serbo-Croatian.Programs, seminars, demonstra-

tions and presentations ranged fromarchitectural acoustics to sound sys-tem design, and from understandingsound products to computers inacoustical engineering and elec-tronic design. Altec Lansing Presi-dent Dave Merrey was quoted assaying, "to my knowledge, the clinicin Frankfurt was the first full-scaleclinic Altec ever conducted in West-ern Europe, and the one in Zagrebwas the first sound clinic any majorpro sound company has ever held inthe eastern part of Europe. We areexcited over the enthusiastic re-sponse and proud that we can add yetanother chapter to our history ofpioneering the acaievement of bettersound throughout the world."

Neve Electronics Inter-national announces the appoint-ment of Hazel Simpson as Directorof Sales. Ms. Simpson will be re-sponsible for sales both in the UK and co

via Neve's world-wide network ofdistributors. In related news, Neveannounces the appointment of JoeNaccarato to the position ofGeneral Manager Rupert NeveCanada, Inc. Prior to joining Neve,Mr. Naccarato was Sales Managerfor Studer Canada. As part of thisnew appointment, Mr. Naccaratowill be responsible for all Neve andMitsubishi Digital Pro Audiosales in Canada.Also, Neve North America has

named Charles Conte to the posi-tion of Public Relations Administra-tor for the North American market.Mr. Conte comes to Neve fromStuder Revox America in Nash-ville, where he has been Public Rela-tions Manager since October 1987.As PR Administrator, a newlycreated position within Neve, Mr.Conte will be responsible for writingall Neve and Mitsubishi DigitalPro Audio press releases, and willwork directly with the trade press topromote both product lines.

DOD Electronics announcesthe hiring of Richard Bos asMarketing Manager. In his new posi-tion, Mr. Bos will assume responsi-bility for corporate and productmarketing strategies, including newand existing product development,market research and analysis,advertising, promotions, P/R, andtrade shows. Mr. Bos comes to DODwith an extensive and successfulbackground in marketing and adver-tising both at the corporate level andin ad agencies. He has 25 years ex-perience as a lead guitarist forvarious local scene rock and rollbands and has played warm up for anumber of top bill rock groups. Hisbusiness and gig experience includesthe U.S., Europe, East Germany,Asia, and South America. He has res-ided and worked in a number of for-eign countries.

The Hollywood Association ofRecording Professionals(H.A.R.P.), the professional trade as-sociation for commercial recordingstudios, has elected Terry Williams,co-owner of Lion Share Studios,as the organization's 1990 Presi-dent. Since its formation early lastyear H.A.R.P has brought togethersome of L.A.'s most respected studioowners to address traditional busi-ness issues such as group health in-

surance, employee benefits, andequipment purchasing, as well astrends and concerns exclusive to therecording industry. H.A.R.P. is cur-rently engaged in an aggressivemembership drive, which will belaunched by direct mail to localstudio owners in the coming weeks. The National Association of

Broadcasters' EngineeringConference Committee hasselected Hilmer I. Swanson, asenior staff scientist at Harris Cor-poration's Broadcast Division,Quincy, IL, to receive NAB's En-gineering Achievement Award.Swanson is responsible for much ofthe technology used in AM transmit-ters today. Work by Swanson hasdramatically lowered the power re-quirements for transmitters, savingAM radio stations an estimated $50million in extra power costs over theyears. At Harris, Swanson made sig-nificant contributions in thedevelopment of pulse modulationtechniques and more recently, digitalmodulation for AM radio. Many ofSwanson's patents represent thesame standards and benchmarksused by transmitter designers world-wide.

AMS Industries plc (UK) an-nounced plans to relocate theirwholly owned subsidiary AMS In-dustries Inc., to Northern Cal-ifornia under the control of JimStern, President and CEO, in amove to further expand their U.S.operations. Nigel Branwell, whohas run the operation from Seattlefor the past two years, remains inSeattle and will become the repre-sentative for AMS products in theNorthwest area. Also, AMS productswill be represented in the states ofTennessee, North and SouthCarolina, Georgia, Florida, Missis-sippi, Alabama, Louisiana, andTexas by Interface Audio underthe direction of Ridge Nye, Presi-dent. FSR, Inc. has just purchased a

30,000 square -foot manufacturingfacility in West Paterson, New Jer-sey. The company, which manufac-tures audio and video control equip-ment as well as custom metalfabrication, will move into their newhome in March. Their new address is244 Bergen Boulevard, West Pater-son, NJ, 07424.

Applied Research & Tech-nology, Inc. (A.R.T.) has moved tonew facilities. The new factory is ap-proximately double the size of theirprevious factory. The new buildingwas designed to utilize the latest inproduction and assembly automat-ion, yet integrate all other businessfunctions. In addition, A.R.T. con-tinues to add to its manufacturingtechnology base with four new piecesof equipment designed to facilitatethe entire printed circuit board as-sembly process, from component in-sertion to final test. International Music Com-

pany announced the appointment ofWoody Moran as the new Directorfor all AKAI Professional andDigital products in the UnitedStates. Mr. Moran will be responsiblefor coordination and direction of allAKAI activities in the U.S. Studer Revox America, Inc.

(SRA) has relocated its Western Re-gional Sales office to larger premisesin the San Fernando Valley. The3,200 square feet of available spaceat the new office complex has beendivided into a new showroom anddemo area, enlarged office space,plus a fully equipped service center.The new West Coast address for SRAis 16102 Hart Street, Van Nuys, CA,91406, the phone and fax numbersremain unchanged. WaveFrame Corporation an-

nounces its planned merger with Cy-bermation, Inc. of Long Beach, CA,maker of the CyberSound editorialsystem. Concurrent with the merger,WaveFrame announces the raisingof $3.5 million in capital to fundgrowth. WaveFrame will be headedby Charles Grindstaff as Presi-dent and Chief Executive Officer,John Melanson as Chief TechnicalOfficer, and Steve Krampf asSenior 'Vice President of Sales andMarketing.In related news, Martin Audio

Video Corporation has beenselected by WaveFrame Corpora-tion to represent its product line inthe New York, tri-state andmetropolitan area, including Wave -Frame's AudioFrame Digital SoundProduction System, which is used bymusicians, the recording industryand jingle companies, as well as inthe production and audio enhance-ment of film and video.

M FA

THI TR.'ERB 11A R T proudly introduces a stunning new vers onof one of the finest sounding effects processorsever made. The Multiverb II offers four studioquality effects at once. pitch transposing. Per-formance Midi. and new reverb algorithms thatborder perfection-with ncise and distortionfigures dramat cally lower -han comparable unrs1The Multiverb I offers more power and perfor-mance than anything in its class.

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THE MULTIVERB EXTSampled Perfection' Th1s new super-effXtordoes everything that the Multiverb II does withdelay :ime of two full seconds and studio qualitysampl ngi You can crea e shimmering layeredsounds and sample on he fly using manual orautomatic triggering. B sides using fcur effectsat once, you can contr I everything in real timewith Ferformarce Midi*. The EXT provides theamazing reverbs and musical accuracy thatA.R T isfamous fcr,with the powerto create allyou can'magi le AL

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Shure L Seriesbrings reliability to affordable wireless.

Why take chances with anything else?If you're providing wireless micro-

phone systems to churches, schools, orother value -conscious users, you need reliable

equipment you can sell at an affordable price-andmake a profit doing it.

That's what the new L Series from Shure is all about.The L Series sets a new standard of value in its pricerange, offering features, performance and reliabilityother "economY" systems can't match.

We didn't forget the details.Designed and built by Shure in the U.S.A., L Series

systems include many of the features that set profes-sional -quality wireless systems apart from the "toys."L Series receivers are sturdy, metal -cased, and rack-

mountable. Antennas are detachable and may beplaced in remote locations, providing excellent per-formance in situations where many other wirelesssystems have trouble.

Our Ll Body -Pack Transmitter has features like asarate audio mute switch and a universal 4 -pin"Tiny QG" connector that accepts a variety of micro-phone and musical instrument sources. And L Series

lavalier systems come with the 839W, a reliable Shurecondenser microphone designed for clear, naturalvocal pickup.

Performance meets economy.Even though L Series components are economically

priced, they incorporate sophisticated RF technology.The L4 Diversity Receiver utilizes "intelligent"MARCADTM circuitry to monitor signals from its twoindependent RF sections, blending them in the opti-mum proportion-not merely switching them. Theresult is reliable, uninterrupted audio with no clicks,no pops. And all L Series systems feature Shure"Mirror Image" companding, plus high -gain, low-noise MOSFETs, a high-fidelity quadrature detector,and a 3 -pole Chebyshev audio low-pass filter. It alladds up to outstanding audio quality with exceptionalfreedom from noise and distortion.

Why risk callbacks with anything else?Other systems may not meet expectations. But you

can recommend a Shure L Series system with confi-dence. So why risk callbacks-and your reputation-with anything else?

THE SHURE° WIRELESS

THE SOUND OF THE PROFESSIONALS®...WORLDWIDE222 Hartrey Avenue, Evanston, IL 60202-3696

See us at NSCA, booth number 705/804 Circle 12 on Reader Service Card

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,ASSICAL MUSIC OLIMOORS - World Radio History