MartinLogan Sequel II User's Manual · The Electrostatic Concept 5 History 6 Martin-Logan Exclusives 8 Operation 10 Room Acoustics 14 Placement 18 Questions 21 Troubleshooting 22

The Sequel II Speaker System

User's Manual

Page 2 Sequel II User's Manual

Introduction 3

Installation in Brief 4

The Electrostatic Concept 5

History 6

Martin-Logan Exclusives 8

Operation 10

Room Acoustics 14

Placement 18

Questions 21

Troubleshooting 22

Recommended Music 23

Glossary 24

Specifications 26

Notes 27

Important Contents

Your Sequel II speakers are provided with an automaticLimited 90 Day Warranty coverage.

You have the option, at no additional charge, toreceive Limited 3 Year Warranty coverage. To obtainLimited 3 Year Warranty coverage you need onlycomplete and return the Certificate of Registration thatwas included with your speakers to Martin-Logan,within 30 days of purchase.

Martin-Logan may not honor warranty serviceMartin-Logan may not honor warranty serviceMartin-Logan may not honor warranty serviceMartin-Logan may not honor warranty serviceMartin-Logan may not honor warranty serviceclaims unless we have a completed Warrantyclaims unless we have a completed Warrantyclaims unless we have a completed Warrantyclaims unless we have a completed Warrantyclaims unless we have a completed WarrantyRegistration card on file!Registration card on file!Registration card on file!Registration card on file!Registration card on file!

Should you be using your Martin-Logan product in acountry other than the one in which it was originallypurchased, we ask that you note the following:

1) The appointed Martin-Logan distributor for any givencountry is responsible for warranty servicing only onunits distributed by or through it in that country inaccordance with its applicable warranty.

2) Should a Martin-Logan product require servicing in acountry other than the one in which it was originallypurchased, the end user may seek to have repairsperformed by the nearest Martin-Logan distributor,subject to that distributor's local servicing policies,but all cost of repairs (parts, labor, transportation)must be born by the owner of the Martin-Loganproduct.

If you did not receive a Certificate of Registration withyour Sequel II speakers you cannot be assured ofhaving received new units. If this is the case, plea

Page 3Sequel II User's Manual

Introduction

Congratulations, you have invested in one of the world’spremier loudspeaker systems!

The Martin-Logan Sequel II represents the culmination of anintensive, dedicated group research program directedtoward establishing a world class reference monitorutilizing leading-edge technology, without compromisingdurability, reliability, craftsmanship, or aesthetic design.

The Sequel II begins where the original Sequel was andcarries that level of performance several steps beyond. Bassresponse now has better extension and improved definition,high frequency response also has better extension and ismuch more natural in character. Power handling andsystem efficiency have been enhanced as well.

Like the original Sequel, all materials in your new Sequel IIspeakers are of the highest quality to provide years ofenduring enjoyment and deepening respect. All trimpieces are constructed from selected hardwoods. They arethen grain and color matched and finally hand finished.The cabinetry is constructed from a special high-densityhardwood powderboard for structural integrity and isfinished with a durable and attractive suede paint.

Through rigorous testing, the curvilinear electrostatic panelhas proven itself to be one of the most durable and reliabletransducers available today. Fabricated from a custom

tooled, high-grade steel, the panel is then coated with aspecial polymer that is applied via a proprietary electro-static deposition process. This panel assembly houses amembrane 0.0005 of an inch thick! Ruggedly constructedand insulated, as much as 200 watts of continuous powerhas driven the Sequel II’s energized diaphragm intomassive excursions with no deleterious effects.

We know you are anxious to listen to your new speakers. So,to speed you along, we have provided an Installation inInstallation inInstallation inInstallation inInstallation inBriefBriefBriefBriefBrief section ahead of the detailed descriptive informationcontained in this manual.

Please read and follow these instructions as you initiallyconnect your Sequel II speakers into your system. Theseinstructions are important and will prevent you fromexperiencing any delay, frustration, or system damagewhich might occur in a trial-and-error procedure.

The other sections of your User’s ManualUser’s ManualUser’s ManualUser’s ManualUser’s Manual will explain indetail the operation of your Sequel II speakers and thephilosophy applied to their design. A clear understandingof your speakers will insure that you obtain maximumperformance and pleasure from this most exacting trans-ducer. It has been designed and constructed to give youyears of trouble-free listening enjoyment.

Happy Listening!


Installation in Brief

We know you are eager to hear yournew Sequel II loudspeakers, so thissection is provided to allow fast andeasy set up. Once you have themoperational, please take the time toread, in depth, the rest of the informa-tion in this manual. It will give youperspective on how to attain the bestpossible performance from this mostexacting transducer.

If you should experience any difficul-ties in the set-up or operation of yourSequel II speakers, please refer to theRoom Acoustics, PlacementRoom Acoustics, PlacementRoom Acoustics, PlacementRoom Acoustics, PlacementRoom Acoustics, Placement orOperationOperationOperationOperationOperation section of this manual.

Should you encounter a persistentproblem that cannot be resolved,please contact your AuthorizedMartin-Logan dealer. He will provideyou with the appropriate technicalanalysis to alleviate the situation.

Step 1: UnpackingStep 1: UnpackingStep 1: UnpackingStep 1: UnpackingStep 1: Unpacking

Remove your new Sequel II speakers from their packing.

Step 2: PlacementStep 2: PlacementStep 2: PlacementStep 2: PlacementStep 2: Placement

Place each SequeI Il at least two feet from any wall and angle them slightlytoward your listening area. This is a good place to start. Please see the Place-Place-Place-Place-Place-ment ment ment ment ment section of this manual for more details.

Step 3: PStep 3: PStep 3: PStep 3: PStep 3: Power Connection (Aower Connection (Aower Connection (Aower Connection (Aower Connection (AC)C)C)C)C)

Martin-Logan speakers require AC power to energize their electrostatic cells.Using the AC power cords provided, plug them in, making sure that you havemade a firm connection, first to the AC power receptacle on the rear panel of thespeaker and then to the wall outlet. Extension cords may be used, if necessary,since the power requirement of the Sequel II is extremely small.

Step 4: Signal ConnectionStep 4: Signal ConnectionStep 4: Signal ConnectionStep 4: Signal ConnectionStep 4: Signal Connection

Use the best speaker cables you can! Higher quality cables, available from yourspecialty dealer, are recommended and will give you superior performance! Spadeor banana connectors are suggested for optimum contact and ease of installation.

Attach your speaker cables to the Signal Input Signal Input Signal Input Signal Input Signal Input section on the rear panel. Beconsistent when connecting speaker leads to the terminals on the back of theSequel II: take great care to assign the same color to the (+) terminal on both theleft and right channels. If bass is nonexistent and you cannot discern a tight,coherent image, you may need to reverse the (+) and (-) leads on one side to bringthe system into proper polarity. For Bi-wiring/Passive Bi-amping instructions, turn tothe OperationsOperationsOperationsOperationsOperations section of this manual for proper set-up of the Sequel II system.

Step 5: Listen and EnjoyStep 5: Listen and EnjoyStep 5: Listen and EnjoyStep 5: Listen and EnjoyStep 5: Listen and Enjoy

Now, you may turn on your system and enjoy!

WARNING !WARNING !WARNING !WARNING !WARNING !Turn your amplifier off before making or breaking any signal

connections! The chassis is earth grounded and can present ashort circuit to your amplifier if contact is made!


The Electrostatic Concept

How can sound be reproduced by something that you areable to see through? Electrostatic energy makes this possible.

Where the world of traditional loudspeaker technologydeals with cones, domes, diaphrams and ribbons that aremoved with magnetism, the world of electrostatic loud-speakers deals with charged electrons attracting andrepelling each other.

To fully understand the electrostatic concept, somebackground information will be helpful. Remember whenyou learned, in a science or physics class, that like chargesrepel each other and opposite charges attract each other?

Magnet

An Electromagnetic TransducerAn Electromagnetic TransducerAn Electromagnetic TransducerAn Electromagnetic TransducerAn Electromagnetic Transducer

Surround ConeDust Cap

Voice Coil Former

Magnet Assembly

Magnetic GapVoice Coil

Basket Assembly

Figure 2.Figure 2.Figure 2.Figure 2.Figure 2. Cut away view of a typical moving coil driver.Notice the complexity due to the high number of parts.

major contributor to the sonic purity of the electrostaticconcept due to its exceptional linearity and low distortion.

Since the diaphragm of an electrostatic speaker isuniformly driven over its entire area, it can be extremelylight and flexible. This allows it to be very responsive totransients, thus perfectly tracing the music signal. As aresult, great delicacy, nuance and clarity is possible.When you look at the problems of traditional electromag-netic drivers, you can easily see why this is so beneficial.The cones and domes which are used in traditionalelectromagnetic drivers cannot be driven uniformlybecause of their design. Cones are driven only at the apex.

Spider

Domes are driven at theirperimeter. As a result, the restof the cone or dome is just"along for the ride". The veryconcept of these driversrequire that the cone or domebe perfectly rigid, dampedand massless. Unfortunatelythese conditions are notavailable in our world today.

To make these cones anddomes move, all electromag-netic drivers must use voicecoils wound on formers,spider assemblies, andsurrounds to keep the cone ordome in position (See Figure2). These pieces, whencombined with the high massof the cone or dome materi-als used, make it an ex-tremely complex unit withmany weaknesses andpotential for failure. Thesefaults contribute to the highdistortion products found inthese drivers and is atremendous disadvantagewhen you are trying tochange motion as quicklyand as accurately as aloudspeaker must (40,000times per second!).

Well, this principle is thefoundation of the electrostaticconcept.

An electrostatic transducerconsists of three pieces: thestators, the diaphragm and thespacers (See Figure 1). Thediaphragm is what actuallymoves to excite the air andcreate music. The stator's job isto remain stationary, hence theword stator, to provide areference point for the movingdiaphragm. The spacersprovide the diaphragm with afixed distance in which to movebetween the stators.

As your amplifier sends musicsignals to an electrostaticspeaker, these signals arechanged into two high-voltagesignals that are equal instrength but opposite inpolarity. These high voltagesignals are then applied to thestators. The resulting electro-static field, created by theopposing high voltage on thestators, works simultaneouslywith and against the dia-phragm, consequently movingit back and forth, producingmusic. This technique is knownas push-pull operation and is a

An Electrostatic TransducerAn Electrostatic TransducerAn Electrostatic TransducerAn Electrostatic TransducerAn Electrostatic Transducer

Stator

Spacer

Diaphragm

Figure 1Figure 1Figure 1Figure 1Figure 1. Cut away view of an electrostatic transducer.Notice the simplicity due to minimal parts usage.


History

In the late 1800’s, any loudspeaker was considered exotic.Today, most of us take the wonders of sound reproductionfor granted.

It was 1880 before Thomas Edison had invented the firstphonograph. This was a horn-loaded diaphragm that wasexcited by a playback stylus. In 1898, Sir Oliver Lodgeinvented a cone loudspeaker, which he referred to as a“bellowing telephone”, that was very similar to the conven-tional cone loudspeaker drivers that we know today.However, Lodge had no intention for his device to repro-duce music, because in 1898 there was no way to amplifyan electrical signal! As a result, his speaker had nothing tooffer over the acoustical gramophones of the period. It wasnot until 1906 that Dr. Lee DeForrest invented the triodevacuum tube. Before this , an electrical signal could not beamplified. The loudspeaker, as we know it today, shouldhave ensued then, but it did not. Amazingly, it was almosttwenty years before this would occur.

In 1921, the electrically cut phonograph record became areality. This method of recording was far superior to themechanically cut record and possessed almost 30 dB ofdynamic range. The acoustical gramophone couldn'tbegin to reproduce all of the information on this new disc.As a result, further developments in loudspeakers wereneeded to cope with this amazing new recording medium.

By 1923, Bell Telephone Laboratories made the decision todevelop a complete musical playback system consistingof an electronic phonograph and loudspeaker to takeadvantage of the new recording medium. Bell Labsassigned the project to two young engineers, C.W. Riceand E.W. Kellogg.

Rice and Kellogg had a well equipped laboratory at theirdisposal. This lab possessed a vacuum tube amplifier withan unheard of 200 watts, a large selection of the newelectrically cut phonograph records and a variety ofloudspeaker prototypes that Bell Labs had been collectingover the past decade. Among these were Lodge’s cone, aspeaker that used compressed air, a corona discharge(plasma) speaker, and an electrostatic speaker.

After a short time, Rice and Kellogg had narrowed the fieldof “contestants” down to the cone and the electrostat. Theoutcome would dictate the way that future generationswould refer to loudspeakers as being either “conventional”,or “exotic”.

Bell Laboratory’s electrostat was something to behold. Thisenormous bipolar speaker was as big as a door. Thediaphragm, which was beginning to rot, was made of themembrane of a pigs intestine that was covered with finegold leaf to conduct the audio signal.

When Rice and Kellogg began playing the new electri-cally cut records through the electrostat, they were shockedand impressed. The electrostat performed splendidly. Theyhad never heard instrumental timbres reproduced withsuch realism. This system sounded like real music ratherthan the honking, squawking rendition of the acousticgramophone. Immediately, they knew they were on tosomething big. The acoustic gramophone was destined tobecome obsolete.

Due to Rice and Kelloggs enthusiasm, they devoted aconsiderable amount of time researching the electrostaticdesign. However, they soon encountered the same difficul-ties that even present designers face; planar speakersrequire a very large surface area to reproduce the lowerfrequencies of the audio spectrum. Because the manage-ment at Bell Labs considered large speakers unaccept-able, Rice and Kelloggs work on electrostatics would neverbe put to use for a commercial product. Reluctantly, theyadvised the Bell management to go with the cone. For thenext thirty years the electrostatic design lay dormant.

During the Great Depression of the 1930's, consumer audioalmost died. The new electrically amplified loudspeakernever gained acceptance, as most people continued touse their old Victrola-style acoustic gramophones. Prior tothe end of World War II, consumer audio saw little, if any,progress. However, during the late 1940's, audio experi-enced a great rebirth. Suddenly there was tremendousinterest in audio products and with that, a great demandfor improved audio components. No sooner had the conebecome established than it was challenged by productsdeveloped during this new rebirth.


In 1947, Arthur Janszen, a young Naval engineer, took partin a research project for the Navy. The Navy was interestedin developing a better instrument for testing microphonearrays. The test instrument needed an extremely accuratespeaker, but Janszen found that the cone speakers of theperiod were too nonlinear in phase and amplituderesponse to meet his criteria. Janszen believed thatelectrostats were inherently more linear than cones, so hebuilt a model using a thin plastic diaphragm treated with aconductive coating. This model confirmed Janszen'sbeliefs, for it exhibited remarkable phase and amplitudelinearity.

Janszen was so excited with the results that he continuedresearch on the electrostatic speaker on his own time. Hesoon thought of insulating the stators to prevent the destruc-tive effects of arcing. By 1952 he had an electrostatictweeter element ready for commercial production. This newtweeter soon created a sensation among American audiohobbyists. Since Janszen's tweeter element was limited tohigh frequency reproduction, it often found itself used inconjunction with woofers, most notably, woofers fromAcoustic Research. These systems were highly regarded byall audio enthusiasts.

As good as these systems were, they would soon besurpassed by another electrostatic speaker.

In 1955, Peter Walker published three articles on electro-static loudspeaker design in Wireless World, a Britishelectronics magazine. In these articles Walker demon-strated the benefits of the electrostatic loudspeaker. Heexplained that electrostatics permit the use of diaphragmsthat are low in mass, large in area, and uniformly drivenover their surfaces by electrostatic forces. Due to thesecharacteristics, electrostats have the inherent ability toproduce a wide bandwidth, flat frequency response withdistortion products being no greater than the electronicsdriving them.

By 1956 Walker backed up his articles by introducing aconsumer product, the now famous Quad ESL. This speakerimmediately set a standard of performance for the audioindustry due to its incredible accuracy. However, in actualuse the Quad had a few problems. It could not play veryloud, it had poor bass performance, it presented a difficult

load that some amplifiers did not like, its dispersion wasvery directional, and its power handling was limited toaround 70 watts. As a result, many people continued to usebox speakers with cones.In the early 1960's Arthur Janszen joined forces with the KLHloudspeaker company and together they introduced theKLH 9. Due to the large size of the KLH 9, it did not have asmany limitations as the Quad. The KLH 9 could playmarkedly louder and lower in frequency than the Quad ESL.Thus a rivalry was born.

Janszen continued to develop electrostatic designs. Hewas instrumental in the design of the Koss Model One, theAcoustech, and the Dennesen speakers. Roger West, thechief designer of the JansZen Corporation became thepresident of Sound Lab. When JansZen Corporation wassold, the RTR loudspeaker company bought half of theproduction tooling. This tooling was used to make theelectrostatic panels for the Servostatic, a hybrid electro-static system that was Infinity's first speaker product. Othercompanies soon followed; each with their own uniqueapplications of the technology. These include Acoustat,Audiostatic, Beverage, Dayton Wright, Sound Lab, and Staxto name a few.

Electrostatic speakers have progressed and prosperedbecause they actually do what Peter Walker claimed theywould. The limitations and problems experienced in thepast were not inherent to the electrostatic concept. Theywere related to the applications of these concepts.

Today, these limitations have been addressed. Advance-ments in materials due to the U.S. space program givedesigners the ability to harness the superiority of theelectrostatic principle. Today's electrostats use advancedinsulation techniques or provide protection circuitry. Thepoor dispersion properties of early models have beenaddressed by using delay lines, acoustical lenses, multiplepanel arrays or, as in our own products, by curving thediaphragm. Power handling and sensitivity have beenincreased.

These developments allow the consumer the opportunity toown the highest performance loudspeaker products everbuilt. It's too bad Rice and Kellogg were never able to seejust how far the technology would be taken.


Martin-Logan Exclusives

Full Range OperationFull Range OperationFull Range OperationFull Range OperationFull Range Operation

The most significant advantage of Martin-Logan'sexclusive transducer technology reveals itself when youlook at examples of other loudspeaker products on themarket today.

The Sequel II uses no crossover networks above 250 Hzbecause they are not needed. The Sequel II consists of asingle, seamless electrostatic membrane reproducing allfrequencies above 250 Hz simultaneously. How is thispossible?

First we must understand that music is not composed ofseparate high, mid and lowfrequency pieces. In fact,music is comprised of a singlecomplex waveform with allfrequencies interactingsimultaneously.

The electrostatic transducer ofthe Sequel II essentially actsas an exact opposite of themicrophones used to recordthe original event. A micro-phone, which is a singleworking element, transformsacoustic energy into anelectrical signal that can beamplified or preserved bysome type of storage media.The Sequel II's electrostatictransducer transforms electri-cal energy from your amplifierinto acoustical energy.

Due to the limitations ofelectromagnetic drivers, nosingle unit can reproduce thefull range of frequencies.

Critical ZoneCritical ZoneCritical ZoneCritical ZoneCritical Zone250 - 20kHz250 - 20kHz250 - 20kHz250 - 20kHz250 - 20kHz

TweeterTweeterTweeterTweeterTweeter

MidrangeMidrangeMidrangeMidrangeMidrange

WooferWooferWooferWooferWoofer

Critical ZoneCritical ZoneCritical ZoneCritical ZoneCritical Zone250 - 20kHz250 - 20kHz250 - 20kHz250 - 20kHz250 - 20kHz

WooferWooferWooferWooferWoofer

Sequel IISequel IISequel IISequel IISequel IIE lectrostaticElectrostaticElectrostaticElectrostaticElectrostaticTransducerTransducerTransducerTransducerTransducer

Martin-Logan Sequel II Loudspeaker

Conventional Loudspeaker

Figure 1. Figure 1. Figure 1. Figure 1. Figure 1. Illustrates how a conventional speaker systemmust use a crossover network that has negative effectson the musical performance unlike the Sequel II which

needs no crossover networks in the "critical zone".

Instead, these drivers must be designed to operatewithin narrow, fixed bandwidths of the frequency rangeand then combined electrically so that the sum of theparts equals the total signal. While nice in theory, wemust deal with real-world conditions.

In order to use multiple drivers, a crossover network isenlisted to attempt a division of the complex musicalsignal into the separate pieces (usually highs, mids,and lows) that each specific driver was designed tohandle. Unfortunately, due to the phase relationshipsthat occur within all crossover networks and during the

acoustical recombinationprocess, nonlinearities andsevere degradation of themusic signal takes place inthe ear's most "critical zone"(See Figure 1).

The Sequel II's electrostatictransducer can single-handedly reproduce allfrequencies above 250 Hzsimultaneously. So you have,in one transducer, the abilityto handle, in elegant simplic-ity, the critical frequenciesabove 250 Hz.

The crossover phase disconti-nuities that are associatedwith traditional tweeter,midrange, and woofer systemsare eliminated. This results in adramatic improvement inimaging and staging perform-ance due to the minutelyaccurate phase relationshipof the full-range panel wavelaunch.


Vapor Deposited FilmVapor Deposited FilmVapor Deposited FilmVapor Deposited FilmVapor Deposited Film

The diaphragm material used in all Martin-Loganspeakers employs an extremely sophisticated conductivesurface that has been vapor deposited on the polymersurface at an atomic level. A proprietary compound isvaporized then electrostatically driven into the surface ofthe polymer film in a vacuum chamber. This processallows an optically transparent surface adding no massto the diaphragm that is extremely uniform in its surfaceresistivity characteristics. This uniform surface resistivitycontrols the electrostatic charge on the diaphragmsurface and regulates its migration. As a result, nodischarging or “arcing” can occur.

Transducer IntegrityTransducer IntegrityTransducer IntegrityTransducer IntegrityTransducer Integrity

All Martin-Logan transducers begin with two pieces ofhigh grade, cold rolled steel. These steel pieces are thencustom perforated and insulated with an exotic compos-ite coating. This proprietary coating insulates the stator to3 times its actual needed working voltage and gives theSequel II a wide margin of safe operation. In addition tothe electrical insulation properties, this coating alsoprovides the Sequel II with a durable, attractive finish thatdampens the steel to prevent ringing. These pieces arethen sandwiched with our exclusive vapor depositeddiaphragm and spacers into a curved geometry andbonded together with aerospace adhesives whosestrength exceeds that of welding.

The result of these advanced technologies is a trans-ducer that is attractive, durable, highly rigid, welldampened, and neutral.

Curvilinear Line SourceCurvilinear Line SourceCurvilinear Line SourceCurvilinear Line SourceCurvilinear Line Source

Since the beginning of Audio, achieving smooth disper-sion has long been a problem for all loudspeakerdesigners. Large panel transducers present even more ofa challenge because the larger the panel, the moredirectional the dispersion pattern becomes.

Full range electrostats have long been one of the mostproblematic transducers because they attain their fullrange capabilities via a large surface area. It looked asif they were in direct conflict to smooth dispersion andalmost every attempt to correct this resulted in either poordispersion or a serious compromise in sound quality.

After extensive research, Martin-Logan engineers discov-ered an elegantly simple solution to achieve a smoothpattern of dispersion without degrading sound quality. Bycurving the horizontal plane of the electrostatic trans-ducer, a controlled horizontal dispersion pattern couldbe achieved, yet the purity of the almost masslesselectrostatic diaphragm remained uncompromised. Aftercreating this technology, Martin-Logan developed theproduction capability to bring this technology out of thelaboratory and into the market place.

You will find this proprietary Martin-Logan technologyused in all of our products. It is one of the many reasonsbehind our reputation for high quality sound withpractical usability. This is also why you see the unique"see through" cylindrical shape of all Martin-Loganproducts.


Operation

Signal ConnectionSignal ConnectionSignal ConnectionSignal ConnectionSignal Connection

Use the best speaker cables you can! The length and typeof speaker cable used in your system will have an audibleeffect. Under no circumstance should a wire of gaugehigher (thinner) than #16 be used. In general, the longerthe length used, the greater the necessity of a lower gauge,and the lower the gauge, the better the sound, withdiminishing returns setting in around #8 to #12.

A variety of speaker cables are now available whosemanufacturers claim better performance than with stan-dard heavy gauge wire. We have verified this in somecases, and the improvements available are often morenoticeable than the differences between wires of differentgauge.

We would also recommend, if possible, that short runs ofspeaker cable connect the power amplifier(s) and speak-ers and that high quality long interconnect cables be usedto connect the preamplifier and power amplifier. This resultsin the power amplifiers being close to the speakers, whichmay be practically or cosmetically difficult, but if the lengthof the speaker cables can be reduced to a few meters,sonic advantages may be obtained. The effects of cablesmay be masked if the equipment is not of the highestquality.

Connections are done at the Signal InputSignal InputSignal InputSignal InputSignal Input section on therear electronics panel of the Sequel II. Use spade orbanana connectors for optimum contact and ease ofinstallation. Make certain that all your connections are tightand positive.

Be consistent when connecting the speaker cables to theSignal InputSignal InputSignal InputSignal InputSignal Input terminals. Take care to assign the samecolor cable lead to the (+) terminal on both the left andright channel speakers. If bass is nonexistent and youcannot discern a tight, coherent image, you may need toreverse the (+) and (-) leads on one speaker to bring thesystem into proper polarity.

AC Power ConnectionAC Power ConnectionAC Power ConnectionAC Power ConnectionAC Power Connection

Because your Martin-Logan Sequel II's use an internal powersupply to energize their electrostatic cells with high-voltageDC, they must be connected to an AC power source. For thisreason they are provided with the proper IEC standard powercords. These cords should be firmly inserted into the AC powerreceptacles on the rear connection panel of the speakers,then to any convenient AC wall outlet. Extension cords may beused, if necessary, since the AC power requirement of thespeaker is extremely small (less than 2.5 watts). The Sequel II'shave been designed to remain on continuously and shouldremain connected to a continuous AC power source. Asmentioned earlier, power consumption of the Sequel II's is verysmall and the life expectancy of its components will not bereduced by continuous operation.

The power cord should not be installed, removed, orleft detached from the speaker while the other end is

connected to an AC power source.

Your Sequel II speakers are wired for the power servicesupplied in the country of original consumer sale. The ACpower rating applicable to a particular unit is specifiedboth on the packing carton and on the serial number plateattached to the speaker.

If you remove your Sequel II speakers from the country oforiginal sale, be certain that AC power supplied in anysubsequent location is suitable before connecting andoperating the speakers. Substantially impaired perform-ance or severe damage may occur to a Sequel II speaker ifoperation is attempted from an incorrect AC power source.

If your home is not equipped with three-prong wall outlets,you may use “cheater” plugs to connect the speakers to ACpower. These may be obtained at your dealer or anyhardware department.


Figure 1Figure 1Figure 1Figure 1Figure 1. Standard Connection. One channel shown.

Figure 2.Figure 2.Figure 2.Figure 2.Figure 2. Bi-Wire Connection. One channel shown.

Warning!Warning!Warning!Warning!Warning!Turn your amplifier off before making orbreaking any signal connections! Thechassis is earth grounded and can

present a short circuit to your amplifier ifcontact is made!

Standard ConnectionStandard ConnectionStandard ConnectionStandard ConnectionStandard Connection

Please take note of the jumper clips installedunder the 5-way binding posts. These clipsattach the high and low frequency sectionsof the crossover together. Leaving these inplace, connect the (+) wire from youramplifier to either Red binding post and the(-) wire from your amplifier to either Blackbinding post (See Figure 1).

Bi-Wire ConnectionBi-Wire ConnectionBi-Wire ConnectionBi-Wire ConnectionBi-Wire Connection

This method of connection replaces thejumper clips installed under the 5-waybinding posts with individual runs of speakerwire from your amplifier. This doubles thesignal carrying conductors from the audioamplifier to the speaker, thus direct-couplingeach portion of the crossover to the amplifier.

To bi-wire you must first loosen the 5-wayirst loosen the 5-wayirst loosen the 5-wayirst loosen the 5-wayirst loosen the 5-waybinding posts and remove the jumperbinding posts and remove the jumperbinding posts and remove the jumperbinding posts and remove the jumperbinding posts and remove the jumperclipsclipsclipsclipsclips. Connect one set of wires to the HI+HI+HI+HI+HI+and HI-HI-HI-HI-HI- binding posts of the Sequel II. Thenconnect a second set of wires to the LO+LO+LO+LO+LO+and LO-LO-LO-LO-LO- binding posts. Next, connect bothsets of wires to the appropriate terminals onyour amplifier. Please take care to connectboth (+) wires to the (+) amplifier terminalsand both (-) wires to the (-) amplifier terminals.This is known as a parallel connection (SeeFigure 2).


Operation

Figure 3. Horizontal Passive Bi-amplification. One channel shown.

Passive Bi-AmplificationPassive Bi-AmplificationPassive Bi-AmplificationPassive Bi-AmplificationPassive Bi-Amplification

For those of you that desire ultimate perfor-mance, the Sequel II may be passively bi-amplified using the existing internal passivecrossover elements.

WARNING!WARNING!WARNING!WARNING!WARNING!Only after the jumper clips are removed

may you connect individual runs of speakercable from your amplifiers to the High-passand Low-pass Signal Input binding posts.Damage will occur to your amplifiers if the

jumper clips are not removed!

This method takes the bi-wiring concept onestep further. Now you will have a dedicatedchannel of amplification directly connectedto the high and low pass sections of theSequel II crossover. There are two differentmethods for bi-amping with two stereoamplifiers. The first and most common isreferred to as Horizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-amping. The second methodis referred to as Vertical Bi-ampingVertical Bi-ampingVertical Bi-ampingVertical Bi-ampingVertical Bi-amping. With either methodyou may use two stereo amplifiers or four mono amplifiers, ortwo mono amplifiers and one stereo amplifier. Get theidea? With either form of passive bi-amplification, your pre-amplifier must have dual outputs. If your pre-amplifier is notso equipped, you must either purchase or construct a "Y"adaptor.

Horizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-amping allows you to use two differenttypes, models or brands of amplifiers (i.e. tubes on top,transistor on the bottom). However, we recommend that youuse two identical amplifiers (i.e. same brand and model). Ifyou must use two different amplifiers, it is essential that they

have the same gain or that one of the two have adjustablegain so that you can match their gain characteristics. If theamplifiers of choice do not have the same gain character-istics, then a sonic imbalance will occur.

With Horizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-ampingHorizontal Bi-amping, one amplifier drives the highpass section while the second amplifier drives the low passsection. To Horizontally Bi-ampHorizontally Bi-ampHorizontally Bi-ampHorizontally Bi-ampHorizontally Bi-amp your Sequel II's you mustloosen the 5-way binding posts and remove the jumper clips.Connect the low frequency amplifier to the LO+LO+LO+LO+LO+ and LO-LO-LO-LO-LO-binding posts of both speakers. Connect the high frequencyamplifier to the HI+HI+HI+HI+HI+ and HI-HI-HI-HI-HI- binding posts. Next connect theleft and right preamplifier outputs to the appropriate left andright inputs of both amplifiers (See Figure 3).


Bass Control SwitchBass Control SwitchBass Control SwitchBass Control SwitchBass Control Switch

On the rear panel of the Sequel II electronicsmodule, below the Signal InputSignal InputSignal InputSignal InputSignal Input, is a twoposition Bass Control Bass Control Bass Control Bass Control Bass Control switch that allowsyou to select the type of low frequencyresponse you desire.

The 0 dB0 dB0 dB0 dB0 dB position is considered the normalsetting for most rooms. However, if you feelthat the bass in your system is too lightrelative to the mid and high frequencies,simply select the +2dB+2dB+2dB+2dB+2dB position. This switchposition will increase the output of the wooferby 2dB.

Some experimentation with these two switchsettings will allow you to find the optimaltonal balance for your specific taste, roomand equipment. Below is a graph showinghow the +2dB switch setting affects thefrequency response of the Sequel II.

The very nature of Vertical Bi-amping Vertical Bi-amping Vertical Bi-amping Vertical Bi-amping Vertical Bi-amping dictates that bothamplifiers be identical. With Vertical Bi-ampingVertical Bi-ampingVertical Bi-ampingVertical Bi-ampingVertical Bi-amping, each ofthe stereo amplifiers is dedicated to one speaker. Forinstance, the left channel of each amplifier drives the lowpass section while the right channel drives the high passsection. To Vertically Bi-ampVertically Bi-ampVertically Bi-ampVertically Bi-ampVertically Bi-amp your Sequel II's you mustloosen the 5-way binding posts and remove the jumperclips from both speakers. Starting with one speaker,connect the left channel to the LO+LO+LO+LO+LO+ and LO-LO-LO-LO-LO- binding postsand the right channel to the HI+HI+HI+HI+HI+ and HI-HI-HI-HI-HI- binding posts.Repeat the same procedure for the other speaker. Connectthe left preamplifier outputs to both inputs of the leftchannel amplifier and the right preamplifier outputs to bothinputs of the right channel speaker (See Figure 4).

20Hz 50Hz 80Hz 160Hz 250Hz

+2dB

Effects of the Bass Control switch

Figure 4. Vertical Passive Bi-amplification. One channel shown.


YYYYYour Rour Rour Rour Rour Roomoomoomoomoom

This is one of those areas that requires both a littlebackground to understand and some time and experi-mentation to attain the best performance from yoursystem.

Your room is actually a component and an importantpart of your system. This component is a very largevariable and can dramatically add to, or subtract from,a great musical experience.

All sound is composed of waves. Each note has its ownwave size, with the lower bass notes literally encompass-ing from 10' to as much as 40'! Your room participates in

this wave experience like a 3 dimensional pool withwaves reflecting and becoming enhanced dependingon the size of the room and the types of surfaces in theroom.

Remember, your audio system can literally generate allof the information required to recreate a musical event intime, space, and tonal balance. The purpose of yourroom, ideally, is to not contribute to that information.However, every room does contribute to the sound andthe better speaker manufacturers have designed theirsystems to accommodate this phenomenon.

TTTTTerminologyerminologyerminologyerminologyerminology

Standing WavesStanding WavesStanding WavesStanding WavesStanding Waves. The parallel walls in your room willreinforce certain notes to the point that they willsound louder than the rest of the audio spectrumand cause “one note bass”, “boomy bass” or “tubbybass”. For instance, 100Hz represents a 10' wave-length. Your room will reinforce that specificfrequency if one of the dominant dimensions is 10'.Large objects in the room such as cabinetry orfurniture can help to minimize this potential problem.Some serious “audiophiles” will literally build aspecial room with no parallel walls just to get awayfrom this phenomenon.

Reflective Surfaces (near-field reflections)Reflective Surfaces (near-field reflections)Reflective Surfaces (near-field reflections)Reflective Surfaces (near-field reflections)Reflective Surfaces (near-field reflections) . Thehard surfaces of your room, particularly if close toyour speaker system, will reflect those waves backinto the room over and over again, confusing theclarity and imaging of your system. The smallersound waves are mostly affected here and occur inthe mid and high frequencies. This is where voiceand frequencies as high as the cymbals can occur.

Resonant Surfaces and ObjectsResonant Surfaces and ObjectsResonant Surfaces and ObjectsResonant Surfaces and ObjectsResonant Surfaces and Objects. All of the surfacesand objects in your room are subject to the frequen-cies generated by your system. Much like aninstrument, they will vibrate and “carry on” insyncopation with the music and contribute in anegative way to the music. Ringing, boominess, andeven brightness can occur simply because they are“singing along” with your music.

Resonant CavitiesResonant CavitiesResonant CavitiesResonant CavitiesResonant Cavities. Small alcoves or closet type areasin your room can be chambers that create their own“standing waves” and can drum their own “onenote” sounds.

Clap your hands. Can you hear an instant echo respondback? You have near-field reflections. Stomp your foot onthe floor. Can you hear a “boom”? You have standingwaves or large panel resonances such as a poorlysupported wall. Put your head in a small cavity area andtalk loudly. Can you hear a booming? You’ve justexperienced a cavity resonance.

Room Acoustics


Rules of ThumbRules of ThumbRules of ThumbRules of ThumbRules of Thumb

Hard vs. Soft SurfacesHard vs. Soft SurfacesHard vs. Soft SurfacesHard vs. Soft SurfacesHard vs. Soft Surfaces. If the front or back wall of yourlistening room is soft, it may benefit you to have ahard or reflective wall in opposition. As well, theceiling and floor should follow the same basicguideline. However, the side walls should be roughlythe same in order to deliver a focused image.

This rule suggests that a little reflection is good. As amatter of fact, some rooms can be so “over damped”with carpeting, drapes and sound absorbers that themusic system can sound dull and lifeless. On theother hand, rooms can be so hard that the systemcan sound like a gymnasium with too much reflec-tion and brightness. The point is that balance is theoptimum environment.

Break-up ObjectsBreak-up ObjectsBreak-up ObjectsBreak-up ObjectsBreak-up Objects. Objects with complex shapes, suchas bookshelves, cabinetry, and multiple shapedwalls can help break up those sonic gremlins anddiffuse any dominant frequencies.

Solid CouplingSolid CouplingSolid CouplingSolid CouplingSolid Coupling. Your loudspeaker system generatesfrequency vibrations or waves into the room. This ishow it creates sound. Those vibrations will vary from20 per second to 20,000 per second. If your speakersystem is not securely planted on the floor or solidsurface, it can shake as it produces sound and,consequently, the sound can be compromised. Ifyour speaker is sitting on the carpet and only footgliders are used, the bass can be ill defined andeven boomy. The use of spikes is recommended toinsure secured footing for your speakers.

Bipolar SpeakBipolar SpeakBipolar SpeakBipolar SpeakBipolar Speakers and Yers and Yers and Yers and Yers and Your Rour Rour Rour Rour Roomoomoomoomoom

Martin-Logan electrostatic loudspeakers are known asbipolar radiators. This means that they produce soundfrom both their fronts and their backs. Consequently,musical information is reflected by the wall behind themand may arrive either in or out of step with the informationproduced by the front of the speaker.

The low frequencies can either be enhanced or nulledby the position from the front wall. Your Sequel II's havebeen designed to be placed 2 to 3 feet from the frontwall (the wall in front of the listening position) to obtainthe best results, however your room may see thingsdifferently. So, listening to the difference of the bassresponse as a result of the changes in distance from thefront wall can allow you to get the best combination ofdepth of bass and tonal balance.

Now that you know about Reflective SurfacesReflective SurfacesReflective SurfacesReflective SurfacesReflective Surfaces andResonant ObjectsResonant ObjectsResonant ObjectsResonant ObjectsResonant Objects, you can see how the mid-rangeand high frequencies can be affected. The timing of thefirst wave as it is first radiated to your ears and then thereflected information as it arrives at your ears later in time,can result in confusion of the precious timing informationthat carries the clues to imaging and, consequently resultin blurred imaging and excessive brightness. Soft walls,curtains, wall hangings, or sound dampeners (yourdealer can give you good information here) can beeffective if these negative conditions occur.


Controlled Horizontal DispersionControlled Horizontal DispersionControlled Horizontal DispersionControlled Horizontal DispersionControlled Horizontal Dispersion

Your Sequel II's launch a 30 degree dispersion patternwhen viewed from above. This horizontal dispersion fieldgives a choice of good seats for the performance whileminimizing interactions with side walls (See Figure 1).

Make sure both speakers stand exactly at the samevertical angle, otherwise the image can be skewed orpoorly defined. The wave launch of both speakers isextremely accurate in both the time and spectral domainand, consequently, small refined adjustments can resultin noticeable sonic improvements.

Controlled Vertical DispersionControlled Vertical DispersionControlled Vertical DispersionControlled Vertical DispersionControlled Vertical Dispersion

As you can see from the illustrations, your Sequel IIspeakers project a controlled dispersion pattern. EachSequel II is a four foot line source beginning two feetabove floor level (See Figure 2). This vertical dispersionprofile minimizes interactions with the floor and theceiling.

Figure 1Figure 1Figure 1Figure 1Figure 1. Martin-Logan Sequel II's deliver a 30 degree wavelaunch dispersion pattern distributed horizontally.

Figure 2Figure 2Figure 2Figure 2Figure 2. Your Sequel II speaker system is a 4 foot linesource when viewed vertically. Actual height above the flooris from two to six feet.

Room Acoustics and Dispersion Interactions


Three Major TThree Major TThree Major TThree Major TThree Major Types of Dispersionypes of Dispersionypes of Dispersionypes of Dispersionypes of Dispersion

In the field of loudspeaker design, it is a known fact thatas the sound wave becomes progressively smaller thanthe transducer producing it, the dispersion of that wavebecomes more and more narrow, or directional. This factoccurs as long as the transducer is a flat surface. Largeflat panel speakers exhibit venetian blindvenetian blindvenetian blindvenetian blindvenetian blind effects dueto this phenomenon. This is why most manufacturers optfor small drivers (i.e. tweeters and midrange) to approxi-mate what is known as a point sourcepoint sourcepoint sourcepoint sourcepoint source wave launch.

Historically, most attempts to achieve smooth dispersionfrom large flat panel transducers resulted in trade-offs.After exhaustive testing of these different solution at-tempts, we found an elegantly simple, yet very difficult toexecute solution. By curving the radiating surface, wecreate the effect of a horizontal arc. This allows theengineers at Martin-Logan to control the high frequencydispersion pattern of our transducers. That is why you seethe gentle curve on our products.

A controlled 30-degree cylindri-cal wave-front, which is a Martin-Martin-Martin-Martin-Martin-Logan exclusiveLogan exclusiveLogan exclusiveLogan exclusiveLogan exclusive, offers optimalsound distribution with minimalroom interaction. The result is solidimaging with a wide listening area.

Even though they suffer from "vene-tian blind" effect, angled multiplepanel speakers can deliver goodimaging, but only to specific spotsin the listening area.

As can be seen, point source con-cepts invite a great deal of roominteraction. While delivering goodfrequency response to a large lis-tening audience, imaging is con-sequently confused and blurred.


Listening PListening PListening PListening PListening Positionositionositionositionosition

By now your speakers should be placed approximately 2to 3 feet from the front wall (wall in front of the listeningposition) and at least 1 to 2 feet from the side walls. Yoursitting distance should be further than the distancebetween the speakers themselves. What you are trying toattain is the impression of good center imaging andstage width.

There is no exact distance between speakers andlistener, but there is a relationship. In long rooms, natu-rally, that relationship changes. The distance betweenthe speakers will be far less than the distance from you tothe speaker system. However, in a wide room you will stillfind that if the distance from the listener to the speakersbecomes smaller than the distance between the speak-ers themselves, the image will no longer focus in thecenter.

Now that you have positioned your speaker system,spend some time listening. Wait to make any majorchanges in your initial set-up for the next few days as thespeaker system itself will change subtly in its sound. Overthe first 20 hours of play the actual tonal quality willchange slightly with deeper bass and more spacioushighs resulting.

After a few days of listening you can begin to makerefinements and hear the differences of those refinements.

The WThe WThe WThe WThe Wall Behind the Listenerall Behind the Listenerall Behind the Listenerall Behind the Listenerall Behind the Listener

Near-field reflections can also occur from your back wall(the wall behind the listening position). If your listeningposition is close to the back wall, these reflections cancause problems and confuse the quality of imaging.Actually it is better for the wall behind you to be soft thanto be bright. If you have a hard back wall and yourlistening position is close to it, experiment with devicesthat will soften and absorb information (i.e. wall hang-ings and possibly even sound absorbing panels).

The WThe WThe WThe WThe Wall Behind the Speakall Behind the Speakall Behind the Speakall Behind the Speakall Behind the Speakersersersersers

The front wall (the wall behind your speakers), should notbe extremely hard or soft. For instance, a pane of glasswill cause reflections, brightness, and confused imaging.Curtains, drapery and objects such as bookshelving canbe placed along the wall to tame an extremely hardsurface. A standard sheet rock or textured wall is gener-ally an adequate surface if the rest of the room is not toobright and hard.

Sometimes walls can be too soft. If the entire front wallconsists of only heavy drapery, your system can literallysound too soft or dull. You may hear dull, muted musicwith little ambience. Harder room surfaces will actuallyhelp in this case.

The front surface should, optimally, be one long wallwithout any doors or openings. If you have openings, thereflection and bass characteristics from one channel tothe other can be different.

The Side WThe Side WThe Side WThe Side WThe Side Wallsallsallsallsalls

The same requirements exist for side walls. Additionally, agood rule of thumb is to have the side walls as far awayfrom the speaker sides as possible, minimizing near fieldside wall reflections. Sometimes, if the system is bright orthe imaging is not to your liking, and the side walls arevery near, try putting curtains or softening materialdirectly to the edge of each speaker. An ideal side wall,however, is no side wall at all.

Placement


ExperimentationExperimentationExperimentationExperimentationExperimentation

Toe-inToe-inToe-inToe-inToe-in. Now you can begin to experiment. First begin bytoeing your speakers in towards the listening areaand then toeing them straight into the room. You willnotice that the tonal balance changes ever soslightly. You will also notice the imaging changing.Generally it is found that the ideal listening position iswith the speakers slightly toed-inslightly toed-inslightly toed-inslightly toed-inslightly toed-in so that you arelistening to the inner third of the curved transducersection.

Experimenting with the toe-in will help in terms of tonalbalance. You will notice that as the speakers aretoed-out, the system becomes slightly brighter thanwhen toed-in. This design gives you the flexibility tomodify a soft or bright room.

Tilting the Speakers Backwards and Forwards.Tilting the Speakers Backwards and Forwards.Tilting the Speakers Backwards and Forwards.Tilting the Speakers Backwards and Forwards.Tilting the Speakers Backwards and Forwards. Ascan be seen from the diagrams in the Room Acous-Room Acous-Room Acous-Room Acous-Room Acous-tics tics tics tics tics section of this manual, the vertical dispersion isdirectional above and below the stator panel itself. Insome instances, if you are sitting close to the floor,slight forward tilting of the speakers can enhanceclarity and precision.

Imaging. Imaging. Imaging. Imaging. Imaging. In their final location, your Sequel II's shouldhave a stage width somewhat wider than thespeakers themselves. On well recorded music, theinstruments should extend beyond the edges of eachspeaker to the left and to the right, yet a vocalistshould appear directly in the middle. The size of theinstrumentsshould be neither too large nor too small. Additionally,you should find good clues as to stage depth. Makesure, when listening, that the vertical alignment,distance from the front wall, and toe in is exactly thesame from one speaker to the other. This will greatlyenhance the quality of your imaging.

Bass Response. Bass Response. Bass Response. Bass Response. Bass Response. Your bass response should neither beone note nor should it be too heavy. It should extendfairly deep to even the deepest organ passages, yet itshould be tight and well defined. Kick-drums shouldbe tight and percussive, string bass notes should beuniform and consistent throughout the entirety of therun without any booming or thudding.

Tonal Balance.Tonal Balance.Tonal Balance.Tonal Balance.Tonal Balance. Voices should be natural and full,cymbals should be detailed and articulate yet notbright and piercing, pianos should have a nicetransient characteristic and deep tonal registers aswell. If you cannot attain these virtues, re-read thesection on Room AcousticsRoom AcousticsRoom AcousticsRoom AcousticsRoom Acoustics. This will give you clueson how to get closer to those ideal virtues.

A FA FA FA FA Final Winal Winal Winal Winal Wordordordordord

Final Placement.Final Placement.Final Placement.Final Placement.Final Placement.After obtaining good wall treatments and attainingproper angle, begin to experiment with the distance fromthe wall behind the speakers. Move your speaker slightlyforward into the room. What happened to the bassresponse? What happened to the imaging? If theimaging is more open and spacious and the bassresponse tightened, that is a superior position. Move thespeakers back six inches from the initial set-up position.Again, listen to the imaging and bass response. Therewill be a position where you will have pin-point imagingand good bass response. That position becomes thepoint of the optimal placement from the front wall.

Now experiment with placing the speakers farther apart.As the speakers are positioned farther apart, listen again,not so much for bass response but for stage width andgood pin-point focusing.

Your ideal listening position and speaker position will bedetermined by:

1) tightness and extension of bass response,1) tightness and extension of bass response,1) tightness and extension of bass response,1) tightness and extension of bass response,1) tightness and extension of bass response,2) the width of the stage, and2) the width of the stage, and2) the width of the stage, and2) the width of the stage, and2) the width of the stage, and3) the pin-point focusing of imaging3) the pin-point focusing of imaging3) the pin-point focusing of imaging3) the pin-point focusing of imaging3) the pin-point focusing of imaging.

Once you have found the best of all three of thoseconsiderations, you will have your best speaker location.


The XThe XThe XThe XThe X-tra “-tra “-tra “-tra “-tra “TTTTTweek”week”week”week”week”

A major cable company developed the followingprocedure for speaker placement. As a final test of exactplacement, use these measurements for your speakersplacement, and see what can happen to the ultimateenhancement of your system’s performance.

The procedure consists of two basic measurements:

1) distance from the front wall (wall in front of thelistening position) to the center of the curvilineartransducer.

To determine distance from the front wall, measure theheight of your ceiling (inches) and multiply the figure by.618 (i.e. ceiling height in inches X .618 = distance fromthe front wall to the center of the curvilinear transducer).

2) distance from the side-walls to the center of thecurvilinear transducer.

To determine distance from the side-walls, measure thewidth of your room (inches) and divide the figure by 18,next multiply the quotient by 5 (i.e. (room width in inches/18) X 5 = distance from the side-walls to the center of thecurvilinear transducer).

These two formulas will determine optimum placement ofyour speakers to minimize standing waves.

Solid FSolid FSolid FSolid FSolid Footingootingootingootingooting

After living and experimenting with your Sequel II's, youwill then want to use the spikes included in your ownerskit. The Sequel II will become more firmly planted on thefloor and, consequently, bass will tighten and imagingwill become more coherent and detailed. It is best not toimplement the spikes, however, until you are secure in thepositioning as the spikes can damage the floors if thespeaker is moved.

Enjoy YEnjoy YEnjoy YEnjoy YEnjoy Yourselfourselfourselfourselfourself

The Sequel II is a very refined speaker and, as such,benefits from care in set-up. With these tips in mind, youwill find, over your months of listening, that small changescan result in demonstrable differences. As you live withyour speakers, do not be afraid to experiment with theirpositioning until you find the optimal relationshipbetween your room and your speaker system to give youthe best results. Your efforts will be rewarded.

You are now armed with the fundamentals of roomacoustics and the specific fundamentals of the Sequel IIloudspeaker. Happy listening!

Placement


Questions

What size amplifier should I use with the SequelWhat size amplifier should I use with the SequelWhat size amplifier should I use with the SequelWhat size amplifier should I use with the SequelWhat size amplifier should I use with the SequelI I ' s ?I I ' s ?I I ' s ?I I ' s ?I I ' s ?

We recommend an amplifier with 100 to 200 watts perchannel for most applications. The Sequel II will performwell with either a tube or transistor amplifier, and willreveal the sonic character of either type.

Do I need an amplifier with high current capa-Do I need an amplifier with high current capa-Do I need an amplifier with high current capa-Do I need an amplifier with high current capa-Do I need an amplifier with high current capa-bi l i ty?bi l i ty?bi l i ty?bi l i ty?bi l i ty?

No. The Sequel II's impedance characteristics do notrequire that a high current amplifier be used. However,it is important that the amplifier be stable operating intovarying impedance loads.

Should I unplug my Sequel II's during a thun-Should I unplug my Sequel II's during a thun-Should I unplug my Sequel II's during a thun-Should I unplug my Sequel II's during a thun-Should I unplug my Sequel II's during a thun-derstorm?derstorm?derstorm?derstorm?derstorm?

Yes. Or before. It’s a good idea to disconnect all of youraudio/video components during stormy weather.

Is there likely to be any interaction between theIs there likely to be any interaction between theIs there likely to be any interaction between theIs there likely to be any interaction between theIs there likely to be any interaction between theSequel II's and the television in my Audio/VideoSequel II's and the television in my Audio/VideoSequel II's and the television in my Audio/VideoSequel II's and the television in my Audio/VideoSequel II's and the television in my Audio/Videosys tem?sys tem?sys tem?sys tem?sys tem?

Actually, there is less interaction between a televisionand an electrostatic speaker than between a televisionand a conventional system. The magnets in conventionalspeakers do interact with televisions tubes. However, wedo recommend that you keep your speakers at least onefoot away from the television because of the dynamicwoofer they employ.

Will my electric bill go ‘sky high’ by leaving myWill my electric bill go ‘sky high’ by leaving myWill my electric bill go ‘sky high’ by leaving myWill my electric bill go ‘sky high’ by leaving myWill my electric bill go ‘sky high’ by leaving myspeakers plugged in all the time?speakers plugged in all the time?speakers plugged in all the time?speakers plugged in all the time?speakers plugged in all the time?

No. A pair of Sequel II's draw about 5 watts maximum.

Could my children, pets, or myself be shockedCould my children, pets, or myself be shockedCould my children, pets, or myself be shockedCould my children, pets, or myself be shockedCould my children, pets, or myself be shockedby the high-voltage present in the electrostaticby the high-voltage present in the electrostaticby the high-voltage present in the electrostaticby the high-voltage present in the electrostaticby the high-voltage present in the electrostaticpanel?panel?panel?panel?panel?

No. High voltage with low current is not dangerous. As amatter of fact, the voltage in our speakers is 10 times lessthan the static electricity that builds up on the surface ofyour television screen.

If my child punctured the diaphragm with aIf my child punctured the diaphragm with aIf my child punctured the diaphragm with aIf my child punctured the diaphragm with aIf my child punctured the diaphragm with apencil, stick, or similar item, how extensivepencil, stick, or similar item, how extensivepencil, stick, or similar item, how extensivepencil, stick, or similar item, how extensivepencil, stick, or similar item, how extensivewould the damage to the speaker be?would the damage to the speaker be?would the damage to the speaker be?would the damage to the speaker be?would the damage to the speaker be?

Our research department has literally punctured hun-dreds of holes in a diaphragm, neither affecting thequality of the sound nor causing the diaphragm to rip.However, you will be able to see the actual puncture andit can be a physical nuisance. If this is the case, replac-ing the electrostatic transducer will be the only solution.

Will exposure to sunlight affect the life or per-Will exposure to sunlight affect the life or per-Will exposure to sunlight affect the life or per-Will exposure to sunlight affect the life or per-Will exposure to sunlight affect the life or per-formance of the Sequel II?formance of the Sequel II?formance of the Sequel II?formance of the Sequel II?formance of the Sequel II?

We recommend that you not place your Sequel II's indirect sunlight as the ultraviolet (UV) rays from the sun cancause deterioration of grill cloth, speaker cones, etc.However, small exposures to UV will not cause a problem.

Will excessive smoke or dust cause any prob-Will excessive smoke or dust cause any prob-Will excessive smoke or dust cause any prob-Will excessive smoke or dust cause any prob-Will excessive smoke or dust cause any prob-lems?lems?lems?lems?lems?

Exposure to excessive contaminants, such as smoke ordust, may potentially affect the performance of theelectrostatic membrane and may cause discoloration ofthe diaphragm membrane. When not in use for extendedperiods, you should unplug the speakers and cover themwith the plastic bags they were originally packed in.


Troubleshooting

Poor ImagingPoor ImagingPoor ImagingPoor ImagingPoor Imaging

Check placement. Are both speakers the same dis-tance from the walls? Do they have the same amount oftoe-in? Try moving the speakers away from the backand side walls.

Check the polarity of the speaker wires. Are they con-nected properly?

Popping and Ticking Sounds, Funny NoisesPopping and Ticking Sounds, Funny NoisesPopping and Ticking Sounds, Funny NoisesPopping and Ticking Sounds, Funny NoisesPopping and Ticking Sounds, Funny Noises

These occasional noises are harmless and will nut hurtyour audio system or your speakers. All electrostaticspeakers are guilty of making odd noises at one time oranother.

These noises may be caused by dirt and dust particlescollecting on the speaker, by high humidity or by ACline fluctuations that may occur in your area.

Dirt and dust may be vacuumed off with a brushattachment connected to your vacuum cleaner or youmay blow them off with compressed air.

DO NOT SPRAY ANY KIND OF CLEANING AGENTDO NOT SPRAY ANY KIND OF CLEANING AGENTDO NOT SPRAY ANY KIND OF CLEANING AGENTDO NOT SPRAY ANY KIND OF CLEANING AGENTDO NOT SPRAY ANY KIND OF CLEANING AGENTON OR IN CLOSE PROXIMITY TO THE ELECTRO-ON OR IN CLOSE PROXIMITY TO THE ELECTRO-ON OR IN CLOSE PROXIMITY TO THE ELECTRO-ON OR IN CLOSE PROXIMITY TO THE ELECTRO-ON OR IN CLOSE PROXIMITY TO THE ELECTRO-STATIC ELEMENT.STATIC ELEMENT.STATIC ELEMENT.STATIC ELEMENT.STATIC ELEMENT.

No OutputNo OutputNo OutputNo OutputNo Output

Check that all your system components are turned on.

Check your speaker wires and connections.

Check all interconnecting cables.

Weak Output, Loss of HighsWeak Output, Loss of HighsWeak Output, Loss of HighsWeak Output, Loss of HighsWeak Output, Loss of Highs

Check the power cord. Is it properly connected to thespeaker?

Exaggerated Highs, Brightness.Exaggerated Highs, Brightness.Exaggerated Highs, Brightness.Exaggerated Highs, Brightness.Exaggerated Highs, Brightness.

Check the toe-in of the speakers. Read Room Place-Room Place-Room Place-Room Place-Room Place-mentmentmentmentment for more information.

Muddy BassMuddy BassMuddy BassMuddy BassMuddy Bass

Check placement. Try moving the speakers closer to thefront and side walls.

Check the type of feet being used. Try attaching thecoupling spikes.

Lack of BassLack of BassLack of BassLack of BassLack of Bass

Check your speaker wires. Is the polarity correct?


Recommended Music

Analog Discs:Analog Discs:Analog Discs:Analog Discs:Analog Discs:

Astounding Sound Show ........... Reference Recordings RR-7

Chet Atkins in Hollywood................................ RCA LSP-1993

Berlioz: Symphonie Fantastique .......... Chesky Records CR1

Big Band Jazz........................................ Umbrella UMB-DD4

The Chicago Symphony Winds ................. Sheffield Lab 22

Judy Collins: Judith....................................... Elektra 6E-111

Phil Collins: Face Value ..................................Virgin V-2185

Dafos ...................................... Reference Recordings RR-12

Miles Davis: You're Under Arrest ...........Columbia FC 40023

Arturo Delmoni:

Songs My Mother Taught Me ............ North Star DS0004

Dire Straits: Dire Straits ........................ Warner Bros. BSK 3266

Dire Straits: Love Over Gold .................. Warner Bros. 23728-1

Fresh Aire II .............................. American Gramophone 359

Fresh Aire III ............................. American Gramophone 365

Gershwin: An American in Paris .......... Chesky Records RC8

Earl Klugh: Crazy for You ............................ Liberty LT 51113

Mahler: Symphony No. 1 ............................ Telarc DG10066

Joni Mitchell: For the Roses ......................... Asylum SD 5057

Moroder: Cat People............................ Backstreet BSR-6107

The Moscow Sessions....................... Sheffield Lab TLP-1000

Ohio Players: Gold .............................. Mercury SRM-1-1122

Pink Floyd: Dark Side of the Moon ....... EMI Harvest SHVL-804

Rachmaninoff: Piano Concerto No. 2 . Chesky Records CR2

The Reiner Sound .......................................... RCA LSC-2183

Rickie Lee Jones: Rickie Lee Jones ..... Warner Bros. BSK 3296

Shalamar: The Look........................................Solar 9-60239

The Sheffield Track Record ........................ Sheffield Lab-20

Strauss: Til Eulenspiegel .......... Reference Recordings RR-16

Stanley Turrentine: Cherry .................. CTI Records CTI 6017

McCoy Tyner & Jackie McLean:

It's About Time ................................. Blue Note BT 85102

Dionne Warwick: Soulful ............................. Scepter SPS-573

Compact Discs:Compact Discs:Compact Discs:Compact Discs:Compact Discs:

Pachelbel Canon:

The Acadamy of Ancient Music, L'Oiseau-Lyre 410 553-2

Count Basie & His Orchestra: 88 Basie Street, Pablo 3112-42

David Benoit:

Every Step of the Way ...............GRP Records GRD-9558

This Side Up .................................... En Pointe ENP 0001

Cantate Domino ................................... Proprius PRCD 7762

Copland:

Appalachian Spring, Rodeo, Fanfare Telarc CD-80078

Country .............................. Windham Hill Records WD-1039

Dafos ................................ Reference Recordings RR-12 CD

Dire Straits: Brothers in Arms.............. Warner Bros. 9 25264-2

Dorian Sampler Vol. 1 ........................... Dorian DOR-90001

Freddie Hubbard: Ride Like the Wind .... En Pointe ENP 0002

Huey Lewis and the News: Sports ...........Chrysalis VK 41412

Bob James & Earl Klugh: One On One........... CBS CK 36241

Albert King: Live Wire................... Mobile Fidelity MFCD 838

Rob McConnell and the Boss Brass:

Present Perfect ...................................... MPS 823 543-2

Nojima Plays Liszt .............. Reference Recordings RR-25CD

Linda Ronstadt: Round Midnight .............Asylum 9 60489-2

Round-Up ................................................. Telarc CD-80141

Sainte-Saens: Symphony No. 3 ................ Philips 412 619-2

Diane Schuur and the Count Basie Orchestra,

GRP Records GRD-9550

Paul Simon: Graceland ................... Warner Bros. 9 25447-2

Ein Straussfest ........................................... Telarc CD-80098

Tchaikovsky: Piano Concerto No. 1..Chesky Records CD-13

Tchaikovsky: Violin Concerto ...........Chesky Records CD-12

Vollenweider: Caverna Magica ................... CBS MK 37827

Steve Winwood: Back in the High Life ........ Island 9 25548-2

Yellowjackets: Shades ................MCA Records MCAD-5752


Glossary

ACACACACAC. Abbreviation for alternatingcurrent.

Active crossoverActive crossoverActive crossoverActive crossoverActive crossover. Uses activedevices (transistors, IC’s,tubes) and some form of powersupply to operate.

AmplitudeAmplitudeAmplitudeAmplitudeAmplitude. The extreme range of asignal. Usually measured from theaverage to the extreme.

ArcArcArcArcArc. The visible sparks generated byan electrical discharge.

BassBassBassBassBass. The lowest frequencies ofsound.

Bi-AmplificationBi-AmplificationBi-AmplificationBi-AmplificationBi-Amplification. Uses an electroniccrossover or line-level passivecrossover and separate poweramplifiers for the high and lowfrequency loudspeaker drivers.

CapacitanceCapacitanceCapacitanceCapacitanceCapacitance. That property of acapacitor which determines howmuch charge can be stored in itfor a given potential differencebetween its terminals, measuredin farads, by the ratio of thecharge stored to the potentialdifference.

CapacitorCapacitorCapacitorCapacitorCapacitor. A device consisting oftwo or more conducting platesseparated from one another byan insulating material and usedfor storing an electrical charge.Sometimes called a condenser.

ClippingClippingClippingClippingClipping. Distortion of a signal by itsbeing chopped off. An overloadproblem caused by pushing anamplifier beyond its capabilities.The flat-topped signal has highlevels of harmonic distortionwhich creates heat in a loud-speaker and is the major causeof loudspeaker componentfailure.

CrossoverCrossoverCrossoverCrossoverCrossover. An electrical circuit thatdivides a full bandwidth signalinto the desired frequency bandsfor the loudspeaker components.

dB (decibel)dB (decibel)dB (decibel)dB (decibel)dB (decibel). A numerical expres-sion of the relative loudness of asound. The difference in decibelsbetween two sounds is ten timesthe common logarithm of the ratioof their power levels.

DCDCDCDCDC. Abbreviation for direct current.

DiffractionDiffractionDiffractionDiffractionDiffraction. The breaking up of asound wave caused by sometype of mechanical interferencesuch as a cabinet edge, grillframe, or other similar object.

DiaphragmDiaphragmDiaphragmDiaphragmDiaphragm. A thin flexible mem-brane or cone that vibrates inresponse to electrical signals toproduce sound waves.

DistortionDistortionDistortionDistortionDistortion. Usually referred to in terms oftotal harmonic distortion (THD)which is the percentage ofunwanted harmonics of the drivesignal present with the wantedsignal. Generally used to meanany unwanted change introducedby the device under question.

DriverDriverDriverDriverDriver. See transducer.

Dynamic RangeDynamic RangeDynamic RangeDynamic RangeDynamic Range. The rangebetween the quietest and theloudest sounds a device canhandle (often quoted in dB).

EfficiencyEfficiencyEfficiencyEfficiencyEfficiency. The acoustic powerdelivered for a given electricalinput. Often expressed asdecibels/watt/meter (dB/w/m).

ESLESLESLESLESL. Abbreviation for electrostaticloudspeaker.

HeadroomHeadroomHeadroomHeadroomHeadroom. The difference, indecibels, between the peak andRMS levels in program material.

HybridHybridHybridHybridHybrid. A product created by themarriage of two different tech-nologies. Meant here as thecombination of a dynamicwoofer with an electrostatictransducer.

Hz (Hertz)Hz (Hertz)Hz (Hertz)Hz (Hertz)Hz (Hertz). Unit of frequency equiva-lent to the number of cycles persecond.

ImagingImagingImagingImagingImaging. To make a representationor imitation of the original sonicevent.

ImpedanceImpedanceImpedanceImpedanceImpedance. The total oppositionoffered by an electric circuit tothe flow of an alternating currentof a single frequency. It is acombination of resistance andreactance and is measured inohms. Remember that a speaker’simpedance changes withfrequency, it is not a constantvalue.


InductanceInductanceInductanceInductanceInductance. The property of anelectric circuit by which a varyingcurrent in it produces a varyingmagnetic field that introducesvoltages in the same circuit or ina nearby circuit. It is measured inhenrys.

InductorInductorInductorInductorInductor. A device designedprimarily to introduce inductanceinto an electric circuit. Sometimescalled a choke or coil.

LinearityLinearityLinearityLinearityLinearity. The extent to which anysignal handling process isaccomplished without amplitudedistortion.

MidrangeMidrangeMidrangeMidrangeMidrange. The middle frequencieswhere the ear is the most sensi-tive.

Passive crossoverPassive crossoverPassive crossoverPassive crossoverPassive crossover. Uses no activecomponents (transistors, IC’s,tubes) and needs no powersupply (AC, DC, battery) tooperate. The crossover in atypical loudspeaker is of thepassive variety. Passive cross-overs consist of capacitors,inductors and resistors.

PhasePhasePhasePhasePhase. The amount by which onesine wave leads or lags a secondwave of the same frequency. Thedifference is described by theterm phase angle. Sine waves inphase reinforce each other; thoseout of phase cancel.

Pink noisePink noisePink noisePink noisePink noise. A random noise used inmeasurements, as it has the sameamount of energy in eachoctave.

PolarityPolarityPolarityPolarityPolarity. The condition of beingpositive or negative with respectto some reference point or object.

RMSRMSRMSRMSRMS. Abbreviation for root meansquare. The effective value of agiven waveform is its RMS value.Acoustic power is proportional tothe square of the RMS soundpressure.

ResistanceResistanceResistanceResistanceResistance. That property of aconductor by which it opposesthe flow of electric current,resulting in the generation of heatin the conducting material,usually expressed in ohms.

ResistorResistorResistorResistorResistor. A device used in a circuitprimarily to provide resistance.

ResonanceResonanceResonanceResonanceResonance. The effect producedwhen the natural vibrationfrequency of a body is greatlyamplified by reinforcing vibra-tions at the same or nearly thesame frequency from anotherbody.

SensitivitySensitivitySensitivitySensitivitySensitivity. Volume of sounddelivered for a given electricalinput.

StatorStatorStatorStatorStator. The fixed part forming thereference for the moving dia-phragm in a planar speaker.

THDTHDTHDTHDTHD. Abbreviation for total harmonicdistortion. (See Distortion.)

TIMTIMTIMTIMTIM. Abbreviation for transientintermodulation distortion. (SeeDistortion.)

TransducerTransducerTransducerTransducerTransducer. Any of various devicesthat transmit energy from onesystem to another, sometimes onethat converts the energy in form.Loudspeaker transducers convertelectrical energy into mechani-cal motion.

TransientTransientTransientTransientTransient. Applies to that which lastsor stays but a short time. Achange from one steady-statecondition to another.

TweeterTweeterTweeterTweeterTweeter. A small drive unit designedto produce only high frequencies.

WavelengthWavelengthWavelengthWavelengthWavelength. The distance mea-sured in the direction of progres-sion of a wave, from any givenpoint characterized by the samephase.

White noiseWhite noiseWhite noiseWhite noiseWhite noise. A random noise used inmeasurements, as it has the sameamount of energy at eachfrequency.

WooferWooferWooferWooferWoofer. A drive unit operating in thebass frequencies only. Drive unitsin two-way systems are not truewoofers but are more accuratelydescribed as being mid/bassdrivers.


The Sequel II hybrid speaker systemconsists of a broad-range singleelement electrostatic transducerintegrated with a quick-responsewoofer. This approach takes advan-tage of the benefits that both tech-nologies have to offer.

Dispersion is a controlled 30 degrees.This was achieved by curving theelectrostatic transducer element itself,an elegantly simple solution.

System Frequency ResponseSystem Frequency ResponseSystem Frequency ResponseSystem Frequency ResponseSystem Frequency Response28-24,000 Hz ± 2dB

Electrostatic Frequency Re-Electrostatic Frequency Re-Electrostatic Frequency Re-Electrostatic Frequency Re-Electrostatic Frequency Re-sponsesponsesponsesponsesponse100-24,000 Hz ± 2dB

Woofer Frequency ResponseWoofer Frequency ResponseWoofer Frequency ResponseWoofer Frequency ResponseWoofer Frequency Response28-2,000 Hz ± 2dB

Woofer SpeedWoofer SpeedWoofer SpeedWoofer SpeedWoofer Speed@ 50 Hz: 6.3ms (capable of 160 Hz)@ 100 Hz: 1.2ms (capable of 830 Hz)

Bass Control SwitchBass Control SwitchBass Control SwitchBass Control SwitchBass Control Switch+2dB from 40 - 160 Hz

Crossover FrequencyCrossover FrequencyCrossover FrequencyCrossover FrequencyCrossover Frequency250 Hz at 12dB per octave

Dispers ionDispers ionDispers ionDispers ionDispers ionHorizontal: 30 DegreesVertical: 4' Line Source

Sensi t iv i tySensi t iv i tySensi t iv i tySensi t iv i tySensi t iv i ty89dB/2.83 volts/meter

Power HandlingPower HandlingPower HandlingPower HandlingPower Handling200 watts per channel

Recommended Amplifier PowerRecommended Amplifier PowerRecommended Amplifier PowerRecommended Amplifier PowerRecommended Amplifier Power80 - 200 watts per channel

ImpedanceImpedanceImpedanceImpedanceImpedanceNominal: 6 ohms; Minimum: 2 ohms

Phase AnglePhase AnglePhase AnglePhase AnglePhase AngleLess than 45o

WeightWeightWeightWeightWeight110 lbs/each

S i zeS i zeS i zeS i zeS i ze72"H x 14"W x 13"D

ComponentsComponentsComponentsComponentsComponentsCustom-wound audio transformerspolypropylene bypass caps,100% OFC coils.

Sequel II Specifications


Notes

$ 3.00$ 3.00$ 3.00$ 3.00$ 3.00

2001 delaware streetp.o. box 707

lawrence, kansas 66044ph: 913.749.0133

© 1989 martin-logan ltd.martin-logan ltd.martin-logan ltd.martin-logan ltd.martin-logan ltd. all rights reserved

T H E E L E C T R O S T A T I C T E C H N O L O G Y

Documents

MartinLogan Sequel II User's Manual · The Electrostatic Concept 5 History 6 Martin-Logan Exclusives 8 Operation 10 Room Acoustics 14 Placement 18 Questions 21 Troubleshooting 22