CT8XO MK2 Installation and Setup Manual - Bowers … · CT8 DS - Installation Into Drywall ... CT8 DS surround speaker, which needs to protrude into the room in order for the side-firing

CT800 Series

CT8XO MK2Installation and Setup Manual

1

Table of Contents

Warranty .............................................................................................. 2

Important Safety Instructions .......................................................... 3

Environmental Information ............................................................... 4

Introduction ......................................................................................... 4

Planning the Installation ................................................................... 7 Speaker Position ................................................................................ 7

Surround Speaker Dispersion Mode ............................................... 8

Mounting the Speakers ..................................................................... 9 CT8 DS - Installation Into Drywall ......................................................11

CD8 DS - Installation to Wall Surface ................................................12

Connecting the System ....................................................................14 CT8 XO Mk2 Wiring Diagram ............................................................15

The CT8 OX Mk2 Crossover/Equaliser ...........................................15 Description of Controls .....................................................................16

Equipment Required .........................................................................17

ConfiguringtheCT8XOtothespeaker .............................................17

ConfiguringtheUnittotheGainofEachPowerAmplifier .................17

ConfiguringtheEqualisers ................................................................18

Running In and Ancillary Equipment ............................................. 22

Aftercare ............................................................................................ 22

Technical Specifications ................................................................. 23

1

2

Warranty

Dear customer,

Welcome to B&W.

Thisproducthasbeendesignedandmanufacturedtothehighestquality

standards.However,ifsomethingdoesgowrongwiththisproduct,B&W

Group Ltd and its national distributors warrant free of charge labour

(exclusionmayapply)andreplacementpartsinanycountryservedbyan

officialB&Wdistributor.

Limited Warranty

This limitedwarranty is valid foraperiodof fiveyears from thedateof

purchaseortwoyearsforelectronicsincludingamplifiedloudspeakers.

Terms and Conditions

1 Thewarrantyislimitedtotherepairoftheequipment.Neither

transportation,noranyothercosts,noranyriskforremoval,

transportationandinstallationofproductsiscoveredbythis

warranty.

2 Thiswarrantyisonlyvalidfortheoriginalowner.Itisnot

transferable.

3 Thiswarrantywillnotbeapplicableincasesotherthandefectsin

materialsand/orworkmanshipatthetimeofpurchaseandwillnot

beapplicable:

a)fordamagescausedbyincorrectinstallation,connectionor

packing,

b)fordamagescausedbyanyuseotherthancorrectuse

describedintheusermanual,negligence,modifications,oruseof

partsthatarenotmadeorauthorisedbyB&W,

c)fordamagescausedbyfaultyorunsuitableancillaryequipment,

d)fordamagescausedbyaccidents,lightning,water,fireheat,

war,publicdisturbancesoranyothercausebeyondthereasonable

controlofB&Wanditsappointeddistributors,

e)forproductswhoseserialnumberhasbeenaltered,deleted,

removedormadeillegible,

f)ifrepairsormodificationshavebeenexecutedbyan

unauthorisedperson.

4 Thisguaranteecomplementsanynational/regionallawobligations

ofdealersornationaldistributorsanddoesnotaffectyour

statutoryrightsasacustomer.

How to claim repairs under warranty

Shouldserviceberequired,pleasefollowthefollowingprocedure:

1 Iftheequipmentisbeingusedinthecountryofpurchase,you

shouldcontacttheB&Wauthoriseddealerfromwhomthe

equipmentwaspurchased.

2 Iftheequipmentisbeingusedoutsidethecountryofpurchase,

youshouldcontactB&Wnationaldistributorinthecountryof

residencewhowilladvisewheretheequipmentcanbeserviced.

YoucancallB&WintheUKorvisitourwebsitetogetthecontact

detailsofyourlocaldistributor.

Tovalidateyourwarranty,youwillneedtoproducethewarrantybooklet,

completed and stamped by your dealer on the date of purchase.

Alternatively, you will need the original sales invoice or other proof of

ownershipanddateofpurchase.

2

3

Important Safety Instructions

WARNINGS:

1 Readtheseinstructions.

2 Keeptheseinstructions.

3 Heed all warnings.

4 Follow all instructions.

5 Donotusethisapparatusnearwater.

6 Cleanonlywithdrycloth.

7 Donotblockanyventilationopenings.Installinaccordancewiththe

manufacturer’s instructions.

8 Donotinstallnearanyheatsourcessuchasradiators,heatregisters,

stoves,orotherapparatus(includingamplifiers)thatproduceheat.

9 Donotdefeatthesafetypurposeofthepolarizedorgrounding-type

plug.Apolarizedplughastwobladeswithonewiderthantheother.

Agroundingtypeplughastwobladesandathirdgroundingprong.

Thewidebladeorthethirdprongareprovidedforyoursafety.If

theprovidedplugdoesnotfitintoyouroutlet,consultanelectrician

forreplacementoftheobsoleteoutlet.

10 Protectthepowercordfrombeingwalkedonorpinchedparticularly

atplugs,conveniencereceptaclesandthepointwheretheyexitfrom

theapparatus.

11 Onlyuseattachments/accessoriesspecifiedbythemanufacturer.

12 Useonlywiththecart,stand,tripod,bracket,ortable

specifiedbythemanufacturer,orsoldwiththeapparatus.

Whenacartisused,usecautionwhenmovingthe

cart/apparatuscombinationtoavoidinjuryfromtip-over.

13 Unplugthisapparatusduringlightningstormsorwhenunusedfor

long periods of time.

14 Referallservicingtoqualifiedservicepersonnel.Servicingisrequired

whentheapparatushasbeendamagedinanyway,suchaspower-

supplycordorplugisdamaged,liquidhasbeenspilledorobjects

havefallenintotheapparatus,theapparatushasbeenexposedto

rainormoisture,doesnotoperatenormally,orhasbeendropped.

15 Donotexposethisapparatustodrippingorsplashingandensure

thatnoobjectsfilledwithliquids,suchasvases,areplacedonthe

apparatus.

16 TocompletelydisconnectthisapparatusfromtheACMains,

disconnectthepowersupplycordplugfromtheACreceptacle.

17 Themainsplugofthepowersupplycordshallremainreadily

operable.

18 Whenreplacementpartsarerequired,besuretheservicetechnician

hasusedreplacementpartsspecifiedbythemanufacturerorhave

thesamecharacteristicsastheoriginalpart.Unauthorised

substitutionsmayresultinfire,electricshockorotherhazards.

19 Forcontinuedprotectionagainstfirehazard,usefusesonlyofthe

correct type and rating.

20 Thisproductshouldbeoperatedonlyfromthetypeofpowersource

indicatedbythemarkingadjacenttothepowercordentry.Ifyouare

notsureofthetypeofpowersupplytoyourhome,consultyour

product dealer or local power company.

21 Do not overload wall outlets, extension cords or integral convenience

receptacles,asthiscanresultinariskoffireorelectricshock.

22 Neverpushobjectsofanykindintothisproductthroughopenings,

astheymaytouchdangerousvoltagepointsorshortoutpartsthat

couldresultinafireorelectricshock.Neverspillliquidofanykind

ontheproduct.Donotplaceanyobjectcontainingliquidontopof

theproduct.

Caution:Toreducetheriskofelectricshock,donotdismantletheapparatusand

donotexposetheapparatustorainormoisture.Nouser-serviceableparts

inside.Referservicingtoqualifiedpersonnel.

Explanation of Graphical Symbols

Thelightningflashwithinanequilateraltriangle is intendedto

alertyouto thepresenceofuninsulated“dangerousvoltage”

within the product’s enclosure that may be of sufficient

magnitudetoconstituteanelectricshocktopersons.

The exclamation point within an equilateral triangle is

intended toalert you to thepresenceof importantoperating

and maintenance (servicing) instructions in the literature

accompanyingtheappliance.

3

4

Introduction

ThankyouforpurchasingaBowersandWilkinsCustomTheatresystem.

Sinceitsfoundationin1966,thecontinuingphilosophyofB&Whasbeen

the quest for perfect sound reproduction. Inspired by the company’s

founder, the late John Bowers, this quest has entailed not only high

investment in audio technology and innovation but also an abiding

appreciationofmusicandmoviestoensurethatthetechnologyisputto

maximum effect.

CustomTheatre speakers are specifically designed tobebuilt into the

fabric of the listening room or into custom furniture as part of a fully

designedtheatreconcept.Tothatend,theyincorporateseveralfeatures

thatenablethemtobeadaptedtoawiderangeofinstallationconditions

and deliver superb sound quality. However, they specifically do not

incorporate features found on some other B&W products that are not

appropriatetothistypeofinstallation.Anexampleofsuchafeaturewould

betweeterontop,whichonlyoperateswellwithafree-standingspeaker.

Furthermore,becauseofthenormalcustominstallpracticeofhidingbuilt-

inspeakerswithacousticallytransparentcloththatmatchesthedécor,all

themodelsexceptonearesuppliedwithoutgrilles.Theexceptionisthe

CT8DSsurroundspeaker,whichneedstoprotrudeintotheroominorder

fortheside-firingdriverstooperateproperly.

Nomatterhowgoodthespeakersthemselvesmaybe,theywillnotdeliver

their full potential unless properly installed. Please read through this

manualfully.Itwillhelpyouoptimisetheperformanceofthesystem.

B&Wdistributestoover60countriesworldwideandmaintainsanetwork

ofdedicateddistributorswhowill beable tohelpshould youhaveany

problemsyourdealercannotresolve.

AllB&Wproductsaredesignedtocomplywithinternationaldirectiveson

the Restriction of Hazardous Substances (RoHS) in electrical and

electronicequipmentandthedisposalofWasteElectricalandElectronic

Equipment (WEEE).

These symbols indicate compliance and that the products must be

appropriatelyrecycledorprocessedinaccordancewiththesedirectives.

Consultyourlocalwastedisposalauthorityforguidance.

4

Environmental Information

5

A3-wayspeakerintendedforfrontleftandrightchannels,

one placed in vertical orientation at each side of the

screen.

Afullrangesurroundspeakerthatmayoperateineither

2-way dipole or 3-way monopole mode.

A 3-way centre channel speaker that is acoustically

similar to the CT8 LR, but designed with a more

symmetricaldriveunit layoutso that itmaybeused in

horizontal orientation immediately above or below the

screen.

Asubwooferthatmaybeaddedtoanyoralltheabove

threemodelstoextendtheirbassresponsewellbelow

theacceptedlowerlimitonhumanhearing.

Anactive,line-levelcrossover/equaliserthat:

a) isrequiredforeachCT8LR,CT8CCandCT8DS

andmustbeconfiguredtotheparticularspeaker

type.

b) providesactivefilteringbetweenmidrangeand

bassdriversandbetweenbassdriversand

CT8 SW (if used).

c) controlswhetherasurround speaker operates in

dipole or monopole mode and, in dipole mode,

controlsthedirectionofthepositiveandnegative

polaritylobes.

d) provides high- and low-frequency level control,

plusthreeadjustableparametricequalisersto

adjustforspeaker/roominterferanceeffects.

5

CT8 LR

CT8 DS

CT8 CC

CT8 SW

CT8 XO Mk2

6

Althoughthespeakersaresemi-activeandrequireanactivecrossover,all

poweramplificationmustbeseparatelysourced.EachCT8LR,CT8CC

andCT8DSrequirestwochannelsofpoweramplification,orthreeifused

with a CT8 SW subwoofer. This allows the usermaximum flexibility in

choosingthesecomponents.

The CT8 SW subwoofer, unlike the majority of subwoofers currently

available, does not contain its own power amplifier and is used in a

different manner than is usual. The original concept of home theatre

basedonvariousDolbyDigitalandDTSsystemsadvocatesfiveormore

mainchannelsplusasingleLowFrequencyEffects (LFE)channel.The

mainchannelscontain full rangesignalsand theLFEchannelcontains

specialeffectsuptoapproximately140Hz.Recognisingthatmanypeople

donotwantfiveormorefull-rangespeakers inoneroom,DolbyDigital

and DTS systems allow for the main channels to operate with small

speakershavingarestrictedbassextension.Thelowestfrequenciesfrom

these channels are filtered off and added to the LFE channel to be

reproducedbyasubwoofer.Thefiltercut-offfrequencyisnormallysetat

around 80Hz, the rationale being that sound gets progressively less

directional the lower the frequency and localisation becomes less

important.Thisistruetosomeextent,buttheearscanprocessdirectional

informationatvery low frequenciesand themore thebassof themain

channelsisextended,themorerealisticthesoundstagebecomes.Many

high-end processors offer lower filter cut-off frequencies for this very

reason.

Topreservethisdirectionalinformation,aCT8SWmaybeaddedtoeach

ofthemainchannelsasdesired,extendingthefrequencyresponsewell

below20Hz.Theminimumrecommendedconfigurationistoassignone

subwoofer to each of the front left and right channels, restoring some

directional information to the action directly on the screen and full

directional information to 2-channel audio programme. The sense of

spatialacousticimprovesasmoresubwoofersareaddedtotheremaining

channels. If higher sound levels are required for larger listening

environmentsandgreaterrealism,uptotwosubwoofersmaybeaddedto

eachmain channel. (It should be noted here that the addition ofmore

subwooferstoanysinglechannelrequiresanadjustmentofthesubwoofer

outputlevelofthatchannel’sCT8XOinordertorestorethecorrecttonal

balance.)TheLFEchannelisthendistributedtoallthemainchannelsthat

have a subwoofer assigned by the simple action of configuring the

surroundprocessorasiftherewerenosubwooferpresentandspecifying

wheretheLFEsignalshouldberouted.Strictlyspeaking,thephrase“no

subwoofer”heremeans“nosubwooferdedicatedtotheLFEchannel”.

Safety Warning!ACT800systemiscapableofproducingveryhighsound

pressurelevels.Prolongedexposuretohighsoundlevels

canleadfirsttotemporaryandlaterpermanenthearing

damage.DonotexceedrecommendedLeq(equivalent

soundlevel)exposurelevels,forexample,thosespecified

inISO1999:1990.

6

7

Planning the Installation

Check the contents against Figure 1

Planning the Installation

Becauseofthebuilt-innatureoftheinstallation,theplanningstageisof

theutmostimportance.Anyneedtoadjustspeakerposition,forexample,

isamuchmoreinvolvedprocessthanwithfree-standingspeakers.Care

mustalsobetakentoconstructpropersupportforthespeakers.Itisall

tooeasytoinducethepanelsofcustomfurnituretovibrateandcolourthe

sound unless precautions are taken to prevent it.

Speaker Position

Figures2to4showtherecommendedlocationsinplanviewforthemain

speakers in5.1,6.1and7.1channel installations.Somedimensionsare

marked~,indicatingthatthereissomelatitudeallowedeachsideofthe

figure, and some have a recommended range for optimum results.

Subwoofersshouldbeplacedclosetothemainspeakerstowhichthey

are assigned.

For successful operation of the surround speaker, CT8 DS, in dipole

mode, it is important thatall listenerssitwithinthespeaker’snullzone.

Thisisthe60°widezoneoflowdirectsoundlevelcreatedbytheopposing

polaritydriversoneachside.Youwillnoticefromfigures3and4thatfor

6.1and7.1systems,thesidespeakersareshowninlinewiththecentreof

thelisteningarea.Thisissuitableregardlessofwhetherthesespeakers

areusedindipoleormonopolemode.However,for5.1systems,thetwo

surroundspeakersshouldbeplacedsomewhatbehindthelistenersfor

effective results in monopole mode, or if you wish to switch between

monopole and dipole modes for different types of programme. If you only

everintendtousethemindipolemode,thetwosurroundspeakersshould

revert to the in-line position. Please read the discussion on surround

modesinthenextsectionforaclearerunderstandingofthebenefitsof

eachtype.

Forlargeraudiencesizes,amoreevencoverageofthesurroundsound

fieldmaybeobtained if the surroundspeakersareelevatedaboveear

height, as in a commercial cinema. In that case, the speakersmaybe

raised so that themidrange/tweeter array is approximately 60cm (2 ft)

aboveseatedearheight.

ForcorrectoperationoftheCT8DSindipolemode,itisimportantnotto

obstructthesidefiringdrivers.Thespeakershouldbemountedwithat

leastthefrontportioncontainingtheside-firingdriversprotrudingintothe

roomandanycustomisedcoveringshouldbeacousticallytransparent.

7

Figure 1

Figure font: Helv 45, 7ptFigure spacing: 7 x 7 mm

Figure 2 Figure 3

Figure 4

Figure 5

~40o

~120o

~60o

Figure 7

Figure 6Figure 1


Figure 2 Figure 3

Figure 4

Figure 5

~40o

~120o

~60o

Figure 7

Figure 6

Figure 1


Figure 2 Figure 3

Figure 4

Figure 5

~40o

~120o

~60o

Figure 7

Figure 6Figure 1


Figure 2 Figure 3

Figure 4

Figure 5

~40o

~120o

~60o

Figure 7

Figure 6

8

Surround Speaker Dispersion Mode

Surround speakers generally fall into twomain types – those that one

mightdescribeas ‘normal’speakers-so-calledmonopoles,wherethe

sound comes from a set of drive units mounted on the front of the

enclosure-andthosethatgiveamorediffusesoundfield,suchasdipoles.

Eachtypehasitsadvantages.

Mostmulti-channelmusicisrecordedwithhomeentertainment inmind

andismonitoredusingmonopolesurroundspeakers,whateverthemulti-

channel recording format.Thisenablesbetter locationofsideand rear

images,althoughtheformationofsuchimagesisneverquiteasprecise

asitisbetweenthefrontspeakers.

Mostfilmsareoriginallybalancedforcinemas,wherealargenumberof

speakersspreadaroundtheauditoriumareusedtocreatethesurround

soundfield.Inthatcasetherearemoresurroundspeakersthanthereare

discretechannelsofinformationandalesspreciseimageiscreatedthat

gives an all-enveloping effect. Dipoles and similar diffuse speakers are

betteratrecreatingthistypeofsoundfieldinthehome,butusingfewer

speakerstodoit.Imagepositioningwiththesetypesofspeakerisnever

as precise as it can be with monopoles. However, they do have the

advantageofmakingiteasiertobalancethesystemforalargerlistening

area.

Youmaywellreceiveconflictingadvicefromdifferentsourcesonthebest

typeofsurroundspeakertouse.Thetruthisthatthereisnooneperfect

solutionforallsituationsandthefinalchoiceforanygivenapplicationwill

beinfluencedbypersonalpreference.

TheCT8DSisaspecialistsurroundspeakerandhastheadvantageof

offeringachoiceofbothmonopoleanddipoleoperation.Themodeof

operation is set by a relay inside the speaker, the state of which is

controlledfromtheCT8XOcrossover/equaliserassignedtothespeaker

via a cable connecting the 3.5mm sockets on both products. If this cable is not fitted, the speaker will only operate in monopole mode. On the CT8 XO is a switch used to select the mode. In the

monopoleposition,thisswitchmaybeoverriddenbya12Vtriggersignal

fromthesurroundprocessor.Somesurroundprocessorscanrecognise

thetypeofprogrammebeingplayedfromacodeonthediscandallow

youtoassigna12Vtriggertothiscode.Someotherprocessorsallowyou

toassigna12Vtriggertotheinputselectionandyoumay,forexample,

use a different disc player for audio and movies and set the trigger

accordingly. In both these cases, you may choose whichever type of

operation best suits the conditions of the listening room, the size of

audienceandthetypeofprogrammebeingplayed.Indeed,youmayeven

change thecharacteristic fordifferent typesofprogrammeand,as the

totalenergyintotheroomisthesameinbothmodes,norecalibrationof

theinstallationisnecessarywhenswitchingbetweenthem.

The twobassdriversoperate inbothmodes. Inmonopolemode, they

crossovertothemidrangeandtweeterdriveunitsonthefrontfaceand

thespeakerisacousticallysimilartotheCT8LR,butwithouttheswivelling

head. Indipolemode, thebassdriverscrossover to thesix side-firing

drivers.Thedriveunitsonopposingsidesareconnectedoutofphase

withoneanother,whichcreatesawedge-shapednullzone,approximately

60owide,atrightanglestothewall.Ifthelistenerssitwithinthiszone,they

becomelessawareofthelocationofthespeakersandhearmorereflected

sound;hencethediffusenatureofthesoundfield.(figure5)

8

Figure 1


Figure 2 Figure 3

Figure 4

Figure 5

~40o

~120o

~60o

Figure 7

Figure 6

9

Foroptimumperformance,itisimportantthatthespeakersarefirmlyand

securelymounted.Allthespeakersmaybemounteddirectlyatfloorlevel,

but,asmentionedabove,itcanbebeneficialtoraisethepositionofthe

surroundspeakersand,ifthescreenishigh,itmayalsobebeneficialto

dothesamewiththefrontspeakers.Inthatcase,thesupportingstructure

forthespeakersshouldbesubstantial.Ifconstructedofwoodenstudding,

theframeworkshouldbearrangedtobedirectlybeneaththefeetofthe

speaker.(figure6)

Allthespeakersareequippedwithrollerglidesonthebasepanel.These

allowthespeakerstobeeasilypushedintoplaceincustomfurniture.In

ordertopositionthespeakersaccurately,wesuggestyoucreatecircular

recesses 15mm (5/8 in) diameter in the support surface to locate the

glides.

Toavoidrockingwhenthespeakersareinposition,itis

importantthattheserecessesareaccuratelypositioned

and a foot-positioning template is supplied for this

purpose.

Theshadedareaatthefrontofthetemplateistoallowclearanceforthe

movementofthebasscones.FortheCT8DS,theside-firingdriveunits

require free acoustic access into the listening room, indicated by the

shadedareaofthetemplateextendingroundthesides.TheCT8DSwill

normallyhavethefronthalfofthecabinetprotrudingclearintotheroom.

Itmay,however,bebuiltintoafalsepillar,butthismustbeacoustically

transparentatthesides,aswellasthefront,asindicatedbytheshaded

area.

Ifthespeakersaretobeinsetinafalsewall,afronttemplateisprovided

forguidanceincuttingtheaperture.Thetemplateisthesamesizeasthe

speaker,soremembertoleavesomeclearance.Theheightofthetemplate

includestherollerglides.

If thespeakersare tobemounted incustomfurniture,youshouldalso

ensurethat it issubstantiallybuiltandnotpronetoinducedvibration.It

should be braced where necessary and it may be beneficial to glue

bituminous damping pads, similar to those used in motor vehicles, to

largeunsupportedpanels.Suchpadsneedtobethickeronwoodthan

metalandaminimumof6mm(1⁄4in)shouldbeused.

Ifitisdesiredtoremovetherollerglides,usetheTorx®keysuppliedwith

thespeakertoremovetheretainingscrews.

An optional, spike foot kit is also available (Part No FP22359). The kit

contains4heavy-dutyfeetthathave40mm(1.6in)ofverticaladjustment,

allowing tilt up to 8oifdesired.Thistiltisinadditiontothatofferedbythe

adjustableheadunitoftheCT8LRandCT8CC.

Thefeetarereversible,havingaspikeforcarpetsononeendandarubber

padforvulnerablesurfacesontheother.Fittingismosteasilyaccomplished

during unpacking, when the underside of the speaker is exposed.

(figure7)

9

Mounting the Speakers

Figure 1


Figure 2 Figure 3

Figure 4

Figure 5

~40o

~120o

~60o

Figure 7

Figure 6

Figure 1


Figure 2 Figure 3

Figure 4

Figure 5

~40o

~120o

~60o

Figure 7

Figure 6

Notethatiftheoptionalfeetarefitted,orifthespeakeris

tilted,appropriateallowanceoverandabovethatallowed

forinthetemplatemustbemadewhencuttinganaperture

inthewall.

Thethreadedbossesthatholdthefeethavealargeconicalshapeonone

side of the flange. Formaximum height, fit the bosseswith the conical

shapetowardsthefloor.(figure8)Forminimumheight,havethempointing

intothespeaker.(figure9)

Screwinthefeetclosetowhereyouthinkthefinaladjustmentwillbe,with

thespikesortherubberendsoutermostasappropriatetothefloorsurface.

Ifyoudonotintendtotiltthespeakers,orientthebosseswiththecones

inwardsandleavejustenoughthreadexposedtofitthelockingrings.Fit,

butdonottightenthelockingrings.

Standthespeakeruprightandadjustthefeetusingthemetalbarprovided

togivetheamountoftiltrequiredandtotakeupanyrocking.(figure10)

Finally,tightenthelockingringagainsttheboss,againusingthemetalbar.

(figure11)

The tweeterdriveunitsare fittedwithaprotectiveclearplasticcoveron

delivery.Thisistoavoidthedangerofdamagingthedomewheninstalling

thespeakers.Onceinstalled,theprotectioncovershouldberemovedby

simplypullingitawayfromthespeaker.

10

Figure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15

Figure 16a Figure 16b

Figure 17

Figure 14

CT8 XO

Figure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15


Figure 17

Figure 14

CT8 XOFigure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15


Figure 17

Figure 14

CT8 XO

Figure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15


Figure 17

Figure 14

CT8 XO

CT8 DS Only

Usingthefrontaspecttemplateprovided,markroundtheoutlineatthe

desiredpositionofthespeaker.Allowalittleforclearance.

If mounting the speaker at floor level, allow extra height if there is a

horizontalstudatfloorlevel.

Cutouttheapertureforthespeaker

Using the front aspect template provided, mark the centre line of the

retainingbracketon the insidesurfacesof the twoverticalstudseither

sideofthespeakerposition.

Screwthetwoanglebrackets(A)totheinsidefaceoftheverticalstruts.

Attachthewallbracket(C)totheanglebrackets(A)usingmachinescrews

(D)andtrappingthestudplate(B)inposition.

Patchthedrywallasnecessary.

Installation into drywall only. (figure 12)

Sothatitcanbesunkintoastandarddrywalluptotheleveloftheside-

firingdrivers,theCT8DShasarelativelyshallowcabinetforitsheightand

is front heavy. Tomaintain stability, it is equipped with a bracket that

enablestherearofthecabinettobeanchoredeithertoawallsurfaceor

theinternalstuddingofadrywall.

Inexistingconstruction:

Use a stud finding tool to locate the position of the vertical studs and

ensurethatthespeakerispositionedbetweenthem.

Ifthespeakeristobemountedabovefloorlevel,cutintothedrywallpanel

to expose the stud frame sufficiently to allow the insertion of a cross-

braceattheappropriateheighttosupportthespeaker.

Safety Warning!Ensurethecross-braceislevelandfittedstronglyenough

to take the substantial weight of the speaker. The

speakercanbesupportedby thecross-braceand the

retaining bracket alone if desired, or a more complex

support structuremay be constructed, for example to

hidetheundersideofthecabinet.

11

Figure 13

Figure 12

CT8 DS Only

Installation to wall surface only. (figure 13)

Using the front aspect template provided, mark the centre line of the

retainingbracketonthewall.

Thetwoanglebrackets(figure12-A)fromthekitarenotrequired.

Offerthewallbracket(C)tothewallandmarkthescrewpositionsateach

end.

Drillandplugthewalltotakescrewsintherange5mm-6mm(No.10to

No.12)

Screwthewallbrackettothewall,trappingthestudplate(B)inposition.

12

Figure 13

Figure 12

CT8 DS Only

...continue for all cases

Connectthesignalandtriggercablestothespeakers.

Usingtheallenkeyprovided,removethealuminiumfacingplateonthe

frontofthespeaker,takingcarethatthetweeterprotectioncoverremains

in position.

Fittheguidetubes(F)intothetwothroughholes.

Offer thespeaker intoposition,ensuringthattheguidetubes(F) locate

overthestudsofthebracket(B).

When the speaker is fully in position hard against the wall bracket,

withdrawtheguidetubes.

Using a 1/4 inch socket drive with extension and the 13mm socket

provided,fitthetwoflangednuts(E)ontothethreadedstudsandtighten.

Ifthesocketdrivedoesnothaveanutretainingfeature,werecommend

theuseofasmallpieceofBostik® Blu-Tack®orsimilarreusableadhesive

topreventthenutfallingoutofthedriveduringthisoperation.

Replace the facing plate on the front of the speaker and remove the

tweeter protection cover.

Ifthespeakerismountedonthefloorandrecessedintoadrywallhaving

ahorizontalstudmemberonthefloorsurface,theheightdifferencemay

betakenupbyfittingtheoptionalspikefeetinplaceofthetwofrontroller

glides(figure14).OnlyoneSpikefootkitwillberequiredforeachpairof

CT8 DS.

13

Figure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15


Figure 17

Figure 14

CT8 XO

Connecting the System

The Speakers

Allthespeakersareprovidedwithacomprehensivechoiceofconnection

methods. Binding posts accommodate 6mm (1/4 in) or 8mm (5/16 in)

spades,4mmbananaplugsandbarewireendsandaNeutrik® Speakon®

socket provides a professional industry standard multiway connection

thatmakesiteasytomakeaconnectioninconfinedspaces,especially

whenitissometimesdifficulttoseewhatyouaredoing.

ForallmodelsexceptthesubwooferCT8SW,therearetwoinputchannels,

one for bass and one formidrange/tweeter, requiring two channels of

poweramplification.Inallcases,ensurethatthepositiveterminalofthe

speakerisconnectedtothecorrespondingpositiveoutputconnectorof

the power amplifier. Failure to observe thiswill result in impaired tonal

balanceandimaging.Figure15showsatypicalconnectionmethodusing

bindingpostsandfigure16(a&b)thewiringconventionfortheNeutrik®

Speakon® plug.

CT8 DS OnlyInadditiontotheaudiosignalconnections,theCT8DSterminalpanel

hasa3.5mmstereojacksocket(figure17)toinputtwo12VtriggersignalsfromitsCT8XOunit.Useastereocoaxialcableterminatedateachendbya3.5mmstereojackplugtoconnecttothecomplementary

outputsocket(TRIGGEROUT)attherearoftheCT8XO.

14

Figure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15


Figure 17

Figure 14

CT8 XO

Figure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15


Figure 17

Figure 14

CT8 XO

Figure 8


Figure 9

Figure 10 Figure 11

SUB +

SUB -

SUB +

SUB -

Figure 15


Figure 17

Figure 14

CT8 XO

TheCT8XOisdesignedfor19-inrackmounting.Ifhousedinanenclosed

structure,properventilationmustbesuppliedasstatedintheinthesafety

instructions.

TheCT8XOisconnectedbetweenthesurroundprocessorandthepower

amplifiers. TheCT8XO signal input andoutput connections aremade

throughbalancedXLRconnectors.

ThewiringconventionforXLRconnectorsis:

Pin1:Ground

Pin2:Live(+)

Pin3:Return(-)

If12Vtriggerswitchingofthedispersionmode(monopole/dipole)ofthe

CT8DSsurroundspeakersisrequired,theassigned12Vtriggeroutput

fromthesurroundprocessorisconnectedtothe12VTRIGGERIN of one

oftheCT8XOunitsassignedtoaCT8DS.TheotherCT8XOtrigger

inputsareconnecteddaisychainfashionfromtheTRIGGERLOOP

socketofonetotheTRIGGERINofthenext.TheTRIGGEROUT sockets

areconnectedtotherelevantCT8DSspeakers.TheTRIGGERINand

TRIGGERLOOPsocketsaremono3.5mmjackswiththepositive(12V)wireconnectedtothetipoftheplug,whereastheTRIGGEROUTsocket

is a stereo3.5mmjackonboththeCT8XOandCT8DSloudspeaker.

Figure18showsthewiringdiagramofatypical5.1CT800systemhaving

twoCT8SWspeakers,oneassignedtoeachofthefrontleftandright

channels.

15

The CT8 XO Mk2 Crossover/Equaliser

Figure 18

To MF/HF of left CT8 LR

To LF of left CT8 LR

To left CT8 SW

To MF/HF of right CT8 LR

To LF of right CT8 LR

To right CT8 SW

Front left Front right

To MF/HF of left CT8 DS

To LF of left CT8 DS

Rear left

To MF/HF of right CT8 DS

To LF of right CT8 DS

Rear right

To MF/HF of CT8 CC

To LF of CT8 CC

Centre channel

To trigger of left CT8 DS To trigger of right CT8 DS

Processor

CT8 XO MK2 Rear Panel

Description of Controls

Theunitfeaturesacomprehensivesetofcontroldtotunetheperformance

ofeachspeakeraccordingtotheconditionsofuse.Theresponsemaybe

shapedbyacombinationofthreeparametricequalisers,eachhavinga

switchablerangeof+3dB,-3dBand-6dB,andlow-andhigh-frequency

contourcontrols,theeffectsofwhichareillustratedinfigure19.Selection

ofthesubwooferlow-passfilterfrequencyalsoprovidessomeresponse

adjustment.Inaddition,levelcontrolsareprovidedtocompensateforany

differencesingainbetweenboththesubwooferandLFpoweramplifiers

comparedtotheMF/HFpoweramplifier.

To access the front of the unit, remove the decorative face plate by

removingthePhilipsscrewsateitherend.

Refertofigure20forthelayoutoftheinputsandcontrols,whichhavethe

followingfunctions:

S1 Inputswitch Toswitchbetweentestandnormal

inputs.

T1 Test input socket To connect external signal generator.

S2 Speakerselectswitch Toswitchbetweenfront,centreand

surroundchannels.

S3 Dipoleselectswitch Toselectappropriatepositivelobe

orientationforleftandrightsurround

channelsindipolemode.

C1 High-frequencycontour SelectsHFeqoptions.±4dB.See

control figure19,bottomgraph.

C2 Low-frequencycontour SelectsLFeqoptions.±6dB.See

control figure19,topgraph

S4 Subwooferselectionswitch None,oneortwo.

S5 Subwooferfilterswitch Selectssubwooferfilterfrequency.

40Hz,50Hz,60Hz.

S6 LF/Subwooferfixedgain EnablesordisablesLFand

subwoofergainadjustment.

C3 LFGain AdjustsLFgain.

C4 Subwoofergain Adjustssubwoofergain.

S7 Parametricfilter Engagesnumberofparametricfilters

incircuit.None,one,twoorthree.

S8 P1Gain Selectsgainofparametricfilter1.

-6dB,-3dB,+3dB.

C5 P1Q AdjustsQofparametricfilter1

0.3 to 4.

C6 P1Freq Adjustsfrequencyofparametric

filter1.25Hzto500Hz.


-6dB,-3dB,+3dB.


0.3 to 4.




-6dB,-3dB,+3dB.


0.3 to 4.



16

LFContour

HF Contour

Figure 19


Figure 20

Figure 21

+ +

+ +

S1 T1 S2 S3

C1 C2

S5 S6S4

C3 C4

S7 S8

C5 C6

S9

C7 C8

S10

C9 C10

Figure 21

Setting the LF gain

Disconnectthespeakersfromthepoweramplifiers.

ConnecttheMF/HFpoweramplifiertotheLFoutputoftheunit.

Settheoutputleveloftheoscillatortozeroandconnectittothetestinput

socket T1. Select the test input by switching the input switch S1 to

“Test”.

Settheoscillatorfrequencyto100Hz.

EnableLFgainadjustmentbysettingswitchS6to“LF”.

ConnecttheACvoltmetertotheoutputterminalsoftheMF/HFamplifier.

Raisetheoutputleveloftheoscillatoruntilthemeterreads2volts.

SubstitutetheLFpoweramplfiierfortheMF/HFpoweramplfier.Donot

altertheoutputsettingoftheoscillator.

AdjusttheLFgaincontrol(C3)untilthemeteragainreads2volts.

Setting the subwoofer gain

Disconnectthespeakersfromthepoweramplifiers.

ConnecttheMF/HFpoweramplifiertotheSubwooferoutputoftheunit.

Settheoutputleveloftheoscillatortozeroandconnectittothetestinput

socket T1. Select the test input by switching the input switch S1 to

“Test”.

Settheoscillatorfrequencyto25Hz.

EnablesubwoofergainadjustmentbysettingswitchS6to“Sub”.

ConnecttheACvoltmetertotheoutputterminalsoftheMF/HFamplifier.

Raisetheoutputleveloftheoscillatoruntilthemeterreads2volts.

SubstitutetheSubpoweramplifierfortheMF/HFpoweramplifier.Donot

altertheoutputsettingoftheoscillator.

AdjusttheSubgaincontrol(C4)untilthemeteragainreads2volts.

17


Figure 20

Figure 21

+ +

+ +

S1 T1 S2 S3

C1 C2

S5 S6S4

C3 C4

S7 S8

C5 C6

S9

C7 C8

S10

C9 C10Figure 20

Equipment Required

ACvoltmeter•

Signalgeneratorcapableofoutputtingasinewaveupto2VRMS•

Smallandmediumsizeflatbladedscrewdriverstoselectthe•

switchpositionsandadjusttherotarycontrolsoftheCT8XO.

Andtoadjusttheequaliserstooptimisethein-roomresponse:

LaptopPCwithWinMLS2004(orlaterversion)softwareinstalled•

External sound card•

Measuringmicrophone•

WinMLS may be purchased directly from the software supplier, in

whichcaseitshouldbeWinMLS2004orlaterandbetolevel3license.

Itshouldalsoincludethespeciallycreated“B&WCT800”measurement

module.Earlyversionsofthesoftwaredidnotincludethismodule,but

thelatestversionmaybedownloadedfromwww.winmls.com.

However,aspecialpackagethatincludesasuitablemicrophone,USB

sound card and a cut-down version of the software that includes

everything required for tuning a CT800 system may be obtained

directlyfromB&W.Contactyourcountrydistributorfordetails.

TheseillustrationsonthefollowingpagesrefertotheB&Wversionof

thesoftware.Thestandardversionwilldifferslightly.

Configuring the CT8 XO to the speaker

SetswitchS2toselectthetypeofspeakerassignedtotheCT8XO.Ifthe

speakerassigned isasurroundspeaker,setswitchS3toselect leftor

rightdipolesasappropriatetoeachspeaker’spositionintheroom(figure

21).ifthesurroundspeakersaretobepermenantlyinmonopolemode,

thepositionofswitchS3isimmaterial.

Set switch S4 to select the number of subwoofers connected to the

CT8 XO.

SetswitchS5toselectthesubwooferfilterfrequency.SettheS5initially

to50Hz.The40Hzor60Hzoptionsmaybeselectedifappropriatewhen

finetuningtheinstallation.

Configure the unit to the gain of each power amplifier

During this process, theparametric equalisers shouldbebypassedby

settingswitchS7to“None”andtheLFandHFcontourcontrols,C1and

C2,settozero.

Configure the Equalisers

Sensiblecorrectionofthein-roomresponserequirestheabilitytomeasure

the acoustic frequency response of each speaker individually. The

measurementmicrophonedoesnotneedtobeexpensiveandsuitable

electretmicrophonesarewidelyavailable. If theappropriatemeasuring

equipmentisnotavailable,werecommendthattheparametricfiltersbe

bypassedbysettingswitchS7to0.Settingofthelow-andhigh-frequency

contourcontrolsmaybeattemptedbyeartotheuser’spreference.

Correctingforroomresonancesrequiresthought,skillandpatience.Itis

notsensibletoattempttofullyequaliseresponsedips,asthismayleadto

systemoverload.Fortunately,dipsarelessobjectionablethanpeaks.For

this reason,eachparametricfilterallows just3dBofboost,but6dBof

cut.

It is also not advisable to make corrections to a single position

measurement.Theresponseofthespeaker/roomcombinationcandiffer

considerably throughout the room and it is all too easy toworsen the

responseinonepositionwhilstmakingitbetterinanother.Anaverageof

severalmeasurements takenatdifferentpositionsthroughout theroom

should ideally be used to ensure an overall improvement in all listener

positions.

The Method

Wesuggest takingmeasurementsateachseatpositionandatseveral

pointsoutsidetheimmediatelisteningarea.Pointthemicrophonetowards

thespeakerbeingmeasured.

Theresonanceschangewithheight.Oftenseatswillbeatthesamelevel,

soputthemicrophoneatatypicalearheight.Ifthehometheatreroomis

likeaminicinemawith regular rowsof rakedseating,measureateach

seat at the likely ear height. Do not hand hold themicrophone during

measurements.Useatripodorothermeansofholdingitstill.Itisadvisable

to make the last measuring position n (the one used for subsequentequalisedmeasurements)theprimarylisteningposition.

Procedure

To avoid errors from airbourne background noise and electrical

interference,switchoffallsourcesintheroomsuchasairconditioning,

refrigerators etc.

SelectthetestinputbyswitchingtheinputswitchS1to“Test”.

SettingswitchS7to“None”todisabletheparametricequalisersandset

theLFandHFcontourcontrols,C1andC2,settozero.

Connecttheoutputofthesoundcardtothefronttestinputsocketofthe

CT8XOandthemicrophonetotheinputofthesoundcard.

OpenWinMLS2004

Fromthemenu,selectSetup…Load… andloadthesetupcalled“B&W

CT800”fromthe“SoundSystem”folder.

Clickthebuttontoopenthe“VolumeandInputLevels”window.

18

Laptop computer settings:

Runthelaptopfromitsbatteryanddisconnectitstransformerpower

supply when taking measurements. This will prevent noise being

generated by electrical groundingmismatches between the laptop,

soundcardandCT8XO.Makesurethebatteryisfullychargedbefore

startingthemeasuringprocedure.

Open the “Sounds and Audio Devices” window in “Control Panel”.

Clickon the “Sounds” tabandselect the “NoSound”option in the

“SoundScheme”drop-downmenu.

Click on the “Volume” button in the “Sound Playback” section and

make sure the Microphone “Mute” box is checked to prevent

feedback.

Clickonthe“Audio”tabandthenonthe“Volume”buttoninthe“Sound

Recording”section.Setthevolumeslidertomaximumandmakesure

the“Select”boxischecked.

Figure 22

Placethemicrophoneatthechosenmeasurementpositionthatisclosest

tothespeakerundertest(whereitwillmeasurethehighestsoundpressure

level).Setthe“InputCh.1”slidertomaximum.

Set the “Output” slider to zero and switch on the test signal by

clickingthebutton.Increasetheoutputleveluntilthe“InputCh.1”

levelmeter justgoesintotheredzone.Decreasethe“InputCh.1”level

untilthesignalpeaksbetweenthe-6dBand-3dBmarks.

Closethe“VolumeandInputLevels”windowandclick thebutton to

switchoffthetestsignal.

Make sure Plot…Overlay is checked to show the frequency response

screenandenableseveralresponsestobeviewedsimultaneously.

PresstheF7keytobringuptheMeasurementSettingswindow.Inthe

‘‘Levels’’box,setthesinesweepto-40dBFS(fullscale).

Performanumberofmeasurementsindifferentpositionsbyclicking

the button (or pressing the F2 key). Make the last measurement

youtakeclosetothecentreofthelisteningareaandleavethemicrophone

exactlyinthatpositionforsubsequentmeasurements.

Since Plot…Overlayischecked,thecurveswillbeplottedontopofeach

otherand,whenfinished,therewillben curves displayed.

Intheexampleshowninfigure22,n = 10.

Clickthebuttontodisplaythemeanvalueontopofalltheplotted

curves.Theaverageroomresponseisthencalculated(figure23).This is

the response we want to equalise.

Un-tickalltheplotsexceptthemeanresponse.(figure24)

Press CTRL+ E tosavethismeanresult in the“TuneEQ” folder (if this

folderdoesn’texist,create it inC:\ProgramFiles\WinMLS2004\SetEQ).

ThenclickSave andnamethefile,forexample,Average_resp.txt

(figure25)

19

Figure 23

Figure 24

Figure 25

Tosetthiscurveasamultiplier,presstheF5key.Inthisdialogbox,select

the file you just saved (Average_resp) and, under ‘Compensation of

Level’, check the ‘Tune EQ (multiply)’ box as shown (figure 26). This

curve is now the reference and all subsequent measurements will be

multipliedbythisresponse.

ClickOK.Thegraphswillchange,butignorethesechanges.

Wenowneedtosetdivisionbythemeasurementperformedinthislast

positionwithnoequalisation(Rn ).

Press Ctrl + Fandmakesurethislastmeasurementisselectedasshown

infigure27(inthisexample#10wasthelastmeasurementpositionand

thatisthereforesetasreference).

Click OK.

Thegraphswillchange,butignorethesechanges.

When we now perform another measurement with the equalisation

applied (Rneq ),thesoftwarewillcalculatethequantity:Rmeq =

Rneq .RmRn

Inourcasetheoriginalmeasurementatposition#10isRn.

Nowitistimetocleanupthedisplay.Makesurethefollowingbuttonis

turnedoff:

Toremovethemeasurementsweusedtomakethereference,clickthe

erase button and select the settings shown in figure 28 (this will

remove all the curves in the plot and remove themeasurements from

memory).

Therewillnowbenoplotsshowingonthescreen.Makesurethe

Overlaybutton isinthedownstate.

Click (orpress theF2key) to re-measure the responseat the last

position.This timeon thescreen,youwillbepresentedwith themean

response.

Examinethismeanresponseandconsidertheoptimumtargettoaimfor.

Aflatin-roomresponseisnotdesirable.Studiesshowthatamoresuitable

targetisaresponsethatisflatupto100Hzandthenfallinguniformlybya

totalof6dBby10kHz.

Tunetheparametricfiltersfirstbeforeusingthelow-andhigh-frequency

contour controls.

Therearethreefilters,eachhavingadjustablecentrefrequency,gainand

Q.Aimtosuppresspeaksfirst.Onlyiftherearefewerthanthreesignificant

peaksshouldyouconsiderfillingindips.

20

Figure 26

Figure 27

Figure 28

Specifythenumberofparametricfiltersrequiredbyselecting“1”,“2”or

“3”onswitchS7.

Themarkingsonthefiltercontroldialsareapproximateandforguidance

only.

Settheindividualfiltergaincontrols(S8,S9&S10)to-6dB.

SettheindividualfilterQcontrols(C5,C7&C9)to4.

Thisenablesthecentrefrequencyresponseofthefilterstobeseen.

Settheindividualfilterfrequencycontrols(C6,C8&C10)initiallyto25Hz.

Thiskeepsthefiltersawayfromthefrequencyrangeofinterestuntilthey

aretunedoneatatimetocompensatethefrequencyresponse.

NOTE:

TheP1,P2andP3frequencycontrolsworkcounter-clockwisetoallowfor

ease of setting.

Turnthefilterfrequencycontrols(C6,C8&C10)tothecentrefrequencies

of the peaks or dips to be equalizsed. This is an approximate initial

setting.

Takerepeated frequency responsemeasurements tosee theeffectsof

theadjustmentsyouareabout tomake. Everynowandthenyoumay

wishtodiscardplotsandthismaybedonebyuncheckingthoseyoudo

notneedontheplotlisttotherightofthescreen.

Adjustthefiltercentrefrequenciesuntilthemeasureddipsintheresponse

lineupaccuratelywiththecentresof thepeaksordipsoriginally in the

response.

Adjustthefiltergainswitches(S8,S9&S10)sothattheresponseatthe

centrefrequencyofeachfilterisatthetargetlevel(thedesiredsmoothed

level).

LowerthefilterQcontrols(C5,C7&C9)tobroadentherangeofthefilters

untiltheresponseisassmoothaspossible.

Thecontrolsaretosomeextentinteractiveanditmaybeworthwhilegoing

roundtheloopofcheckingthecontrolsettingsasecondtime.

AdjusttheLFandHFcontourcontrols,C1andC2,asappropriate.

Additional low frequency response adjustment may be achieved by

alteringthesubwoofergain(C4)andfilterfrequency(S5).Additionallow/

midfrequencyadjustmentmaybeachievedbyalteringtheLFgain(C3).

If you need to equalise another speaker, you must reload the CT800 setup within WinMLS and repeat the above process.

21

Running In and Ancillary Equipment

Ancillary Equipment

Speakersofthisabilitydeservesignalsofthehighestquality.Chooseyour

electronicequipmentandinterconnectingcableswithcare.Wecangive

guidance onwhat to look for when choosing ancillary equipment, but

cannotrecommendspecific items.Thestandardsofsuchproductsare

improvingallthetimeandyourdealerwillbeabletodemonstrateavariety

ofsuitableup-to-dateproducts.

In the specification we recommend a range of amplifier powers. The

higherfigureisdefinedbythepowerhandlingcapabilityofthespeaker.

Whencalculatingthepowerhandling, it isassumedthattheamplifier is

notrunintoclipping,whichdistortsthefrequencypowerspectrumofthe

signal,andthatthesignalisnormalprogrammematerial.Testtonesfrom

oscillatorsandthelikearenotapplicable.Thelowerfigureistheminimum

we consider necessary to achieve reasonable listening levels without

audibledistortioninthesmallerroom(lessthan60m3or2000cuft).The

higherthepoweryouuse,thelesslikelyyouaretoexperienceamplifier

clipping.

Youcanoften tellhowgoodanamplifier isatdrivingcomplexspeaker

loadsbylookingatitspowerratingintoboth4Ωand8Ωloads.Thenearer

theratioisto2:1thebetter,asitindicatesagoodcurrentcapability.

Inordertoreducetheeffectthecablehasonthefrequencyresponseof

the speaker to inaudible levels, the impedance of the cable at all

frequencies(measuringbothpositiveandnegativeconductorsinseries)

should be kept as low as possible and certainly below 0.1Ω. At low

frequencies,theDCresistanceofthecableisthedominantfactorandyou

should choose a gauge of wire sufficient to achieve the impedance

requirementsoverthelengthofcableyouneedtouse.Atmidandhigh

frequenciestheinductivecomponentoftheimpedancecandominatethe

DC resistance. This and other properties influenced by the detailed

constructionofthecablebecomeimportant.

Running In

The performance of the speakers will change subtly during the initial

listening period. If they have been stored in a cold environment, the

damping compounds and suspension materials will take some time to

recovertheircorrectmechanicalproperties.Thedriveunitsuspensions

willalso loosenupduring thefirsthoursofuse.The time taken for the

speakers toachievetheir intendedperformancewillvarydependingon

previousstorageconditionsandhowtheyareused.Asaguide,allowup

toaweekforthetemperatureeffectstostabiliseand15hoursofaverage

use for the mechanical parts to attain their intended design

characteristics.

However,longerrun-inperiods(aslongasamonth)havebeenreported

andthereisevidencetosuggestthatthishaslittletodowiththespeaker

changingandmoretodowiththelistenergettingusedtoanewsound.It

isespeciallysowithhighlyrevealingspeakerssuchasthese,wherethere

maybeasignificantincreaseintheamountofdetailportrayedcompared

towhatthelistenerhaspreviouslybeenusedto;thesoundmayatfirst

appeartoo“upfront”andperhapsalittlehard.Afteranextendedperiod

of time, the sound will seem tomellow, but without losing clarity and

detail.

Aftercare

ThespeakercabinetsurfacesandthecasingoftheCT8XOusuallyonly

requiredusting.Ifyouwishtouseanaerosolcleaner,removeanyspeaker

grillesfirstbygrippingroundtheedgesandgentlypullingthemawayfrom

thecabinet.Sprayontothecleaningcloth,notdirectlyontothecabinet.

Thegrille fabricmaybecleanedwithanormalclothesbrushwhilst the

grilleisdetachedfromthecabinet.

Whenreplacinggrilles,ensurethatthepegsarecorrectlyalignedwiththe

receptaclesinthecabinetbeforepushingintoplace.

Avoid touching the drive unit diaphragms, especially the tweeter, as damage may result.

22

Aftercare

Specifications

23

Model CT8 LR CT8 CC

Description 3-wayclosed-boxsystem 3-wayclosed-boxsystem

Drive Units 1xØ32mm(1¼in)metaldomehigh-frequency

1x Ø150mm (6 in) woven Kevlar® cone FST™ midrange

2xØ250mm(10in)Rohacell®conebass

1xØ32mm(1¼in)metaldomehigh-frequency



Frequency Range -6dBat23Hzand40kHz -6dBat23Hzand40kHz

Frequency Response 29Hz-24kHz±3dBonreferenceaxis 29Hz-24kHz±3dBonreferenceaxis

Dispersion Within2dBofreferenceresponseHorizontal: over 60º arc

Vertical: over 10º arc

Within2dBofreferenceresponseHorizontal: over 60º arc


Sensitivity 93dBspl(2.83V,1m)(mf/hf) 93dBspl(2.83V,1m)(mf/hf)

Harmonic Distortion 2ndand3rdharmonics(90dB,1m)

<1%45Hz-20kHz

<0.5%55hZ-20kHz

2ndand3rdharmonics(90dB,1m)

<1%45Hz-20kHz

<0.5%55hZ-20kHz

Nominal Impedance 8Ω(minimum4Ω) 8Ω(minimum4Ω)

Crossover Frequency 300Hz,4kHz 300Hz,4kHz

Recommended Amplifier Power 500W-1000Winto8Ωonunclippedprogramme 500W-1000Winto8Ωonunclippedprogramme

Max Recommended Cable Impedance 0.1Ω 0.1Ω

Dimensions Height: 1100mm(43.3in)(withoutspikefeet)

Width: 325mm (12.8 in)

Depth: 550mm (21.65 in)

Height: 325mm(12.8in)(withoutspikefeet)

Width: 1100mm (43.3 in)

Depth: 550mm (21.65 in)

Weight 85kg(187lb) 85kg(187lb)

Finish Cabinet:Black Cabinet:Black

24

Model CT8 DS CT8 SW

Description 3-waymonopole/2-waydipoleselectableclosed-box

surround system

Closed-boxsubwoofer

Drive Units 1xØ32mm(1¼in)metaldomehigh-frequency

6xØ100mm(4in)midrange/high-frequency



1xØ380mm(15in)carbonfibre/Rohacell®sandwichcone

bass

Frequency Range -6dBat26Hzand40kHz(monopolemode)

-6dBat26Hzand22kHz(dipolemode)

-6dBat13Hzand40kHz

Frequency Response 31Hz-22kHz±3dBonreferenceaxis(monopolemode)

31Hz-18kHz±3dBpoweraveragedoverfronthemisphere

(dipole mode)

18Hz-35kHz±3dBonreferenceaxis

Dispersion Monopolemode:Within2dBofreferenceresponseHorizontal: over 60º arc


Dipolemode:horizontalfigureofeight

Effectivenullzone±30°(250Hz-18kHz)

Within2dBofreferenceresponseHorizontal: over 90º arc


Sensitivity 93dBspl(2.83V,1m)(mf/hf) 90dBspl(2.83V,1m)(mf/hf)

Harmonic Distortion 2ndand3rdharmonics(90dB,1m)

<1%45Hz-20kHz

2ndand3rdharmonics(90dB,1m)

<1%30Hz-500Hz

<0.5%45Hz-300Hz

Nominal Impedance 8Ω(minimum4Ω) 8Ω(minimum4Ω)

Crossover Frequency 300Hzand4kHz(monopolemode)

300Hz(dipolemode)

40Hz

Recommended Amplifier Power 500W-1000Winto8Ωonunclippedprogramme 500W-1000Winto8Ωonunclippedprogramme

Max Recommended Cable Impedance 0.1Ω 0.1Ω

Dimensions Height: 1100mm(43.3in)(withoutspikefeet)


Depth: 250mm (9.85 in)

Height: 475mm(18.7in)(withoutspikefeet)



Weight 75kg(165lb) 35kg(77lb)

Finish Cabinet:Black Cabinet:Black

25

Model CT8 XO Mk 2

Description CT800systemactivebassmanagementcontroller

Functions Bass/midrange crossover

Subwoofer/basscrossover

Low-frequencyroll-offalignment

Highfrequencyroll-offalignment

3 parametric equalisers

Subwooferin/out

Leveladjustmentfornumberofsubwoofers

12Vtriggerswitchingforsurroundmode

Inputs LineIn(XLR)

12Vtrigger(3.5mmjack)

Outputs MF/HFLineOut(XLR)

LFLineOut(XLR)

SubwooferLineOut(2xXLR)

12Vtrigger(3.5mmjack)

Rated power consumption 20W

Dimensions Height: 44.5mm(1.75in)1U

Width: 483mm (19 in)


Weight 3kg(6.6lb)

Finish Frontpanel:AnodisedAluminium

Chassis:Black

Copyright © B&W Group Ltd. E & OE

Kevlar is a registered trademark of DuPontRohacell is a registered trademark of Röhm GmbH

Printed in Canada.Issue 5

UK Group (UK Sales)T +44 1903 221 500E [email protected]

B&W Group North AmericaT +1 978 664 2870 E [email protected]

B&W Group (Asia) LtdT +852 2 869 9916E [email protected]

B&W Group Ltd Dale Road Worthing West Sussex BN11 2BH England

T +44 (0) 1903 221 800 F +44 (0) 1903 221 [email protected] www.bowers-wilkins.com

Documents

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