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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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
Figure 2 Figure 3
Figure 4
Figure 5
~40o
~120o
~60o
Figure 7
Figure 6
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
Figure 2 Figure 3
Figure 4
Figure 5
~40o
~120o
~60o
Figure 7
Figure 6
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 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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
Figure 9
Figure 10 Figure 11
SUB +
SUB -
SUB +
SUB -
Figure 15
Figure 16a Figure 16b
Figure 17
Figure 14
CT8 XOFigure 8
Figure font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
Figure 9
Figure 10 Figure 11
SUB +
SUB -
SUB +
SUB -
Figure 15
Figure 16a Figure 16b
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
Figure 9
Figure 10 Figure 11
SUB +
SUB -
SUB +
SUB -
Figure 15
Figure 16a Figure 16b
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
Figure 9
Figure 10 Figure 11
SUB +
SUB -
SUB +
SUB -
Figure 15
Figure 16a Figure 16b
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.
S9 P2Gain Selectsgainofparametricfilter2.
-6dB,-3dB,+3dB.
C7 P2Q AdjustsQofparametricfilter2
0.3 to 4.
C8 P2Freq Adjustsfrequencyofparametric
filter2.25Hzto500Hz.
S10 P3Gain Selectsgainofparametricfilter3.
-6dB,-3dB,+3dB.
C9 P3Q AdjustsQofparametricfilter3
0.3 to 4.
C10 P3Freq Adjustsfrequencyofparametric
filter3.25Hzto500Hz.
16
LFContour
HF Contour
Figure 19
Figure font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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 font: Helv 45, 7ptFigure spacing: 7 x 7 mm
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
1x Ø150mm (6 in) woven Kevlar® cone FST™ midrange
2xØ250mm(10in)Rohacell®conebass
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
Vertical: over 10º 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
1x Ø150mm (6 in) woven Kevlar® cone FST™ midrange
2xØ250mm(10in)Rohacell®conebass
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
Vertical: over 10º arc
Dipolemode:horizontalfigureofeight
Effectivenullzone±30°(250Hz-18kHz)
Within2dBofreferenceresponseHorizontal: over 90º arc
Vertical: 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)
Width: 325mm (12.8 in)
Depth: 250mm (9.85 in)
Height: 475mm(18.7in)(withoutspikefeet)
Width: 475mm (18.7 in)
Depth: 475mm (18.7 in)
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)
Depth: 155mm (6.1 in)
Weight 3kg(6.6lb)
Finish Frontpanel:AnodisedAluminium
Chassis:Black
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Kevlar is a registered trademark of DuPontRohacell is a registered trademark of Röhm GmbH
Printed in Canada.Issue 5
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