OS DB7 User manual

User Guide
DB7

Contents
 ImportantSafetyInstrucons......................................Page3
 Introducon.................................................................Page5
 Operaon.....................................................................Page7
 ConnectorsandControls..............................................Page8
 DSPPresets..................................................................Page9
 Linear-PhaseTimeAlignment......................................Page10
 MonitorPlacement......................................................Page12
 TechnicalSpecicaons...............................................Page14
 WarrantyandService..................................................Page15
 ContactUs...................................................................Page16

• Readandfollowtheseinstruconscarefully,andretainthemforfuturereference.
• The DB7 is heavy (~12kg). Please take care when liing!
• Takecareunpackingyournewmonitors,beingcarefulnottotouchthedriveunits
• Pleaseretainthepackagingforsafetransportaoniftheneedforservicingarises.Ensure
packagingisstoredordisposedofsafelytoavoidposingarisktotheyoungandvulnerable.
• Donotusethisapparatusnearwater.
• Cleanonlywithadrycloth.Thecabinetnishmaybedamagedbysolvents,abrasives,waxes,
orliquids.
• Donotinstalltheloudspeakernearanyheatsourcessuchasradiators,heatregisters,stoves,
orotherapparatus(includingampliers)thatproduceheat.
• Donotcovertheheatsinkontherearpanel,orblockanyvenlaonopenings.
• Protectthepowercordfrombeingwalkedon,orbeingpinchedordamagedinanyotherway.
• Donotdefeatthesafetypurposeofthepolarizedorgrounding-typeplug.Apolarizedplughas
twobladeswithonewiderthantheother.Agroundingtypeplughastwobladesandathird
groundingprong.Thewidebladeorthethirdprongisprovidedforyoursafety.Iftheprovided
plugdoesnottintoyouroutlet,consultanelectriciantoreplacetheobsoleteoutlet.
• Apowerswitchislocatedontherearoftheloudspeaker.Themainscordisusedasamains
disconnectdeviceandshouldremainaccessibleatallmes.
• Unplugthisapparatusduringlightningstorms,orwhenunusedforlongperiodsofme.
• Donotplacetheproductonanunstablecart,stand,tripod,bracket,ortable.Thedevicemay
fall,causingseriousinjury,andseriousdamagetothedeviceitself.
• Onlyuseaachments/accessoriesspeciedbythemanufacturer.
• Referallservicingtoqualiedservicepersonnel.Servicingisrequiredwhentheapparatus
hasbeendamagedinanyway,includingbeingexposedtorain,spiltliquids,ormoisture,ofif
objectshavefallenintoit,ortheapparatushasbeendropped,orifthereisadisnctchangeof
audioperformance,oriftheunitdoesnotoperatenormally.
• VerypowerfulmagnetsareemployedintheDB7whichmayhaveadetrimentaleecton
magnecally-sensiveitemsandrecordingmediaifplacedtooclose.
• TheDB7isaprecisionaudiomonitoringtoolcapableofproducinghighsoundpressurelevels.
ImportantSafetyInstrucons

Exposuretohighlevelsofsoundovermehasthepotenaltocausehearingdamage.Use
carewhenadjusngthesystemvolumetoensuresoundpressurelevelsremainwithinsafe
andcomfortablelimits.
• Make sure that the audio source volume is set to minimum before powering the DB7 to
prevent sudden high sound levels. Failure to follow these instrucons may result in damage
to your hearing or to the DB7.
• O.SAcouscshasmadeeveryeorttoprovideaccurateinstallaoninformaonandgood
qualityxings.However,itwillnotbeheldresponsibleorliableforinjuriesorpropertydamage
(direct,indirect,orconsequenal)arisingoutoftheuse,orinabilitytousethisproductsafely
andproperly.
ImportantSafetyInstrucons

ThankyouforchoosingOSAcouscsDB7acvereferencemonitors.
TheDB7isconstructedusingcomponentsofthehighestqualityand,withtherightcareand
aenon,yournewloudspeakerswillprovidemanyyearsofexcellentaudioreproducon.
Asophiscateddigitalsignalprocessing(DSP)systemisbuiltintotheDB7toprovidea
newstandardinmingcoherenceandaccuracy.Designedwithacousctransparencyasa
priority,OSAcouscsDB7faithfullypreservesphaserelaonshipstopresentathree-dimensional
soundstage,andreproduceseverymbraldetailandharmonicnuancewithstunningrealism.
ProprietaryUMAC™Class-Dampliertechnologyfrommarket-leadingmanufacturerPascalAudio
oersunparalleled,extremeaudiophilesonicperformance,andboastsofthebestmeasurable
specicaonsinthemarket.TheDB7enjoysatotalof650Was(RMS)ofultra-lowdistoron
amplicaon,anditsabilitytodeliververyhighshort-duraonpowerburstsgivestheDB7an
exceponaltransientresponse.
ToguaranteemaximumreliabilitytheDB7alsofeaturesahighlyecientswitch-modepower
supplywithUREC™power-factorcorrecontechnology.ItsupportsuniversalACmainsoperaon,
ensuringconsistent,regulatedpowerworldwide,eliminangsuscepbilitytolocalpower-related
reliabilityissues.
Precision
Eachindividualloudspeakerdriveunitismeasuredduringproducon,andanyresponsedeviaons
arecorrectedbytheDSPtoaverynetolerance.Thisallowsanaccuratefrequencyandphase
responsecontrolledtoalevelofprecisiononlyobtainableusingDSP,providingtheDB7with
outstandinglinearity.
Itisessenalthatloudspeakershaveverycloselymatchedfrequencyresponsesforaccurateand
stableimagingincricalstereoandsurroundsoundapplicaons.Matchingindividualmonitorsso
preciselygivestheaddedadvantageofinterchangeabilitysothat,intheunlikelycaseofamonitor
breakdown,anotherDB7monitorcanbesubstutedwithcompletecondence.
Introducon

Frequency&PhaseResponse
ThepowerfuldigitalsignalprocessingbuiltintotheDB7enablesanalmostperfectlyaton-axis
frequencyresponse,asillustratedbelow(le-handscale),withanamplitudevariaonwithin±2dB,
and matchingbetweenanytwoloudspeakersofbeerthan0.5dB.
Digitalsignalprocessingalsoallowstheloudspeaker’sphaseresponsetobemaintainedwithin
ghttolerancesacrosstheenreaudiobandwidth,asshownbelow(right-handscale).Thephase
toleranceismaintainedwithin±15degreesbetween200Hzand20kHz.

Yourloudspeakersshouldprovidemanyyearsoftrouble-freeoperaonwithnormalusage.
However,intheunlikelyeventthatyoususpectdamageorfailurehasoccurred,donotaemptto
repairtheunityourself.Openingorremovingcoversmayexposedangerousvoltagesorotherhazards.
Theamplierchassismayonlybeopenedbyqualiedpersonnel.Therearenouser-serviceableparts
inside.Pleasecontactyourdealerforadviceandaservicereturnaddress.
Cleantheloudspeakercabinetsonlywithadryandlint-freecloth.Theuseofsolventsorabrasive
cleanersshouldbeavoidedastheywilldamagethenishofthecabinet.
Breaking-in Time
Ittakesmeforthemovingpartsofthetransducerstorelaxaermanufactureandreachopmum
compliance.Asaresult,youwillnoceasignicantimprovementinthesoundqualityaeraperiodof
useofabouteighthours,withgreaterbassextensionandamoreneutraltonality.Addionally,more
subtleenhancementswillbenocedduringtherstweekofuse.
Standby Mode
TheDB7willswitchtoapower-savingstandbymodeautomacallyifnosignalhasbeendetectedfora
periodof15minutes.Thestandbymodeuseslessthan0.2Was,makingitEnergyStarcompliantand
inaccordancewiththeErP(1275/2008/EC)direcve.
Thesystemwakesfromthisstandbymodeautomacallywhenanaudioinputsignalisdetected,
typicallyregainingnormaloperangstatuswithin660milliseconds.Dependingonthesourcematerial,
youmayndoneloudspeakerwakesfraconallybeforetheother,orthatslightlymoresignallevelis
requiredtoreachthe‘wake-up’thresholdandre-acvatetheloudspeakers.
Limiter
TheDB7’sDSPsystemincorporatessophiscatedlimitersdesignedtoprotectthetransducersfrom
damagebyover-excursion.Theyalsokeepthevoice-coiltravelwithintheopmumworkingrange,and
avoidthermaloverload.AnLEDontherearpanelilluminateswhentheprotecvelimiterisacvated.
Operaon

Connectors and Controls
1.Power–illuminatesgreenwhenthemonitor
isreceivingmainspower.
2.Limit–illuminatesorangewhenthelimiteris
acvated.
3.Signal/Clip–illuminatesbluewhenanaudio
signalispresentandaboveapresetthreshold.
TheiIlluminaonchangestorediftheinput
levelreachestheclippingpoint.
4.InputGaincontrol–Providesanadjustable
sensivityrangeof-30dButo0dBu.Itis
recommendedtooperatetheloudspeakerswith
thecontrolatthe0dBuposionwherepossible,
controllingthevolumefromthesoundsource.
5.PresetSelectcontrol–Eight-posionrotary
switch.See‘DSPPresets’formoreinformaon.
6.AnalogueaudioinputfemaleXLRconnector.
7.LinkOutputmaleXLRconnector.
8.DualRJ45dataconnectorsformanufacturer
accessonly.
9.IECmainsinlet:85to265VAC,50/60Hz
10.Poweron/oswitch.
1 4
3
2
5
6
78
9 10
Preset Select Control Summary
Preset Response LP RBC Preset Response LP RBC
1Flat 5Flat X
2Voiced 6Voiced X
3Flat X 7 Flat XX
4Voiced X 8 Voiced XX

TheDB7canbeconguredfordierentinstallaonsituaonsandpreferencesusinganyofeight
factory-programmedDSPpresets.Thesearerecalledusingthe‘PresetSelect’rotaryswitchatthe
rearoftheloudspeakernearthetopoftheamplierchassis.
Preset 1providesanopmally‘Flat’response(±2dB).Thismodeisdesignedforcompleteaccuracy
anddeliversanincrediblyneutral,uniformfrequencyresponse.
Preset 2isa‘Voiced’seng,whichisnotasaccurateasPreset1,butdeliversaslightlysmoother
andmorerelaxedacouscpresentaon.
Preset 3isalinear-phaseversionofPreset1(Flat).
Preset 4 isalinear-phaseversionofPreset2(Voiced).
Loudspeakersarenotnaturallylinear-phase,whichmeansthatthereproduconoflow
frequenciesisinherentlyslightlydelayedcomparedtohighfrequencies.Presets3and4
imposealinear-phaseresponsetorealignthemingcoherencebetweenallfrequencies.This
enhancesspacialinformaon,renestransients,andimprovestherelaonshipbetweenthe
fundamentalsandharmonicsofinstruments.Thelinear-phasemodeisconguredtoworkbest
whenlisteningonthedirectaxisofthetweeter.
NOTE:Allofthelinear-phasemodesimposeanaddionalve-millisecondprocessingme
throughtheDSP.
Preset 5isthesameasPreset1(Flat),butwithRoomBoundaryCorrecon(RBC)applied.
RBCcanbeselectedtocounterthebass-loadingeectontheloudspeakerduetotheproximity
ofoneormorelocalboundaries.Generallyspeaking,thecloseraloudspeakeristoawallorto
thecornerofaroomthemorethelowfrequenciesareboosted.TheRBCmodecompensates
forthiseectbyreducingthelow-frequencyoutputfromtheloudspeaker.
AnotherfactoraecngthechoiceofwhetherornottouseRBCcouldbe‘roommodes’which
causereinforcementsandcancellaonsofthelow-endresponseatdierentpointswithin
theroom.Allroomsaectthereproducedsounddierently,andsoRBCmightnotalwaysbe
neededevenifthemonitorsareposionedinthecornersofaroom.Pleaseexperimenttosee
whatmodeworksbestinyourspeciclisteningenvironment.
Presets 6 (Voiced), 7(L-PFlat), and 8(L-PVoiced)allhaveRBCapplied,butareotherwisethesame
asPresets2,3and4,respecvely.
Asummarytabledenongallofthedierentpresetoponscanbefoundonpage8.
DSPPresets

Linear-PhaseAlignment
Phase
Allsoundfrequenciestravelatthesamespeedthroughair,maintainingacoherentarrivalme
atthelisteningposion.Unfortunately,though,thesamecannotbesaidofaudiothatisplayed
backthroughaloudspeakersystem.Virtuallyallloudspeakersintroducephaseerrors,distorng
themingcoherencesothatsomefrequenciesaresmearedacrossmeanddelayedcomparedto
others.Thiscanbethoughtofasafrequency-dependentdelay.
Accuracy
Toreproduceacomplexwaveformprecisely,theplaybackdeviceneedstoperformaccurately
inboththefrequency-domain(sothateachpitchisrecreatedatthecorrectamplitude)andthe
me-domain(sothateachnotearriveswhenitshould).Thelaerrequirestheloudspeakerto
maintaintheoriginalphaseormerelaonshipsbetweendierentsoundcomponentsasclosely
aspossible.
Coherence
Correconofthesefundamentalme-alignmentproblemsinconvenonalloudspeakersisn’t
praccaloraordableusinganaloguetechniques.However,theadvanceddigitalsignalprocessing
employedintheDB7allowsthephaserelaonshipsandmingcoherenceofthesourceaudiotobe
properlyandpreciselyrestored.
A New Standard
Theme-domainresponseofaloudspeakercanbeunderstoodbyexaminingwhathappensto
aperfectspike-likesignalofveryshortduraon,knownasaunitaryimpulse(Diracdelta)which
containsallfrequenciesalignedinaxed,uniformphaserelaonship.Thisistheme-domain
equivalentofaperfectlyatfrequencyresponse.Themeasuredoutputfromaloudspeaker
reproducingthisunitaryimpulseiscalleditsImpulseResponse.
Thele-handgraph(redtrace)onthenextpageshowsaloudspeaker’suncorrectedimpulse
responsewhichhasbeensmearedoutintime.Incontrast,theright-handgraph(yellow
trace)showstheimpulseresponseaerphase-correconhasbeenapplied.Theimpulseisoset
towardstheright-handsideofthegraphbecauseofthevemillisecondprocessinglatencyinher-
entinachievingalinear-phaseme-domainresponse.However,theimportantpointisthatthe
smeared-outcharacteriscseenintheuncorrectedimpulseresponsehasbeenremoved,andthe
correctedme-domainresponsemoreaccuratelyrepresentstheunitaryimpulseinputsignal.

The Importance of Time Alignment
Thesensivityofthehumanear,andthebrain’sabilitytodecodesoundinformaon,shouldnot
beunderesmated.
Forexample,theverysmalldierenceinthearrivalmesofacouscvibraonsateachear
(knownastheinterauralmedierence)isessenalforidenfyingthepreciselocaonofa
soundsourceinthespacearoundthelistener.Thesespaalinformaoncuesarevastlyimproved
whentheDB7loudspeakerisoperatedinitslinear-phasemode,presenngamuchmorevivid
andlife-likesoundstage.
Timbralinformaonisalsomorenaturallypreserved,avoidingthepotenalsituaonwhere
harmonicscanarriveaheadofthefundamentalinme .Chordswithshortandwell-denedstart
andendpointsbecomelessblurred.Transients–whicharecricalforrealismandpunch–are
reproducedmorefaithfullyresulnginabeersenseofnaturaldynamicsandmusicalrhythm.
NOTE:Thefrequencyresponseisnotaectedbyadopngthelinear-phasemode,whichiswhy
therearedierentpresetsfortheatandvoicedfrequencyresponseopons.Notallplayback
materialwillemphasiseorbenetfromthemoreaccurateme-domaincharacteriscsofthe
linear-phasemodestothesamedegree.
A typical loudspeaker impulse response A corrected linear-phase impulse response.
Linear-PhaseAlignment

Boththemonitorplacementandtheroomacouscshaveasignicantinuenceonperceived
soundqualityoftheloudspeakers.Pleasereadtheseconsbelowwhichwillassistinrealisingthe
bestpossibleperformancefromyourmonitorloudspeakers.
Room Acouscs
Loudspeakerstypicallyradiatelowfrequenciesomnidireconally.Asageneralruleofthumbthe
closerthespeakersareposionedtoreecvesurfaces,likeawall(oneboundary)orinacorner
(twoorthreeboundaries),themorethebassisreinforcedandamplied.TheOSAcouscsDB7
loudspeakersarefront-portedandcanbeplacedrightupagainstawall,ifnecessary,providing
sucientspaceisavailableforthepowerandaudiocablestobeconnected.
However,ifthebassreproduconbecomestoopowerfulwiththiskindofplacement,therearea
fewopons.Ideally,theloudspeakerscouldbemovedawayfromthereecvesurface,butifthat’s
notpossibleoneoftheRBCmodescouldbeselected(seeDSPPresetsformoreinformaon)which
willreducethebassresponseoftheloudspeaker.Theprofessionalstudiosoluonwouldbeto
installmoreacousctreatment–specicallymorebasstraps.
Posioning
Whenmovingtheloudspeakerawayfromawallboundaryitisrecommendedthatthefront
baffleshouldeitherremainwithinonemetreofthebackwall,orbemorethanfourmetres
awayinlargerrooms.Thesedimensionsarenecessarytoreducetheeectsofdestrucvecomb-
lteringorspeaker/boundaryinterferenceofthelow-frequencyresponse.
Foropmumresultsitisrecommendedthatthemonitorsareposionedequidistantfromthe
listeningposion,meaningthedistancestotheleandtherightmonitorsisidencaland–for
properstereomonitoring–themonitorsshouldalsobethatsamedistanceapartfromeachother.
Thismeanstheywillsubtendanangleofapproximately±30 degreeseithersideofthelistening
posion.Astablestereoimageishelpedbygoodle-rightsymmetrywithintheroom,andthis
appliestobothastereosetupandforthele-rightfrontmonitorsinamul-channelsetup.
Ideally,theloudspeakerheightshouldbesuchthatthetweetersareclosetoearheightor,in
situaonswherethisisnotpossible,theloudspeakershouldbetiltedsothatthetweeteris
pointingdirectlytowardstheearposition.
MonitorPlacement

Orientaon
Itisrecommendedtousetheloudspeakersintheirvercalorientaon.Thisprovidesthelargest
‘sweetspot’areawherethestereoimageisstableandthefrequencyresponseisaccurate.
Ifvercalorientaonisnotpossibleorisimpraccal,theloudspeakerscanbeusedhorizontally.
However,the‘sweetspot’ismuchsmallerinthisconfigurationandfrequencyresponse
cancellaonsaroundthecrossoverfrequencycanoccurthemoreyoumoveoaxis(leandright).
Stands
Thestructuresupporngaloudspeakerformspartofthecompleteloudspeakersystem,andthe
soundfromaloudspeakerisneverindependentofitsmounngcondions.Therefore,heavy-duty
standswhichholdtheloudspeakerstableinspacearerecommended.
Desktops
Assoundradiatesfromtheloudspeaker,theearly-orrst-reeconsfromanynearbysurfaceswill
negavelyimpactboththesoundqualityandyourenjoyment.Ifthemonitorspeakersareplaced
directlyonaworkstaon,therstreeconsareusuallyfromthedesksurfacedirectlyinfrontof
theloudspeaker.Inthissituaon,itishighlyrecommendedthatdeskstandsbeusedtobothraise
theheightoftheloudspeakersandtoacouscallydecouplethemfromthedeskstructure.Asa
result,thedestrucverst-reeconswillbereduced,aswillanysympathecresonanceswithin
thedesk,signicantlyimprovingtonalityandtheaccuracyoftheloudspeakers.
MonitorPlacement

Specicaons
Frequency Response 40Hz-20kHz(±2dBabove65Hz)
DB7PerformanceConsistency Matchedtowithin0.5dB
DesignPrinciple 2-WayFront-PortedReex
Tweeter 1”CeramicCoatedMagnesium
Woofer 6.5”Aluminium
Crossover 2.1kHz
PhaseTolerances ±15degrees(200Hz-20kHz)
THD(90dBat1m) Lessthan1%(75Hz-20kHz)
MaxSPL 105dBSPL
Dimensions(HxWxD) 403x208x437mm
Weight 11.80kg
Amplier: Class-DUMAC™withultra-lowdistoron
Power 500WRMS(woofer)+150WRMS(Tweeter)
Signal-to-NoiseRao >120dB(A-weighted,20Hz-20kHz)
THD+N(typicaluse) <0.05%(20Hz-20kHz,3dBbelowratedpower)
PowerSupply UREC™Universalmainsswitch-modewith
PowerFactorCorrecon
OperangMainsVoltage UniversalMains:85-265VIECC14inlet
StandbyMode EnergyStarandErPcompliant
DigitalConversion 24-bit,96kHzCirrusLogicConverters
AnalogueInput BalancedXLR.Adjustablesensivity:-30to
0dBu
DSPPresets 8(Flat,Voiced,Linear-Phase,andRBCopons)
Specicaonssubjecttochange

WarrantyAndService
OSAcouscsproductsarebuilttoveryhighstandardsand,undernormaloperaon,willprovide
manyyearsofexcellentperformance.
OSAcouscsproductsarewarrantedtobefreefromdefectsincomponentsandfactoryworkmanship
foraperiodoftwo(2)years.
IntheunlikelyeventofamonitorbreakdownpleasecontactyourlocalauthorisedOSAcouscs
dealer/distributor.Ifyoudonothavealocalrepresentavepleasevisitwww.os-acouscs.co.uk
andclickon‘Contact’tomessageOSAcouscsdirectly.
OSAcouscsshallnotberesponsibleforanyincidentalorconsequenaldamages.
OSAcouscs’responsibilityislimitedtotheproductitself.OSAcouscsassumesnoresponsibility
foranylossduetocancellaonofanyevents,orrentofreplacementequipment,orcostsdueto
thirdparty’sorcustomers’lossofprot,oranyotherindirectcostorlosseshoweverincurred.
OSAcouscsreservestherighttomakechangesorimprovementsindesignormanufacturing
withoutassuminganyobligaontochangeorimproveproductspreviouslymanufacturedand/orsold.
Unitsonwhichtheserialnumberhasbeenremovedordefacedmaynoteligibleforwarrantyservice.
Thiswarrantyshallbenullandvoidiftheproductissubjectedtorepairworkoralteraonbya
personorfacilityotherthanthoseauthorisedbyOSAcouscs.

OS Acouscs Ltd,
BournemouthInternaonalAirport,
4BrackleyClose,
Bournemouth
BH236SE
Tel:08452990213
info@os-acouscs.co.uk
www.os-acouscs.co.uk
www.facebook.com/osacouscs
www.instagram.com/osacouscs
Contact Us

Copyright2020
DocumentproducedbyApple&PearProduconsLtd.

O.SAcouscs  DB7Manual  Version1.2 February2020