NHT A-10 User manual

Copyright2001NHTPro,aRecotonCorporationBrand
A-10
OwnersManual
A-10LeftMonitorSerialNumber:
A-10RightMonitorSerialNumber:
A-10ControlAmplifierSerialNumber:

CAUTION
RISKOFELECTRICSHOCK
DONOTOPEN
WARNING:SHOCKHAZARD-DONOTOPEN.
AVIS:RISQUEDUCHOCELECTRONIQUE-
NEPASOUVRIR.
SafetyInstructions--PleaseReadFirst
DETAILEDSAFETYINSTRUCTIONS:
Allthesafetyandoperationinstructionsshouldbereadbeforetheapplianceisoperated.
RetainInstructions:
Thesafetyandoperatinginstructionsshouldberetainedforfuturereference.
HeedWarnings:
Allwarningsontheapplianceandintheoperatinginstructionsshouldbeadheredto.
FollowInstructions:
Alloperationanduserinstructionsshouldbefollowed.
WaterandMoisture:
Theapplianceshouldnotbeusednearwater(e.g.nearabathtub,washbowl,kitchensink.laundrytub,inawetbasement,ornearaswimmingpool
etc.).
Ventilation:
Theapplianceshouldbesituatedsothatitslocationorpositiondoesnotinterferewithitsproperventilation.Forexample,theapplianceshould
notbesituatedonabed,sofa,rug,orsimilarsurfacethatmayblocktheventilationopenings,orplacedinabuilt-in installation,suchasabookcase
orcabinetthatmayimpedetheflowofairthroughtheventilationopenings.
Heat:
Theapplianceshouldbesituatedawayfromheatsourcessuchasradiators,heatregisters,stoves,orotherappliances(includingother
amplifiers)thatproduceheat.
PowerSource:
Theapplianceshouldonlybeconnectedtoapowersupplyofthetypedescribedintheoperatinginstructionsorasmarkedonthe
appliance.
GroundingandPolarization:
Precautionsshouldbetakensothatthegroundingorthepolarizationmeansoftheapplianceisnotdefeated.
PowerCordProtection:
Powersupplycordsshouldberoutedsothattheyarenotlikelytobewalkedonorpinchedbyitemsplaceduponoragainst them,paying
particularattentiontocordsandplugs,conveniencereceptaclesandthepointwheretheyexitfromtheappliance.
Cleaning:
Theapplianceshouldonlybecleanedasrecommendedbythemanufacturer.
Non-usePeriods:
Thepowercordoftheapplianceshouldbeunpluggedfromtheoutletwhenleftunusedforalongperiodoftime.
ObjectandLiquidEntry:
Careshouldbetakensothatobjectsdonotfallandliquidsarenotspilledintotheenclosurethroughopenings.
DamageRequiringService:
Theapplianceshouldbeservicedbyqualifiedservicepersonnelwhen;
Thepowersupplycordortheplughasbeendamaged;or
Objectshavefallen,orliquidhasbeenspilledintotheappliance;or
Theappliancehasbeenexposedtorain;or
Theappliancedoesnotappeartooperatenormallyorexhibits amarkedchangeinperformance;or
Theappliancehasbeendropped,ortheenclosuredamaged.
Servicing:
TheusershouldnotattempttoservicetheappliancebeyondwhatisdescribedintheOperatingInstructions.Allotherservicingshouldbe
referredtoqualifiedservicepersonnel.
CAUTION:Toreducetheriskofelectricshock,donotremovethe
cover(orback).Nouserserviceablepartsareinside;referservicingto
qualifiedpersonnel.
WARNING:Toreducetheriskoffireorelectricshock,donotexpose
thisappliancetorainormoisture.
Thissymbolwhereveritappears,alertsyoutothepresence
ofuninsulateddangerousvoltageinsidetheenclosurethat
maybesufficienttoconstituteariskofelectricshock.
Thissymbol,whereveritappearsalertsyouto
importantoperatingandmaintenanceinstructionsinthe
accompanyingliterature.Readthemanual.

RackRail
A-10
Amplifier
FrontPanel
Screws Insulating
Washers
Fig.1:RackMountingDetail
INTRODUCTION:
ThankyouforyourselectionoftheA-10.Yourstudiomonitorsareacriticalelementinthecountlessdecisions
madeduringrecording,mixing,masteringandotherkeyaspectsofaudioproduction.Theymustdelivera
transparent,neutralandrevealingassessmentofsound,sothatyouhavetheinformationyouneedtochooseand
placemicrophones,setEq’s,balancemixes...deliverexceptionalproduct.TheA-10iscapableofstate-of-the-art
sonicresolutionandflexibility.InvestingtimetolearnabouttheA-10’sfeaturesandoperationwillrewardyouwith
thebestpossibleperformance.
Ifyourequireassistanceatanytimeduringorafterthesetupprocess,callourCustomerServiceHotLineat1-800-
NHT-9993(648-9993).Youcanalsovisitourwebsiteatwww.nhtpro.comformoreindepthtechnicalinformation.
Thanksagainforyourconfidenceinourproducts!
GETTINGSTARTED:
TheA-10isauniquesystemthatcombinesadedicatedcontrolamplifierwithloudspeakermonitorcabinets,using
controlledimpedancecablesthatactuallyformpartofthecrossovernetwork.Bydesigningthesystemasanintegral
packageinthismanner,manyoftheadvantages ofself-poweredspeakerscanberealizedwithoutattendant
performancecompromise.However,itmustberecognizedthatthecontrolamp,cablesandmonitorsarean
inseparablepackage.
ThefollowingareincludedintheControlAmplifiercarton:
1ea.-ControlAmplifier2ea.-20'MonitorOutputCables
1ea.-6'IECPowerCord4ea.-10-32RackMountingScrews
1ea.-WarrantyRegistrationCard8ea.-PlasticInsulatingWashers
TheA-10MonitorsmustonlybeusedwiththeA-10ControlAmpandcables,andviceversa.
TheA-10ControlAmplifiermaybeusedonashelf,ormountedinastandard19”equipmentrackusingthe
screwsandwasherssupplied.Forrackmounting,removeandretainthefourfeetfromthebottomoftheamp
chassisusinga#2Philipsscrewdriver.Twoverticalrackspacesarerequired,butwerecommendyouleaveatleast
oneadditionalopenspaceaboveandbelowtheA-10forimprovedcooling,asyouwouldwithanyhighpower
amplifier.Fortableorshelfuse,thefourfeetmustremainattachedtoallowforaircirculation.Asastartingpoint
forspeakerplacement,alignthebackoftheenclosuresparalleltotherearwall,withtheangledfrontsfacingin
towardsyou.Formoredetailedspeakerplacementinformation,seepage7.
Fig.2TypicalSystemConfiguration
Signalflow
.
ToACLine
Signalflow
Signalflow
MonitorOutputCables
A-10 Control Amplifier
MPOWER
SENSITIVITY BOUNDARY POSITION
+11+4 -3-10 NFMF0
1

SYSTEMCONNECTIONS:
CONTROLAMPLIFIERINPUTSECTION:TheA-10ControlAmplifieracceptsbothbalancedand
unbalancedinputsoneitherXLRor1/4”TRSconnectors.Theseconnectorsarehardwiredinparallelwithinthe
A-10toallowforconvenientequipmentchaining,butonlyonesignalsourceshouldbephysicallyconnectedto
theunitatanytime.Figure3aindicatesproperwiringprotocolforeachtypeofconnector.Sincethereare
manydifferentconnectortypesandsignallevelsemployedbysourceequipment,someexperimentationmaybe
necessary,keepinginmindthatA-10canaccept awiderangeofsignalsandhasaninputsensitivitycontrolon
thefrontpanel.
SPEAKERCABLECONNECTIONS:TheA-10includestwo20’specialpurposecablestoconnecttheControl
unittotheMonitors.Whilethesecableslooksimilartostandardmicrophonecables,theyareconstructedwith
lowerandmoreconsistentconductorimpedance.PortionsoftheA-10’scrossovercircuitryarelocatedinboth
theamplifierandspeakerenclosures,andthecablessuppliedareanimportantpartofthiselectricalnetwork.
Thisallowsthespeakercablestofunctionasaneutralandtransparentcomponentinthesystem.Replacingor
extendingthesuppliedcableswithanyothertypewillhaveavarying,andonlypartlypredictableimpactonthe
soundoftheA-10.Ifyourinstallationrequirestheuseofalternativecables,youmayconsultthesuppliedtable
listingourmeasurementdataonavarietyofcabletypes.BesuretheyarewiredasshowninFig.3a.These
considerationsaside,usingthesuppliedNHTProcablestoconnectthecontrolamplifierisquitesimpleand
straightforward.Boththeamplifierandthemonitorsaremarkedwiththeappropriate“left”and“right”channels.
FittheXLRconnectorsintothecorrespondingconnectorsonthecontrolamplifierandmonitorsuntilthe
connectorlocks.
WARNING:IFUSINGCABLESOTHERTHANTHOSESUPPLIEDWITHTHISSYSTEM,BESURE
THATNOCONDUCTORISWIREDTOTHEXLRCASING.FAILURETODOSOMAY
CONSTITUTEARISKOFELECTRICSHOCK.
CAUTION:MAKEALLCONNECTIONSWITHTHEACPOWEROFF!
CAUTION:CONNECTINGTHEOUTPUTOFTHEA-10CONTROLAMPLIFIERTOANY
EQUIPMENTOTHERTHANTHEA-10MONITORMAYCAUSEEQUIPMENTDAMAGE.
Fig.3aBalancedWiringDiagram
1
2
3
+(SIGNAL)
-(GND) Shield
SOURCE A-10INPUT
Fig.3bUnbalancedWiringDiagram
NHTPro
MODELA-10MONITORPOWERMODULE.
SERIALNO:
NHTPro.
BENICIA,CALIFORNIA,U.S.A.
A10-A-10001
MADEINTAIWAN G1
A-10MONITOR
LEFT
CAUTION:
CONNECTINGOUTPUTSTOANY
PRODUCTOTHERTHANNHTPro
A-10MONITORMAYRESULTIN
SEVEREEQUIPMENTDAMAGE.
A-10MONITOR
RIGHT
FUSETYPE:
T5A250VFOR110/120V.
T3A250VFOR220/240V.
50/60Hz-600W
INPUTVOLTAGE
CAUTION
RISKOFELECTRICSHOCK
DONOTOPEN
WARNING:SHOCKHAZARD-DONOTOPEN.
AVIS:RISQUEDUCHOCELECTRONIQUE-
NEPASOUVRIR.
FORCONTINUEDPROTECTIONAGAINST
RISKOFFIREREPLACEONLYWITHSAME
TYPE250VFUSE.
CAUTION:
NHTisaregisteredtrademarkoftheRecotonCorporation.
Fig.4A-10ControlAmplifierRearPanel

USINGTHEA-10CONTROLFUNCTIONS:
TheA-10controlsaredesignedforutilityandrepeatabilityundervaryingconditions.Youshouldfindtheeffects
ofthecontrolssonicallysubtle,withlittleimpactonthebasiccharacterandaccuracyofthespeaker.We
encourageexperimentationtofinetunethesystemtotherequirementsofyourparticularinstallation.
POWERINDICATORS:JusttotheleftofthepowerswitchontheA-10ControlAmplifieraretwopower
relatedLED's.Theupper(green)LEDlightsupindicatingthereisACpowertotheamplifierandthePOWER
SWITCHisinthe“on”position.Thelower(red)LEDindicatesaclippingoroverloadcondition.Occasional
flashingofthisindicatorisagentlewarningyouarereachingthesystem’slimits.IftheredLEDglows
continually,severeclippingisoccurring.Theinputsignalorsystemgainshouldbereducedtoavoidtheriskof
possiblesystemdamage.
SENSITIVITY:Thiscontrolisusedtochangetheinputsensitivitywithsettingsat;-10dB,-3dB,+4dB,+11dB
and(M)uteprovidingnoisefree,consistentgainmatchingwithawidevarietyofequipment.Thepropersettingis
thelowestsensitivitypossible(highestdBnumber)whichallowsthespeakertoreachthemaximumdesired
outputwithoutsourceclipping.Professionaldevicestypicallyspecfulloutputat+4dB,mostconsumeraudio
productsreachfulloutputat-3dB,andmostcomputersoundcardshaveafullscaleoutputof-10dB.Consultthe
owner’smanualforthedeviceconnectedtotheControlAmplifierforitsoutputlevelspecificationsandsetthe
SENSITIVITYswitchaccordingly.
BOUNDARYCONTROL:Reflectiveboundaries,suchasfloors,walls,eventabletops,reinforceaspeaker’slow
frequencyoutput.Conversely,placingspeakersoutintoaroomdecreasesbassresponse.Thegreatestlow
frequencyoutputiswiththeBOUNDARYcontrolinthe“0”position,whichassumesnosignificantboundary
reinforcementispresent.Thecontrolattenuateslowfrequenciesby3dB(at50Hz),withrapidlydecreasing
effectabove300Hz.RefertothediagraminFig.6forinformationonsettingthecontrolappropriately.
0
1
0
1
Fig.6:BoundaryControlSettingsDiagram
HalfSpace
WholeSpace
A-10 Control
Amplifier
MPOWER
SENSITIVITY BOUNDARY POSITION
+11+4 -3-10 NFMF0
1
Fig.5A-10ControlAmplifierFrontPanel

POSITIONCONTROL:Closeinmonitoring,sometimesreferredtoas“near-field”reducestheeffectofroom
acousticsonthesignal,andprovidesgreatdetail.Mid-fieldlisteningrevealsaspectsofrecordedambienceandis
morerepresentativeofenduse.However,aspeaker’supperfrequencypowerresponsechangeswithdistance,due
toroominfluencesandairabsorption.TheA-10maybeadjustedforflatresponseattwolisteningdistances.
Themaximumhighfrequencyoutputisobtainedwiththecontrolinthe“FF”(far-field)position.Inthenear-
field,thecontrolattenuates20kHzby 2.5dB,withnoeffectonfrequenciesbelow3kHz.SeeFig.7forthe
appropriatePOSITIONcontrolsettingbasedonlisteningdistance.
SPEAKERPLACEMENT:
TheA-10isintendedtoprovideconsistentperformanceoverawiderangeofplacementsituations.Thisis
accomplishedthroughtheuseofelectricalcontrols,widedispersiondrivers,advancedenclosuredesignand
carefullychosencrossovercharacteristics.Nevertheless,itisalwaysworthinvestingtimeandeffortexperimenting
withoptimumloudspeakerplacement.Inallcases,A-10Monitorsshouldbesetupsymmetricallyequidistant
fromthelisteningposition;theleftspeakerandrightspeakershouldbeatthesamerelativepositionswithrespect
totheprimarylisteningarea.Thisisimportantinorderthehearaproperstereosoundstage.Thespeakerbaffles
angleintowardsthelisteningpositionwiththeloudspeakerbacksparalleltooneanother.Agoodstartingpoint
canbefoundinFigure8below.Ideally,thetweeterheightshouldbeonaxiswithyourears,orslightlyabove.
Also,rememberthatnearbyreflectivesurfacescanalterimpulseresponseandblurimagingandtonality.
POSITION
NF MF
POSITION
NF MF
Near-Field
Mid-Field
Listening
Distance
A-20
Monitor
A-10
Monitor
Fig.7PositionControlSettingsDiagram
<1M 2-3M
ListeningPosition
D
Fig.8IdealMonitorPlacement

SYSTEMOPERATION:
TheA-10iscapableofveryhighoutputlevels,especiallywhenlisteninginthenear-field.Still,everyspeaker
systemhasitslimits.Protectyourearsandusecommonsense.Harshbreakupatextremelyhighvolume,orheat
emanatingfromthedriversisanindicationthatthesystemhasexceededitsoutputlimitsandyoushouldlower
theplaybacklevel.Andwatchforexcessivelightingoftheamplifierfrontpanelclippingindicator.Speaker
damagemostoftenoccursfromsustainedhighvolumelevels,notfromtransientsoundsorbriefmusicalpeaks.
A-10STUDIOMONITORSYSTEMCARE:
Exceptfortheoccasionalflatteringcomment,yourA-10needsnoregularmaintenance.Neverattempttoclean
theA-10Monitordriverunitsexceptforverylightfeatherdusting.TheA-10MonitorcabinetandtheA-10
ControlAmplifierfrontpanelcanbecleanedusingadamp,softcottonclothfirstsprayedwithamild,
nonabrasiveglasscleaner.Neverspraythespeakeroramplifierdirectly!Avoidsiliconeoroilbasedcleanersor
treatments.
NEEDHELP?
TechnicalSupportcanbereachedseveralways:Telephoneustoll-freeat(800)-NHT-9993(648-9993),E-mailus
at:[e-mail],Faxusat:[phone]orwriteusat:NHTPro,527StoneRd.,Benicia,CA94510.Or
visitourwebsiteatwww.nhtpro.com.

SYSTEMSPECIFICATIONS:
Type:Modular,twopiecepowerednear/midfieldmonitor.
Configuration:2-wayacousticsuspension.
Woofer:6.5"treatedpaper.
Tweeter:1"softdome.
MagneticShielding:Full.
PERFORMANCESPECIFICATIONS:
AmplifierPower:150W(continuousRMS/ch),300W(100mspeak).
PeakAcousticOutput:116dBSPL(100mspinknoise@1M).
Residualhum/noise:<10dBSPL(Aweighted@1M).
THD@90dBSPL:<0.8%(100Hz~10kHz@1M).
SystemResponse+/2dB(1/3oct.sweptnoise):57Hz~20kHz@1M,55Hz~20kHz@2M.
-6dBLFcutoff:50Hz(inroomresponse).
LoudspeakerDimensions/Wgt.:11.9"hx7.5"wx10.7"d/14lbs.
LoudspeakerMaterials:0.75"MDFw/highpressurelaminate(internal+external).
ControlAmplifierDimensions/Wgt.:3.5"hx19"wx13.25"d/32lbs.
FEATURES/CONTROLS:
Connectors:
Input:XLR,TRS.
Outputtomonitor:XLR.
Controls:
Sensitivity:5position(-10dB,-3dB,+4dB,+11dB,Mute).
Wallproximity(Boundary):2position(0.0,1.0).
ListeningProximity(Position):2position(near/mid).
Power:On,off.
LEDDisplays(2):
Power.
Overload.
NHTPro
527StoneRd.
Benicia,CA94510
ph:[phone]
fx:[phone]
www.nhtpro.com