Dolby Laboratories DP570 A.3.5 Generating Test Noise, A.3.6 Increasing the System Volume

68 Dolby® DP570 Multichannel Audio Tool User’s Manual
Configuring a Monitor System Calibrating Speaker Playback Levels
•Formusicmixing,eachspeakerchannelshouldbesettothesameSPL(thesameas
televisionmixing).Thereisnostandardpracticeforreferencelevelsformusicmixing.
Someengineersprefertomixlouderthanothersdo,butifthelevelsbetweenchannels
arecorrect,theoveralllevelisnotasimportant.
Whenmixingfortelevisionormusicinsmallmixingroomssuchasremoterecording
trucks,theSurroundchannelisgenerallyset2dBlowerthanthefrontchannels.Thistakes
intoaccounttheshortdistancetotheSurroundspeakers.Experiencehasshownthatthis
settingmakesthesoundinthehomeenvironmentveryclosetothesoundheardbythe
mixer.
A.3.5 Generating Test Noise
TheDP570generatestwokindsoftestnoise:pinkandfiltered.Pinknoiseexertsanequal
soundpressurelevelacrosstheentirespectrum.Filterednoiseispinknoisethathasbeen
highpassfilteredatthepreestablishedLFEcrossoverfrequency.
Clickabuttontogeneratetheappropriatekindoftestnoise.ClickPinkifyourbass
managementsettingisNone.Otherwise,clickFiltered.Thetestnoisebuttonsareshown
inFigureA‐2directlyundertheAnalogOutputscheckbox.
Whenactivated,thetestnoisecyclesaroundthespeakersinorder:Left,Center,Right,
RightSurround,BackSurroundRight,BackSurroundLeft,LeftSurround,andSubwoofer
—remainingtwosecondsateachoutputbeforemovingontothenext.
Thetestnoisefeatureisintelligent.Whenyoubeginanindividualspeakertrimadjustment,
thetestnoiseremainsatthatspeakeruntilyoucompletetheadjustmentandmoveto
anotherspeaker,allowingyoutoadjusttheSPLaccordingtothefollowingprocedure.
A.3.6 Increasing the System Volume
Afterturningonthenoise,raisethemasterVolu mesliderslowlyuntilmeterreadings
reachyourtargetSPL.Whenthesystemisproperlycalibrated,thistargetSPLwillregister
0onthemaster Volu mescale.Ifitdoesnot,adjusttheMa sterTrimslideruntilthetarget
SPLmeasures0onthemaster Volu meslider.Yo uarenowreadytobeginmakingfine
adjustments.
Warni ng:Beforeyouturnontestnoise,besurethatyourplaybacksystemissetnohigher
thanmoderatevolume.Iftheplaybacklevelishigh,youriskdamagingyour
speakersandpossiblyyourhearing.ThedefaulttestnoiselevelfromtheDP570
is–20dBFStothedigitaloutputs(+4dButotheanalogmonitoroutputs).