Dolby Laboratories DP570 A.3.2 Setting the Master Trim, A.3.3 Setting the Master Volume, A.3.4 Picking a Target SPL

Calibrating Speaker Playback Levels
Dolby® DP570 Multichannel Audio Tool User’s Manual 65
FigureA‐7
Figure A-7 Digital Reference Level
A.3.2 Setting the Master Trim
SettheMasterTrimshowninFigure 4‐10to0.
A.3.3 Setting the Master Volume
Beforegeneratingtestnoise,makesurethatmasterVolum eissetlow:–20to–30.Usethe
slidershowninFigure 4‐11.
A.3.4 Picking a Target SPL
WhenpickingatargetSPL,itismostimportantthateachofthemainchannelsissettothe
samelevel;theabsolutelevelissecondary.Thefollowingexamplesaresuggestionsfor
selectinganabsolutelevel:
•Forfilmwork,testnoiseatreferencelevelinthemainchannels(Left,Right,Center)
shouldproduceanSPLof85dBc.Forfilmwork,surroundchannelsarecalibratedto
anSPLof82dBcwithSurround3dBAttenuationchecked.ThenetresultisanSPLof
85dBcwhennoiseisplayedthroughthesystem.
•Fortelevisionwork,testnoiseatreferencelevelistypicallysettoproduceanSPL
rangingfrom79to82dBcforeachofthemainfivechannels.Thelowerreferencelevel
fortelevisionisduetotheloweraveragelisteninglevelsusedbytheconsumer
(typically70to75dBc).
•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,surroundchannelsare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.
Tip: TomakethisadjustmentyoumustclosetheSetupwindowtoactivatethemain
applicationscreen.Whensatisfied,reopentheSetupwindow.