Dolby Laboratories DP570 A.3 Calibrating Speaker Playback Levels

Configuring a Monitor System Calibrating Speaker Playback Levels
Dolby® DP570 Multichannel Audio Tool User’s Manual 67
A.3 Calibrating Speaker Playback Levels
Thefollowingsectionsdiscussandillustratethestepsinspeakercalibrationintheorder
theyshouldbeperformed.Normallythisentireprocessneedonlybeexecutedoncefor
eachsetofmonitorspeakers.Wedorecommendperiodiccheckstoverifythatcurrent
settingsarestillappropriate.
A.3.1 Setting the Digital Reference Level
Setthisleveltomatchyourstudioʹsdigitalreferencelevelbeforeturningonatestnoise
whencalibratingyourspeakersystem.
Thedefaultvalueis–20dB.Adjustitusingthedialshownin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).
Tip:TomakethisadjustmentyoumustclosetheSe tupwindowtoactivatethemain
applicationscreen.Whensatisfied,reopentheSetupwindow.