Mackie DLM12S - Smart Protect; Limiting; Overexcursion Protection; Thermal Protection

Owner’s Manual
13
Owner’s Manual
Smart Protect
ThereareadvancedDSPprotectionmechanisms
designedintotheDLM12Stosafeguardthesubwoofers
andampliersfrominadvertentdamage.
Theprotectioncircuitsaredesignedto
protectthesubwoofersunderreasonable
andsensibleconditions.Shouldyouchoose
toignorethewarningsigns[e.g.excessivedistortion],
youcanstilldamagethespeakerintheDLM12Sby
overdrivingitpastthepointofamplierclipping. 
Suchdamageisbeyondthescopeofthewarranty.
Limiting
Thedriverhasitsowncompressioncircuitwhich
helpsprotectitfromdamagingtransientpeaks. 
Thecompressorisdesignedtobetransparentand
isnotnoticeableundernormaloperatingconditions.
ThefrontLEDwillpulsewheninlimit.Turnthe
volumedown!
Overexcursion Protection
A36dB/octavehigh-passlterat32Hzjustprior
tothelow-frequencyamplierpreventsverylow 
frequenciesfrombeingamplied.Excessive
low-frequencyenergybelow29Hzcandamagethe
wooferbycausingitto“bottomout,”alsoknowas
overexcursion,whichisequivalenttoamechanical
formofclipping.
Thermal Protection
Allampliersproduceheat.TheDLM12Sisdesigned
tobeefcientbothelectricallyandthermally.
Theampliermodulehasinternalheatsinksand
adigitallycontrolledvariablespeedfan.AstheDSP
recognizesvaryinginternalheatlevels,itwillturn
onatanappropriatespeedtodrawcoolairinover
theamplierandexitviathesidevents.
Intheunlikelyeventoftheamplieroverheating,
abuilt-inthermalswitchwillactivate,mutingthe
signalandrampingthefanuptotopspeed.Anerror
messagewillalsoappearontheOLEDDisplay.
Whentheamplierhascooleddowntoasafe
operatingtemperature,thethermalswitchresetsitself,
andtheDLM12Ssubwooferresumesnormaloperation.
Ifthethermalswitchactivates,tryturningdownthe
levelcontrolanotchortwoonthemixingconsole(or
thebackofthesubwoofer)toavoidoverheatingthe
amplier.Beawarethatdirectsunlightand/orhotstage
lightsmaybetheculpritofanamplieroverheating.
FYI
TheFYIscreendisplaysthelatestUIversion,DSP
version,AmpB+[voltage]andcurrenttemperature.
Nothingmaybechangedorupdatedhere,justanFYI,
asstated.Thisscreenisdisplayedwhenpressingthe
VOL[10]andMEMbuttons[14]simultaneously.
AC Power
BesuretheDLM12Ssubwooferispluggedintoan
outletthatisabletosupplythecorrectvoltagespecied
foryourmodel.Itwillcontinuetooperateatlower
voltages,butwillnotreachfullpower.
Besuretheelectricalservicecansupplyenough
amperageforallthecomponentsconnectedtoit.
Werecommendthatastiff(robust)supplyofAC
powerbeusedbecausetheampliersplacehigh 
currentdemandsontheACline.Themorepowerthatis
availableontheline,thelouderthespeakerswillplay
andthemorepeakoutputpowerwillbeavailablefora
cleaner,punchierbass.Asuspectedproblemof“poor
bassperformance”isoftencausedbyaweakACsupply
totheampliers.
Beawareofanyerrormessagesthatmaybedisplayed
ontheOLEDDisplay.Overvoltage,forexample.
Neverremovethegroundpinonthepower
cordoranyothercomponentoftheDLM12S
subwoofer.Thisisverydangerous.