Mackie SRM1850 - Smart Protect Features; Limiting and Overexcursion Protection; Thermal and AC Power Management

SRM1850 • SRM2850 Powered Subwoofers
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SRM1850 • SRM2850 Powered Subwoofers
Smart Protect
ThereareadvancedDSPprotectionmechanisms
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subwoofer
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.
Overexcursion Protection
TheSRM1850hasa24dB/octavehigh-passlter
at30Hz,whiletheSRM2850hasa24dB/octave
high-passlterat32Hzjustpriortothelow-frequency
amplier.Thispreventsverylowfrequenciesfrombeing
amplied.Excessivelow-frequencyenergy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.SRMsubwoofersare
designedtobeefcientbothelectricallyandthermally.
Intheunlikelyeventoftheamplieroverheating,
abuilt-inthermalswitchwillactivate,mutingthe
signal.
Whentheamplierhascooleddowntoasafe
operatingtemperature,thethermalswitchresets
itself,andthe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.
AC Power
Besurethe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.
Neverremovethegroundpinonthepower
cordoranyothercomponentoftheSRM
subwoofer.Thisisverydangerous.
Care and Maintenance
SRMsubwooferswillprovidemanyyearsofreliable
serviceifyoufollowtheseguidelines:
• Avoidexposingthesubwooferstomoisture.
Iftheyaresetupoutdoors,besuretheyare
undercoverifrainisexpected.
• Avoidexposuretoextremecold(below
freezingtemperatures).Ifyoumustoperate
thesubwoofersinacoldenvironment,warm
upthevoicecoilsslowlybysendingalow-level
signalthroughthemforabout15minutesprior
tohigh-poweroperation.
• Useadryclothtocleanthecabinets.Onlydo
thiswhenthepoweristurnedoff.Avoidgetting
moistureintoanyoftheopeningsofthe
cabinet,particularlywherethedriversare
located.