Mackie Thump12 - Protection Circuitry and AC Power; Limiting and Overexcursion Protection; Thermal Protection Mechanism; Power Supply and Amperage

Thump12 • Thump15 Powered Loudspeakers
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Thump12 • Thump15 Powered Loudspeakers
Protection Circuitry
Thumploudspeakersemployabuilt-inlimiterfor
lessdistortionatpeaklevels.Adynamicbassresponse
circuitprovidesoptimallowfrequencyresponse
regardlessofoveralloutputlevel.Additionalprotection
includesautomaticthermalshutdownshouldtheamp
overheat.However,withClass-Damptechnology,which
ishighly-efcient,thisshouldneverbeaproblem.
Theprotectioncircuitsaredesignedto
protecttheloudspeakers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loudspeaker
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
Asubsonicltercircuitjustpriortothepowerampli-
erpreventsultra-lowfrequenciesfrombeingamplied.
Excessivelow-frequencyenergycandamagethewoofer
bycausingitto“bottomout,”alsoknowasoverexcur-
sion,whichisequivalenttoamechanicalformofclip-
ping.
Thermal Protection
Allampliersproduceheat.Thumploudspeakers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Thumploudspeaker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loudspeaker)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Thumploudspeaker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Thump
loudspeaker.Thisisverydangerous.