6. Polarity checking
Alltransformerprimariesshouldbeconnectedinparalleltotheoutputoftheamplier.Thesummedtotal
powerratinginwattsoftheselectedtapsettingsforallconnectedloudspeakersmustnotexceedthetotal
outputpowerratingoftheconnectedamplieroutputchannelinwatts.Itisrecommendedthatagenerous
powersafetymargin(minimum3dBheadroom)bemaintainedbetweenthetotalloudspeakerpower
requirementsandtheamplieroutputcapacitytoavoidcontinuousamplieroperationatfullratedoutput.
5.4 Wiring for EN54 and outdoor applications
ArightangledwatertightcableglandissuppliedwiththeVLS7and15foruseinoutdoorapplications(Fig.1).
TheVLS30hasaninputpanelcoverwithrubberwiringgrommetforuseinoutdoorapplications(Fig.2).
Beforemakingconnections,passthewire(s)throughthecablegrand/rubbergrommet.Theinputpanelcoveris
securedtothecabinetusingthefourscrewsalreadyinsertedaroundtheinput.
Fig.1 VLS 7 & VLS 15 Fig.2 VLS 30
6. Polarity checking
Checkingthepolarityofthewiringbeforethespeakersystemismountedorownwillhelpensuresatisfactory
performance.Ifyoudonothaveapulse-basedpolaritychecker,youmaycheckLFunitsasfollows:Connect
twowirestothe+and-terminalsofaPP3(9V)battery.Applythewireconnectedtothepositive(+)terminal
ofthebatterytothespeakercablelegwhichyoubelievetobeconnectedthepositiveterminalofthespeaker
connector;likewiseconnectthenegative(-)terminalofthebatterytothenegativeterminalofthespeaker.If
youhavewireditcorrectly,theLFdriveunitwillmoveforward.Atthispoint,connectthepositive(+)speaker
leadtothe+terminalontheamplierandthenegative(-)leadtothe-terminalontheamplier.However,if
theLFdrivermovesbackwardswiththebatterytest,theinputconnectionsneedtobeinvertedbefore
connectingtheamplier.Ifproblemsareencountered,inspectthecablewiring.Notethatdifferentamplier
manufacturersmayutilisedifferentpincongurationsandpolarityconventions;ifyouareusingampliersfrom
morethanonemanufacturer,checkthepolarityattheampliersaswellasattheloudspeakers.