sound system makes it stall(matt BC?)

[ian]

right have a young lad round here,say young he`s just past his test and has a 2.0 gl,
its on 19`s lowerd and looks really nice as he hasnt added any nasty spoilers etc,just kept the orignal calrotn shape,
any how his sound system is sometihng else, he has spent mega mega bucks on this car.
without being up on sounds system,it has a power cap??? fitted,
4 15inch subs 2 12 inch and 4 10 inch subs,surround by countless 6x9 and smaller speakers,
it does make a rumble,however when he turns it up anything above 1/4 the charge drops to 8.2v and eventerly the engine will stall(no 12v to the engine/feul pump)
when the radio is at a normal level/off and all lights heater rear w8indoware on  etc it will charge at 13.2v with all eletrics off at 14.6v
so to me that alternator is ok,
so the question is where can he source a much bigger alternator for a 2.0~?

[bigjohn1969]

batteries required,its ok fitting a power cap but that is only there for the bass amps to suck large amounts of power very quickly.
batteries cant suppy power as quick as a power cap.
when i did my last big install my car died when ticking over,so i had put in 3 600amp batteries, 1 in the engine bay and then 2 in the spare wheel well,combined with the 3 1 farad power caps this setup then didnt drop below 12 volt when running.
of course i should have done the alternator but it didnt seem necessary at the time.
then again you can put a battery in the boot and get a split charge system that leaves the engines power supply alone.

bigjohn

[A3LTR]

He could try fitting a split charger and a deep cycle battery, like whats used on.. dare I say... a caravan... these allow slow draining of the battery.. hook up the sound system to the deep cycle battery and the car electrics should be oK..