Audio Systems: power loss, lead acid battery, watts rms

Question
I have a 2002 subaru wrx, i have recently installed 2 sony explode
10" 1100w peak subwoofers with a sony explode 1200w amp. the
amp is draining my battery when my car is at idle but seems to me
ok when i am moving. i was wondering do you think a capacitor
would work, and if so what size, or would i need a high-output
alternator & battery?

Answer
Yes, and yes.

If it is tugging the system down at idle, you probably need at least:

A higher output alternator.
Get one that will supply ALL of the vehicle current needs AND the entire demands of the Audio system, simultaneously.

A custom (smaller) pully on that new alternator (if not so equipped) so that the charging system will put out rated current at (or near) idle.
If you plan to sit at idle for extended periods, you'll really need the pully to be small enough to provide full output at idle. *If it is too small, you can wear out the alternator and its' bearings very quicky.

If using a normal Lead Acid battery:
Install 1 Farad of capacitance for each 1000 watts RMS, if you plan to use the battery(s) only for extended periods.
This will help the instant current demands which the battery cannot provide by itself.


It is very easy to install more Audio Power than a given vehicle can provide.
The power supply needs beefed. You will then be very happy with the Charging System performance. The audio system can soon follow. ;)


Sincerely,
Jerry Mael