I have a 2002 Audi A4 and i was wanting to put in a box with 2 12" subs and a 1000-1200 watt amp...is that possible with the stock Audi sound system? I have the symphony sound system

 

it depends on wheter or not the head unit has RCA outputs on the back, the easiest way to determine this is to pop it out of the dash and youll literaly see a white and red RCA plug.

I wouldt recommend installing subs on the stock head unit though. Stock head units, while some have Line out for subs, have no control over the subs, and the Equalizer doesnt effect the sound they output.

Id recommend replacing the stock head unit, its not hard at all to do and the wiring i a breaze. if you plan to do this, its as simple as connecting wires. Id reccomend going to either crutchfield, or circuit city and getting a wireharness. It adapts into your stock system so you just slide the aftermaket wires right into the clearly labled slots.

If you need additional help on install, i can help you.

 

If you want to keep your stock deck then get a high/low level converter and tap into the rear speaker which is alot cheaper than getting the wire harness and a new deck.

 

NONSENSE! Your Bose Symphony system puts out low level (and, the head unit is widely regarded as one of the best, it has the flattest output) to the Bose AMP in your trunk, tap into your woofer low-level + and - and get your 5v turn on all in one place. I have 2 12" Boston Acoustics G512s hooked up now, I am in the process of finding a dealer so I can get a 1200W GT-28 to power them. MAKE SURE YOU HAVE A CAPACITOR!!! 1 farad for every 500 watts. At the moment I have a crappy Pioneer 800 watt amp.

Search around here, or when I head home I'll upload the wire diagram I used.

It looks, works, and sounds great. It puts out something like 3.5ish volts, so make sure your amp can adjust. Combine that with the bass-boost on amp, and it *MORE* than makes up for the lack of "independent" control in the head unit.