I have a 2003 A4 Convertible. I'm going to add 2 10" subs to the factory deck to fill in the low end a little more. I have the Bose system, so I believe it uses an external amp. I would splice into the factory wiring to hook up the amp and subs. Can someone verrify the outputs on the deck are un amped. and if the crossover is in the amp?

Also, seems the front speakers are 3 way. tweets in the door, mids in the dash, bass in the doors. But when I fade the sound full front I loose all bass. When I fade full rear I lose all bass. Does anyone know why and how the car is wired to cause that?

Here is my next question. Would there be any advantage to hooking up an EQ to the whole system? would I get much of a benefit to that, or not?