Contour Enthusiasts Group Archives Forums Modifications Audio Found out I have a factory amp. Now what?

Line noise. You will amplify all the noise produced from one amp into the next amp. It isn't a clean way to do it, not to mention that most amps have low level inputs. You would need something to attenuate the output of the factory amp, or buy an amp with high level inputs. Usually only low-end amplifiers have high level inputs, they don't put them on high end stuff because they aren't very clean anyway.

The actual speaker wires come out of the factory amp and go straigh to the door speakers. If you are using he factory deck you want to take the line level outputs (small four wire square plug IIRC) and feed them into your amp and then run the amp direct to your speakers.