geezer

What sort of amp should I be looking for to boost the volume just using the stock Concert head unit and the stock speakers in an A4?

(Sorry if this has question has been answered a zillion times already...)

ericu

works with the stock head unit. The head unit powers the front speakers but not the back speakers (separate amp located by the speakers). I tried to use a cheaper Alpine but it could not handle the differing line levels.

There are devices (www.soundgate.com) that can modify the high level output for the front speakers but I decided to go for the better amp vs. spending money on a corrective device.