I recently upgraded my system while keeping the stock head unit. I used an Audio Control LC7 Line level controller along with a JL audio 4 channel amp for front an rear mids and highs. I also added a Precision Power amp along with a 12" Alpine Type R sub. I realize that an aftermarket head unit will sound better than the stock, but I'm very disappointed with the result. The Highs are overbearingly "screatchy" and there just seems to be no midbass. i'm a long time car audio enthusiasts, so I do know what I'm doing. What I'm wondering is should I have maybe went with a different audio control device that offers eq capability? Also, does the rear speaker outputs put out a lesser quality signal then the front like I've read of some cars?? Thanks if anybody has any answers.