I have a 91 type 4 cd player with the AE system and the subwoofers in the door with passive belt amplifyer (that just means the amp is under the dash) and I want to keep the stock head unit but I want good solid bass not crazy bass and I want quality sound. So there has to be some of you out there that has done this without changing out the head unit and I would like to hear your set up. THANKS