I have a major problem. I have a Pioneer avid d2 nav-unit and a kicker zx700.5 5 channel amp. everything is installed but all 4speakers and sub is only working from one set of rca's. when the front and rear rca's are installed in the amp i hear nothing but faint bass from the subs. but when i only use the front or the rear seperately all 5 speakers play. what in the hell do i do? and i do not have any fade.