I have an old California Customs amp, 200w, running to an Infinity 12" sub. The HU is a factory with 4 disc changer. The amp was professionally installed. The amp turns on and stays on at all times. There is almost no sound out of my sub, besides some nasty bass every now and then when I hit a bump, and it's not the normal sound by any means. All fuses are tip-top. The installer had to run an RCA adapter piece attatched to the rear speakers in order to set up the RCA. That runs to my amp, and the speaker wires to my sub. I have never had any problems with this system before, and some of my more experienced friends are unsure about this one. Any thoughts?