I had a question about noise in the stereo. I have two 12' subs hooked up to a 1200 watt amp. That is then hooked up to the back speakers with an audio rca adaptor. I recently pulled them out for more trunk space on a trip then later i put them back. Now every 20 to 30 seconds the subs make a loud noise. It doesn't all of a sudden become loud it instead works up to the loudest point. The music gets louderer with no real distortion except that it makes a "wha" sound in the background. You can still hear the songs but it's annoying. I've already checked the fuses. any other ideas?