I just noticed this weekend that it seems like there is a bad ground connection somewhere with my amped rear 6x9's. You know the whine that changes pitch when you press the gas. It just started happening this weekend, nothing has been changed and the system has been working fine until now. I have noticed that it has started to get worst over time as well. I have checked all the connections on the amp, car, and speakers. Everything is nice and tight. Could my amp possibly have a bad internal connection? What else might be causing the problem?