My left channel cuts in and out (not completely on and off, but less than half the volume of the right.) I notice it mainly when excelerating hard or hitting bumps mid corner. It used to be every now and then, but now much more often. It is very annoying to have the speakers closest to my ears cutting in and out where they can hardly be heard. I had a car stereo dealer install a speaker to line level converter to the factory head unit (to run a sub), so I'm wondering if that's the problem. If any of you have had similar problems I'd really like to know.