So I've noticed lately that every time I go over a bump in the road my subs start this hissing buzz noise. Sometimes when it does it I'll poke at the off button for the head unit and that makes it stop sometimes, but now not even that is working and I have to turn the unit off completely and it still does it 5 minutes later. Any idea what I can do to fix this? I have 2 10" shallow Kenwood subs 6 speakers and a 2000 watt amp.