i have 4 10inch kicker comp cvr and a hifonics 1200 2channel amp everythings wired correctly just re wired it and it still does it.... the subs will work when i crank the bass knob and everything but once i turn the volume up to around 30 they stop working and just start making a vibarating noise like verrrrrrrrrrrrrrrrrrrrrrverrrrrrrrrrverrrrrrr not that loud but they deffintly arent slamming like before. also i have already grounded the rca's on the hu once before and thinking this was the problem i re grounded them and it still does it and yes i have a pioneer hu any suggestions please please please