I have 2 mtx 600 12's wired in parelle in a bandpass box for a 2ohm load powered by a kenwood class d mono block 1000 watt 1 ohm stable amp. It is running off the stock deck by using a high level to rca plug converter. My problem is that when i turn my car off the subs make an extremely loud couninuous thump until i put the key back in the ignition. If i turn my deck off before turning the car off there is no problem. Anyone have any ideas?