So i have a 02 sport trac and got the mtx thunderform under the seat. Have a 4500 mtx sub in it with a mtx amp. Gains barely over half way up. Just recently it started making popping noises like its getting static in the lines, sometimes small and sometimes enough to make the sub hit pretty hard. Doesnt always do it, it does it randomly.. I checked connections and all are tight. I have it grounded to one of the bolts holding the seat down and also sanded off all the paint around the bolt. Possibly the amp going bad? Or possible RCA wire going bad? I have power wires and rcas on opposite side of the vehicle and do not cross at all. It has me stumped..Any ideas???