hello all i am new to the site and not sure if this is where i can ask this. if im in the wrong place let me know. well im helping my roomate out with his system he has a 03 jeep grand cherokee with a pioneer 6.5" indash hu not sure what model it is with a crossfire cfa-602 amplifier which is a 300x2 pushing a 15" jl w3 in a sealed probox. the woofer started making a weird humming noise constantly after it had been working fine for about 5 months. ive tried changing rca's and the noise was stillt there. i grounded the amp to a bolt under the back seats. im pretty sure its not the groud since when i first installed it it worked fine. what should i try? thanks in advance. this is a great site ill post pics of my system later when i get some pics!