i traded my friend amps awhile back...i gave him my power 800a2 and he gave me his mtx amp...i've noticed w/ the mtx amp that on silent parts in songs if i have the back seats folded down, it makes this semi-loud humming sound...my fosgate didn't do that...i've had 4 other fosgate amps and they didn't do that and i had 1 kenwood and it didn't do that...any ideas? its all wired up properly...is this a common problem w/ mtx amps or should i talk to mtx about it?

 

Maybe it's bored? Or, it doesn't know the words.
It could just be the power supply is noisy.

 

Some amps are more prone to line noise than others. A buddy of mine had a Sony Xplod amp that had engine noise like nuts, and when he put a new amp in, it disapeared. Some MTX amps aren't that great. Is it a Blue Thunder MTX? Those are better than the road thunder and thunder amps I believe.