2002 Sebring lxi 2-door coupe infinity sound problem

Hello,
 
I recently was driving down the highway in my 2002 Sebring lxi 2-door coupe which has the infinity premium sound system. Anyway, I was just listening to the radio at regular lower volume and all of a suddon I hear a crackling thud noise come out the back(presumably speakers) of the car and after that, no sound coming out of any of the speakers on the radio, cd, cassette, whatever. I can put a CD in the player and it is ticking off time like it is playing a song, but no sound at all. Same with the radio, can change channels, etc. but never any sound.
 
So, it seems like the CD/radio/tape deck is working fine, just no sound is coming out. Any ideas where I can begin to troubleshoot this issue? I've read to check the amp since that could be the problem but have read it could be under the passanger seat, or maybe the back seat? Any idea where the amp really is on this car? Once again, this is a 2002 Sebring lxi 2-door coupe(hard top) with the infinity premium sound system. Thanks alot to everyone for any suggestions!
 
m-man

I have a 95 Sebring LXI and the Infinity amp in it is mounted in the trunk under the upper deck... good luck