strange problem with infinity gold in GC

I have a `99 GC with the infinity gold system with 6 speakers for a few months now. A couple of weeks ago I noticed that the front 4 speakers got real quiet and I had to turn the fader control way up to hear the front speakers, the back 2 sound fine. Sounds really crappy now. I could see if it was the left or right channel but front to back? Doesn`t make any sense to me. Maybe something in the amp under the rear seat? Does it have some kind of wierd fuse setup somewhere I didn`t see?

front speakers on gc going out is not uncommon,but i think it might be the two small speakers in the dash plate that have gone bad,they are very weak.
Check with jeep dealer for replacements.They are very easy to change and to make your system sound proper they are a must.cdc

Don`t think that`s it. All 4 front speakers got very soft at the same time. Any ideas?