Audio Systems: car audio system problems, sony xplod, split charge

Question
i have had my system for about 3 months now and i biult it myself, (head unit: indash jensen, 2 sony xplod 1000watt each amps, 2 10 inch audiobahn peak 1000watt subs and 1 4-farad capacitor. each sub is powered by a seperate amp so they dont share power. my problem is that recently for some reason theyve lost power in the sound. wen both subs are playing, they sound muffled and strianed and it sounds like they are only putting out 10% power each. but wen i unplug one of my amps so that only 1 sub plays, the sound that one sub puts out is alot stronger but its still only like 40% of the power it was putting out before and wen i turn up the volume, the sub flaps distortedly like its being maxed out, but i no it would never max out at where its maxing out at. is there sumthing wrong with the way its wired up? or is sumthing wrong with my headunit, amps or subs??

Answer
Hi CJ
Forget the head unit.
Forget the subs,
I don't think it's the amps.
Looks like you have a power problem. With those size amps it calls for at least one (pref two)remote 100amh hour battery (pref, spiral) and a split charge relay.
Wire with heavy cable direct from battery live with the fuse no more that 2" from the battery termainal, Ground as close as possible to the amps with same weight cabel to a clean, bare, chassis point. all should be good.
Peter