I have two 15" L7's with a PPI DCX 1500.1. Right now i have a 5 farad capacitor but it doesn't seem to do dick. Ive already gone through one alternator and my new one of about 5 months seems to be going down hill. When i'm pounding for more than like thirty seconds i start losing some of my bass ( and my highs, which are not connected to an amp, just my cd player)I will get the full bass and highs back when i restart my car but they dont last long. Is my alternator not producing enough power or could it be something else? I'm looking for the best solution to keep my alternator in good shape and still be able to run my speakers at their full potential. Sorry for the long thread. Any advice to my problems will be greatly appretiated. Thank you.