Gavin's right there guys. Look through the previous posts here and elsewhere for this debate. All a cap is to your system is a band-aid for other problems. You're better off with a higher output alternator. Buy the cap if you want to but know that it's not going to actually fix any of your electrical issues.
Okay, don't believe me. Get a cap and will it to work. You guys do understand if there is enough strain on your electrical system, that means you need a better alternator and a better battery. A cap is not the answer. It's all marketing BS. Please show me proof that a cap is beneficial to your system and then I'll take back what I said.
I may not know a whole lot about car audio, but I do know enough that in my next system, I will not have a cap.
Loudnissan is right. A capacitor will help you with very minor electrical problems, such as your dome light slightly dimming and maybe even some slight headlight dimming depending on the size of the cap.
A cap in NO WAY will be the difference between your car starting or not. For the most part, a capacitor is just for show, and the one's with the display are a pretty easy way to keep tabs on your system voltage without buying a dakota digital monitor or something like that (which usually costs as much as a digital cap).
Bottom line is that a cap is definitely more show and less go, but to say caps are completely useless isn't true either. They solve minor problems. But then again, chances are that if you're having minor problems now that they'll turn into major problems (i.e. - dead alternator) before too long. I say forget about the cap and put the money you would use into a fund for a new alt when the time comes.
yo screw caps they r a waste of money, for the price of a good cap(200$) you can get a way better pumped up alternator for 130 from jc whitney.alty alternators push out 60 amps for any sysytem over 1000 watts you should have at least 120 amps.caps are only good for bass.you should invest in good wires,battery terminals and a new alternator