I just bought two kicker S15L7's which are powered by two alpine mrp-850's and im wondering whether to buy capacitors or to buy a new alt and battery? Could i just buy two 1000 watt capacitors, or should i get the audio battery?
Capacitors are like storage banks. When your system hits the hard stuff, the capacitors flatten out the voltage drop in the circuit and do this by storing up on low draw times.
If you supply your system with 12v and is able to maintain 12v on it's own, the capacitor may help some, but if your system's voltage drops because you don't have enough charging capacity to keep up with the draw, the capacitor will not do anything for you.
I would upgrade battery or add a second and check to see what your alt output is. Don't forget an isolator, no matter how many batteries you have, not being able to start your car sucks.
That may not be the best explanation of a cap, but someone else will probably come up with something better.
If your car lacks power, then upgrade the big 3, HO alternator. Battery and caps are optional. Go to bcae1.com and read. Caps on only as good as it's usage. Nothing electronic is useless.
"And no, there is no substitute for the HO alt, and the battery won't help without it. I just know someone will ask that."
WRONG.If you have a huge batt bank you can run for a long while until you have to worry.When you park it in the garage just make sure to hook your bank up to a charger of some sort.There's quite a few guys running 18volt or 16 volt systems that do this in their daily drivers.Is it practical?No.Can it be done?Yes,and it has and is being done.That's like saying the cell phone battery in your phone is useless without it's charger,that is true but only partially.The battery in any system is good when it is charged up.An uncharged battery is pretty useless though.That's the point M.S. was making,once your alternator can't produce enough juice for the batts the batts drain until there's no reserve left and then they are useless.