Just thought that I had to post this.

It seems on every message board I go on, except car audio ones, people have misconceptions about a capacitor's function in the car's electrical/audio system. I'll attempt to clear this up.

First you have to understand how a battery works and how your alternator works to understand how a capacitor can be to your advantage.
When your car is on and running, basically your battery is in i guess you could say "standby" mode or charge mode. The alternator gets spun from the belt, etc etc, it creates current and recharges your battery. When you have your system pounding alot, there is alot of current draw from your battery. Your batteries chemicals mix and create current for your system to take to the amp where it can output it through your speakers. So right when the bass hits, your amp is drawing current from your battery and if you draw too much, your battery won't recharge fully or efficiently, and your alternator will have a strain on it.
This is where people think "oh a capacitor will solve all my problems".

This is incorrect.
The function of a capacitor is to store energy inside itself for those huge bass current draws so the strain is not instantaneously put on the battery right when the bass hits. But nonetheless, the cap will draw current from your battery ahead of time, and your alternator will STILL need to recharge it. It helps a little, but an analogy you can think of in this situation is pretty much like putting a band-aid on an open flesh wound.

But there is a solution!
Your alternator can only put out so many amps. It's basically designed to regenerate enough battery power to power your stock electrical system components. So when you have this huge strain from a big system, it can't really handle it.
Most stock alternators on hondas are around 80 amps or so, give or take. So when you have those 80 amps to run your electrical system in your car, thats fine it'll work great. But when you have an amp that has say, a 65 max amp current draw from your battery, you only have about half power going to your other electrical system components on average. This would explain your lights dimming when the bass hits.
But if you can get ahold of a high output alternator which puts out lets say 165 amps or so, you're set! Your amp can have MAX current draw which probably won't happen unless you're competing in an SPL competition and doing burps, so you're still left with 100 amps to power the rest of your electrical system; which (hypothetically) takes 80 amps. So you even have 20 extra amps left over. Everything has all the power it could ever want to run and then some. You could be driving around at night, with your lights on, your AC going and your system full blast, with absolutely no battery/eletrical system strain. No dimming, nothing.

So if you want to help out your battery or your eletrical system, think about an alternator FIRST, before a capacitor. You need the right tool for the job.

Hope this helps some people out. And if I have said anything wrong, just correct me. I'm still learning too :thumbup: