What battery would fit my car?

I have a 2005 Honda civic lx and I want a battery that is stronger than the one that I currently have in. The one that is in now is 500 CCA and I'm looking for one that is better then that. I want a new battery because I recently got a subwoofer and an amp and it is making my lights dim and my voltage drop from 14.2 to 13.0 when the bass hits. Also when my engine is off my amp goes into protection mode because it can't get enough power from my battery I believe.

We can only put in a slightly larger battery due to size limitations physically. We ca.n fit a heavy duty deep cycle type.

The world would love it if your battery was dead. We do not enjoy your musical taste. Of course, we know that will make you turn it up.

I also have a Honda my suggestion would be upgrade to a (optima batteries) worth the price. From experience running several aftermarket equipment in mine without dimming or power loss issues