I have a JL 500/1 with 2 JL 12W3V2 subs. What do i need to do in order to keep my volt meter from dropping so much on big bass hits. I have heard a cap will help but i want to fix the problem. I am running 4 gauge power and ground and 12 gauge speaker wire.

 

A Cap will help, it may not fix the problem; an upgraded alternator should help it the most. A 1 Farad cap should be all you need.