So this is my set-up
2005 Grandprix with a Kenwood ddin, Crystal door speakers with no amp to them yet, Infinity 6 x 9"s in the rear on a small Alpine amp, 2 x 12" RD Audio subwoofers powered by a Kole 7000.1, It will push 4000 rms at 14.4v. I've got 4 gauge to the amp with a 6 farad capacitor, 0 gauge ground.
I'm having a power problem, the capacitor reads less then 10v when big bass hits. I don't want that to happen.
Give me some ideas please, i'm probably going to go with the cheapest option but would still like to hear them all

 

High output alternator and the "big 3" upgrade(google It if not in the know)

Extra battery would prolly be ur easiest/cheapest fix but not familiar with them.....yet.

 

an Extra battery did the trick

 

what'd u use?

 

i had an extra battery from my old boat, its cheap but it seems to be working fine, i wired it right in front of the capacitor and now it doesn't go below 12v while the cars running. my subs can handle more than what they're getting though

 

I would say you biggest power problem is trying to run 4000rms through a tiny 4ga wire. I would replace that with at least 0ga. Adding the extra batt is just a bandaid. Once it drains the 4ga is not going to be big enough to charge it quickly enough and you will be back to having issues until it manages to suck enough juice through that little wire to recharge. I was only running 2500rms in my Cavalier through 0ga and still had some voltage issues.

 

Ya, I've got the 0/1 gauge in, big 3, batt, cap, all made a big difference.