Brennan Doehring

They're rated at 400W RMS, that Rockford is only pushing 500 (although I guarantee more; check birthsheet if it came with one), and you are having two. You'd need 800W to hit their rated RMS, and knowing Sundown you can probably double up on that and give them 1600W if you wanted to. 500W would work fine, but if you want the potential out of these guys, I'd give them at least 1000W.