4 15" CVR's would be even louder! Thats what I Have in the ext. cab of my 94 dodge dakota! It rocks the loudest thing I have heard around in a long time, I'm runnin 2# 1 farad caps, 2# optima batteries, and 2# kicker 1200.1 sub amps! Bass wise anyway! E mail me if you want to here bout the mids & highs!!!!!!!! Ha! Ha! Ha!