As of rite now, i have only 2 american bass xfl 15's. But i plan on going with four and a 500.1. I have the vfl150.1 rite now with the two and had four mids for my front stage and it couldn't keep up with just the 150.1. i had two 6.5's one in each door and two 5" one in each pillar. The sound amp was the sq945 4 channel, i had id bridged to each side. But like most i want to hear my sounds just as much as the bass, no more no less.......