I think I figured it out. I'm gonna get one more 15, and really pound - 3 15's gotta hit harder than 4 12's. I'm just afraid that if I got the 4 12's that in 6 months I'd be making another thread asking if I should do 3 15's or 4 15's anyway, lol! Thx y'all. Now I just gotta figure out how I'm going to power it all. I'm already UNDERpowering the treos by 500w each. I don't wanna try to power all three with only 4000 watts (lol, "only").