i have a powerbass 4k xta on a 12in xl with level 5 spider and it does just fine so i think you should be fine with that power on 3 15s expecially if your doing a wall and can do lots of port area . and by the way i have 3 powerbass 4ks and three 12s" xls , my coil is D2 so each amp is at 1 ohm before rise