owenmakenna , I assume you have two 12's? Also are your subs sealed or ported? What size box? If I go with two 12's I will use two Tru Tech S500s rated at 500 rms but speck out over 700 rms. Is that enough for these subs. I am not looking to break the windows, but if I compete in an SQ class I believe I need to hit 135 db. Thanks for your help, John