They are nice subs.They are pretty underrated, a friend of mine is giving the a good 1000rms each.Around 1200 or so they reach the limits as far as music.They are geared to perform like L7s,and other main stream subs.If I had the room I would sell my hd3s and do 4 2.5 15s,but I dont have the room so I gotta find some mo powa for the hd3s