Rms coil ratings aren't too important in when determining how much power a subwoofer "needs", in my opinion. Heck, I'm using an old xxx on 400w and I can get it to rattle my room apart. I even used it in the car on 2 channels of a kx350.4 and played way over what I can call decent. Funny thing is, if he gets the BL now and upgrades to a much more powerfull amp in the future, he's going to be ask himself why he didn't buy the BTL in the first place... Well i have planed to buy a Audioque 3500D,think it will have power to make the BTL or the BL dance,if i am happy with the Subwoofer i might just add a new one.