The 215RT posts some huge numbers, but anyone using it is going to need some heavy duty amplification. The impedance dips are pretty demanding, dipping below 3 Ohms from 55 Hz to 80 Hz, which is a heavily used range as it serves as the fundamental note for many bass lines. I would not be hooking that thing up to a run-of-the-mill AVR, but then again, I doubt anyone who buys these things will be doing that anyway. I managed to hear one of these things at a past AXPONA show, very nice speakers.