Not a fan of Rockford. Its inefficient, heavy and power sucking technology. Watt per watt, they can't compete. You know why the magnets on Rockford are so huge? Cause they use the cheapest/weakest magnet they can get their hands on. If you want shake, buy Rockford. If you want sound, buy something else like JBL GTi's. Its NOT about how much power the voice coils will peak at, its about how much it will RMS and how many db it produces with that power and how clear and tight the sound is. Yes, subwoofers need sound quality too.