it dpends on the sub really and the box. IF the box is ported you'll most likely not notice the difference in power. BUt if you go sealed which would require more power to the sub. But like i said the brand on the sub matters to. THat rms could be thermal or mechanic. Becasue take for instance the brahma. Says 1600w rms but you could put half the power to it, in a nicely built box, and it'll hit full excursion.