When it comes to thundering power, the RSd Competition Series Subwoofers have it all. From an expanded polypropylene cone that's more responsive while delivering superior dampening. To the tri-flow voice coil air venting giving you more power for longer. And the high excursion butyl rubber surround, providing lower distortion at higher sound pressure levels. Every detail has been engineered to give you a subwoofer that performs at the level of one costing three times as much.