Polk DSWPRO 550wi Wireless-ready Powered Subwoofer DSWPRO Series enclosures are designed and engineered for perfect volume, minutely tuned for distortion-free low frequencies, and internally braced and damped to eliminate internal standing waves and other performance-robbing resonances Polk intelligent amplifiers require less power to sound great, use power more efficiently and know when to stand down (especially at low volumes or in "Standby" mode) Feed forward distortion suppression technology enables us to set our performance limits much higher than normal, much closer to the actual (theoretical) maximum output of the subwoofer, with no risk of excessive distortion or damage Choose one of four preset "Room Optimizers' from the remote controller, and Polk's exclusive PRO technology programs in the optimal bass and blending setting for your room DSWPRO subwoofers can be arranged with their feet forward or down, for standard downward-firing position or innovative front-firing mode (you can snap on the grille and it looks smart) that lets you can place the subwoofer just about anywhere