OSD Audio PS12 High Powered 12-Inch 175W Powered Premium Home Theatre Subwoofer, Black Matte Finish POWERED SUBWOOFER - Easily connect to a home theater receiver, no amplifier needed. POWER OUTPUT - Continuous Power 175W (RMS) / Dynamic Peak 300W. ADJUSTABLE GAIN CONTROL and VARIABLE CROSSOVER FREQUENCY - Set between 25Hz and 180Hz. AUTO-ON SENSING - This feature allows the subwoofer to remain on.