Acoustic Audio HDS8 8-Inch In Wall Kevlar Subwoofer (White) Acoustic Audio HD-S8 passive in wall sub speaker, recommended power is 20-250 watts, frequency response is 30Hz-200Hz, efficiency is 98dB, 8ohm, spring loaded speaker wire terminals 8" woofer, woven fiber bulletproof cone, butyl rubber surround for increased performance, paintable frame and grill, low profile housing, instructions included Integrated wall-lock mounting system, cut out template included, cut out is 9.75" x 9.75", overall is 11" x 11", mounting depth is 4.25", designed and engineered in the USA Use for in wall or in ceiling home entertainment, surround sound, home theater, multiple room systems, industrial sound systems This listing and price is for 1 in wall passive sub speaker, this passive sub requires the WS1005 sub amplifier or a sub amp with similar specifications