● The Matrix 800 Active Subwoofer, which is THX® approved, is an essential component for the definitive Home Cinema system. It delivers bass sound of true intensity, dramatically improving impact, presence and detail in the whole system. If there is an earthquake on the screen, there's one in your living room. ● The Matrix 800 ASW is Acoustically Voice Matched to be an integral part of the Matrix 800 Series. Magnetic shielding enables the subwoofer to be placed close to a television or video monitor without interference.