Use a pair of these THX ®-certified, 1 kilowatt powered subwoofers as part of a complete HT home theater system to deliver thunderous, penetrating, undistorted bass that will shake the floor. The HTPS-400 accurately reproduces the special low frequency effects that generate the excitement of the movies. 25Hz to 250Hz of pure, distortion-free bass will deliver a lesson in movie excitement that your bones and teeth won't soon forget.