Boston Acoustics Horizon Series HPS 10SE Midnight Speakers (Discontinued by Manufacturer) High-output front firing, rear ported Deep Channel Design (DCD) drivers BassTrac circuitry for tight, distortion-free bass at all output levels Frequency Response (3dB) - 35Hz-150Hz Bass Unit - 10 (254mm) DCD Subwoofer Crossover - 40Hz-180Hz 24dB/octave low-pass