The HST-12 mkII is a subwoofer capable of playing effortlessly from 90 Hz down into the subsonic region in a very small 0.6 ft^3 sealed cabinet. With 38mm of one way linear excursion and 50mm of peak one-way travel this subwoofer has the stroke to keep up with deep bass demands. The HST-12 mkII uses the same motor as our massive HS-24 mkII uses with the same two aluminum shorting rings with an additional item which eliminates eddy currents and controls and linearizes inductance for improved transient performance. The voice coil of the HST-12 mkIII is a bifilar copper coil for a perfect balance of mass and motor force. Assisting voice coil cooling are six aluminum pillars which separate the basket from the frame and allow air to move around the OD of the coil. If you want great sounding, bone-crushing, super deep bass you have found your subwoofer with our HST-12.