The HST-11 mkII subwoofer is specifically designed for being able to play from 90 Hz down to 5 Hz in an extremely small sealed enclosure size of 0.5 ft^3 with ease and extreme authority. 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-11 mkII uses the same motor as our massive HS-24 mkII uses with the same two aluminum shorting rings with an additional item to eliminate eddy currents to control and linearize inductance for improved transient performance. The voice coil of the HST-11 mkII uses four layers of flat aluminum wire wound on a black anodized aluminum former. 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.