DESC: With an ultra-reliable, high efficiency, 250W class D amplifier powering a 250mm (10in.) driver with a matching auxiliary bass radiator, the radical HTB2 model subwoofer anchors the 3D sound image with stunningly realistic low frequency reproduction. The HTB2 will play loud and clean all day long. Whether you prefer to position it vertically or horizontally, the story's the same: an acoustically inert enclosure shaped to eliminate internal standing waves, extremely fast response and SmartBass "connect and go" versatility with simple bass boost and phase controls.