This is a serious sub-woofer. It features a 15-inch downward firing driver with onboard amp. Adjustable volume, phase and high end cutoff. Most subs feature an acoustic suspension design (insensitive and difficult to drive, slow response) or ported design (one-note bass). The Tsunami 15 is a transmission line design. It contains an eighteen foot internal, folded transmission line giving all the detail in and nuances of the bass with rapid response to input. Measured response 16 Hz at the driver and 13 Hz -3dB at the vents of the transmission line. Includes input cable. Not only suitable for home theatre but for serious hi-fi. 220/230V.