The KPT-884 is a high output, bass-reflex cinema subwoofer that features an advanced low-frequency 4-inch voice coil driver design. Less than 23 inches in depth, this system utilizes a single 18-inch driver that gains its high efficiency through the use of large, geometrically optimized structures and light-weight cones. In fact, the KPT-884 is capable of delivering an earth-shaking low frequency of 18Hz.