KEF knows how important great bass is when you're listening to tunes or watching a movie. They've designed the KUBE 8b powered subwoofer to provide excellent low-end performance without taking up a lot of space on your floor. This compact sub is an excellent choice for small- to medium-sized rooms where space is at a premium.
The KUBE 8b is outfitted with a custom-designed 8" woofer, and a powerful 300-watt RMS amplifier. KEF designs and builds all of their components in-house to make sure that both the quality and audio performance are up to the company's high standards. 
Product highlights:
frequency response: 34-140 Hz (-6 dB)
built-in Class D amplifier delivers 300 watts RMS of continuous power
custom-designed 8" woofer
acoustic suspension (sealed) cabinet design
iBX (Intelligent Bass Extension) digital signal processing provides deep, dynamic bass at any listening level
3 placement presets (free standing, in-cabinet, or corner) let you choose your sub's location for optimal bass performance
variable low-pass crossover (40-140 Hz)
phase control switch (0-180°)
line-level/LFE RCA inputs
main power on/off switch plus auto standby/on mode
detachable power cord
11-1/2"W x 11-1/2"H x 12-1/4"D
weight: 25 lbs.