KEF R400b Subwoofer
 At just 14 inches square,  the KEF R400b may be compact,  yet it packs an incredible punch. With a reinforced & braced sealed cabinet,  the R400b houses twin 9-inch LF drivers powered by twin 250W class-D amplifiers. The drivers are mounted back-to-back,  to create ‘force cancelling’. This means the opposing reactive forces are nullified,  resulting in no cabinet agitation & a clean,  fast,  powerful bass performance – perfect for any serious home theatre system.
 
 
 Model R400b
 Design Powered Subwoofer (Sealed)
 Frequency range (-6d B) 26 Hz
- 140 Hz
 Maximum output 111d B
 Amplifier 2 x 250W (500W)
 built-in Class-D
 Low pass filter Variable 40 Hz
- 140 Hz,  4th-order
 Low level signal inputs RCA phono sockets