KEF R400b Subwoofer


*Please check with our online customer service team or your local store for stock availability


At just 14 inches cubed, the KEF R400b may be compact, yet it packs an incredible punch. With a reinforced and 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 a ‘force cancelling’ effect. This means the opposing reactive forces are nullified, resulting in no cabinet agitation and a clean, fast, powerful bass performance - perfect for any serious home theatre system.


    Designed from the ground up, the R series is a towering leap forward that creates a new dimension in sonic authenticity.

    The geometry and bracing of the enclosure optimizes vibrational behavior, reducing secondary radiation from cabinet walls for a cleaner sound. Damping panels further minimize cabinet resonance and coloration.

    Front baffles are clean with no visible screws. Grilles are fixed magnetically. Available in real Walnut and Rosewood veneers, or highly polished Piano Black, the R Series complements the home as much as it respects the music.


    Dynamic, uncompressed and undistorted bass of heart pounding clarity envelops you, striking deep emotional chords. Your soul will awaken and the earth will move.


    Massive, vented magnet assemblies and large aluminum voice coils drive the lightweight yet stiff, strong hybrid cones. Bass output is faster, cleaner and more accurate. Satin anodised elements contribute to the unit’s elegance, while the diameter of the trim ring accentuates a visual sophistication that belies the speaker’s awesome power.


    Force cancelling drivers avoid cabinet agitation. Opposing reactive forces are nullified by rigidly mounting the low frequency drivers back-to-back.


    The R Series presents the high-end technologies of KEF BLADE in a timeless, elegant format. Serious audiophiles can now enjoy phenomenally accurate reproduction that neither adds nor subtracts from the original recording. Indulge in the R400b experience at a price that will also be music to your ears.

    Refined, spacious and exquisitely detailed, you won't just hear music the way it was intended it to be. you'll live it, feel it and love it.

    • Design: Powered Subwoofer (Sealed)
    • Drive Units: Bass units:
      • LF: 2 x 225mm (9in.)
    • Frequency Range: 26Hz - 140Hz (-6dB)
    • Maximum Output: 111dB
    • Recommended Amplifier Power: 2 x 250W (500W) built-in Class-D
    • Low Pass Filter Variable: 40Hz - 140Hz, 4th-order
    • Low Level Signal Inputs:
      • RCA phono sockets
      • Speaker level inputs
    • Internal Volume: 22 litres
    • Power Requirements:
      • 100V - 120V / 220V - 240V
      • ~ 50 / 60Hz
    • Power Consumption: 600VA
    • Dimensions: 365 x 330 x 351 mm (14.4 x 13 x 13.8 in.) with terminal & plinth
    • Weight: 21.5kg (47.4lbs)

Next Previous