KEF's KC62 subwoofer is a compact, state-of-the-art bass-maker with big ideas

KEF has announced a new subwoofer due to hit shops this February that the audio specialist says has ‘changed our expectations of subwoofer design forever.’

Dubbed the KEF KC62, and priced £1,400, the sub is a compact, dual-driver design with the promise of ‘unprecedented depth and breath-taking accuracy.’

Buried within is a trio of new patent-pending technologies – the most notable being something the brand calls Uni-Core, which has been designed to allow two bass drivers to operate within a smaller-than-usual cabinet.

This is achieved by mounting both of the KC62’s 6.5in woofers on a single motor, using concentrically arranged, overlapping voice coils. Due to the size difference between the coils, when the driver cones move backwards (in a force-cancelling config), the coils ‘can occupy the same space within the cabinet,’ and the drivers can have a greater excursion than in a conventional design.


This has enabled KEF to build a glam-looking extruded aluminium cabinet (available in either Carbon Black or Mineral White) measuring a mere 246 x 256 x 248mm (wxhxd).

Adds Dr Jack Oclee-Brown, KEF’s head of research and development: ‘To deliver deep and loud bass from a compact product is a big engineering challenge. The Uni-core is a breakthrough technology for KEF because it allows us to pack two drivers into a tighter space without compromising their performance.’

Doubling up on power
Driving the twin woofers is a 2 x 500W Class D amplifier stage. The sub is rated down to 11Hz (-3dB) and suggested for use in movie rooms up to 50m2.

Two further new technologies make their debut on the KC62 – P-Flex Surround (AKA Origami Surround), and Smart Distortion Control. The former is a patent-pending driver surround that’s ‘uniquely pleated’ to resist pressure built up inside the cabinet, increasing woofer sensitivity. The latter is a motion feedback system that measures voice coil current to correct ‘non-linear distortions’.

‘The new approach reduces the interaction between signal, amplifier and driver, which dramatically decreases the potential for distortion,’ says KEF.

Additional features of the KC62 include in-house-designed Music Integrity DSP engine (with Intelligent Bass Extension technology), compatibility with KEF’s KW1 wireless transmission kit, and five Room Placement Equalisation presets designed to achieve an optimal performance regardless of where the woofer is sited.

Says KEF: ‘Deep and powerful bass is no longer solely the domain of big-shouldered, massive subwoofers.’