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KEF KC62 Uni-Core Force Cancelling Subwoofer
Foto © KEF

KEF KC62 Uni-Core Force Cancelling Subwoofer

KEF KC62 Uni-Core Force Cancelling Subwoofer, this new subwoofer from the English speaker specialists is set to change the rules of subwoofer design forever, KEF is convinced. Powerful, deep bass is no longer the domain of massive, huge subwoofers. Three innovative technologies are designed to make this possible: KEF Uni-Core technology, KEF P-Flex Surround and KEF Smart Distortion Control technology.


KEF, the English loudspeaker specialist, has just introduced a new innovative technology that is supposed to offer unprecedented performance in bass drivers, the KEF Uni-Core technology. The highlight of this new technology is that it can be used to realise particularly compact, but very powerful bass solutions. Deep and powerful bass is no longer the domain of huge, bulky subwoofers. The new KEF Uni-Core technology represents a new milestone in the development of powerful subwoofers.

The first KEF solution to use the KEF Uni-Core technology is, of course, a subwoofer, and an exceptional one at that – the KEF KC62 Uni-Core Force Cancelling Subwoofer.

Don’t be fooled by the size, KEF says, as the new KEF KC62 Uni-Core Force Cancelling subwoofer is a prime example of the enormous power that can be achieved in a comparatively compact size based on KEF’s new Uni-Core technology. In addition, KEF has also introduced other exclusive technologies that it considers groundbreaking, such as KEF P-Flex Surround and KEF Smart Distortion Control technology.

So it’s three KEF innovations that make the new KEF KC62 Uni-Core Force Cancelling subwoofer a solution that changes the rules of subwoofer design forever. KEF is on record as saying that this puts the performance figures in complete contradiction to the subwoofer’s mere football-sized dimensions. The new KEF KC62 Uni-Core Force Cancelling subwoofer delivers both depth and breathtaking precision.

The focus is, of course, on KEF Uni-Core technology, a driver technology for which KEF has already applied for a patent. It uses a completely new interpretation of the traditional force-cancelling arrangement, ensuring that great performance is achieved in an ultra-small package.

In principle, the woofer of the new KEF KC62 Uni-Core Force Cancelling subwoofer is not one, but two drivers. KEF’s special Uni-Core technology combines both drivers in such a way that they are driven by a single magnet system, with the voice coils arranged concentrically. According to KEF, this allows the cabinet size to be reduced by a third while achieving, and in some cases exceeding, the driver excursion of a much larger subwoofer. Ultimately, more power and depth is extracted from less space.

The second KEF technology used in the new KEF KC62 Uni-Core Force Cancelling subwoofer is called KEF P-FLEX Surround, also known as Origami Surround. This refers to a completely new design of driver surround and is also patent pending. The KEF P-Flex surround is designed to withstand the acoustic pressure inside the cabinet better than conventional designs. How could it be otherwise, given the name Origami Sound, it relies on a unique folded design that counteracts internal air pressure without adding excessive mass. This ensures that the diaphragm can always move precisely and smoothly for detailed, accurate imaging.

KEF KC62 Uni Core Force Cancelling Subwoofer 13
KEF KC62 Uni-Core Force Cancelling Subwoofer

Also patent pending is the third new technology found in the new KEF KC62 Uni-Core Force Cancelling subwoofer, namely KEF Smart Distortion technology. This, as the name suggests, is designed to control, or at best avoid, distortion through intelligent technology. It’s sensorless Smart Distortion Control Technology, a groundbreaking motion feedback system that KEF claims corrects even the smallest anomalies. It measures the current in the voice coil to detect and correct non-linear distortion. This is said to reduce the total harmonic distortion by up to 75 per cent and to achieve precise, colouration-free bass reproduction at all times.

Another key component is the KEF Music Integrity Engine, a selection of custom DSP algorithms that further refine imaging. These include iBX (Intelligent Bass Extension) and SmartLimiter, which continuously analyse the signal and correct it for optimum driver control.

The DSP-based signal processing also allows an adjustment based on the subwoofer’s placement, referred to here as room placement. Five preset room placement functions are designed to ensure that the reproduction can be optimally adapted to the individual circumstances, such as free-standing placement in the room, against a wall, in a corner, embedded in a cabinet, or a special flat mode, as KEF describes in the data sheet.

Speaking of the data sheet, to understand why KEF is so euphoric about the new KEF KC62 Uni-Core Force Cancelling Subwoofer, two things need to be mentioned.

First, the dimensions of the new KEF KC62 Uni-Core Force Cancelling subwoofer, which measures no more than 246 x 256 x 248 mm and weighs in at 14 kg. That’s very, very compact for a subwoofer. The power rating doesn’t seem to fit in at all, as it is given as a whopping two times 500 watts RMS, i.e. a total of 1,000 W RMS, with a Class D amplifier module being responsible for this, of course. These are driven by two 16.5 cm drivers arranged in KEF’s Uni-Core Force Cancellation design.

To ensure that this power can actually be brought to bear, a correspondingly stable housing is required, so the developers decided on extruded aluminium. This is a closed construction. This also makes it possible to realise a particularly elegant shape with curved lines, thus ideally combining form and function.

The new KEF KC62 Uni-Core Force Cancelling Subwoofer is said to be able to reproduce a frequency range between 11 and 200 Hz, whereby it naturally has all options ready for optimal integration into the room, as well as optimal adaptation to other speaker systems, such as a variable low-pass filter (40 to 140 Hz), adjustment of the phase and the level.

The new KEF KC62 Uni-Core Force Cancelling subwoofer is also extremely flexible when it comes to connections, offering everything you need for a wide range of stereo and home cinema applications. Line-level/speaker-level inputs ensure that the subwoofer can be connected to any amplifier. The line output with HPF provides exceptional fine-tuned integration, while KEF SmartConnect eliminates any connection problems. The KC62 is also compatible with the KEF KW1 Wireless Subwoofer Adapter Kit, enabling wireless compatibility with a minimum of fuss, the manufacturer promises.

The new KEF KC62 Uni-Core Force Cancelling Subwoofer is scheduled to be available in stores as early as February 2021. Here, the customer can choose between a white and black version, whereby these are officially designated as Mineral White and Carbon Black, respectively.

The recommended retail price for the new KEF KC62 Uni-Core Force Cancelling Subwoofer is listed at € 1,500.

Getting to the point…

Maximum bass from minimum volume is the approach KEF is taking with the new KEF Uni-Core technology, first used in the new KEF KC62 Uni-Core Force Cancelling subwoofer. A subwoofer that is no bigger than a football, yet delivers rich, precise bass as if it were a much larger system. This is said to be helped by other technologies such as KEF P-Flex Surround and KEF Smart Distortion Control technology. In addition, KEF’s new subwoofer is extremely flexible when it comes to integrating it into a wide range of stereo and home cinema solutions. It can also be ideally combined with the KEF LS50 Wireless II and the KEF LS50 Meta II, especially as the design is very attractive, something that has rarely been seen in subwoofers before.

Manufacturer: KEF
Distribution: GP Acoustics GmbH
Price: € 1.500,-

About Michael Holzinger

Michael Holzinger, founder and editor-in-chief of HiFi BLOG and sempre-audio.com, has been working for years as a journalist in the fields of IT, photography, telecommunications and consumer electronics.

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