KEF Muon loudspeakers: the inside story

KEF Muon: extraodinary looks and sound - for £70,000

Expensive, exclusive, packed with technology - sounds more like a recipe for a Mercedes or Porsche than a pair of loudspeakers. But that's exactly what KEF has achieved with its new Muon loudspeakers.

The 2-metre tall floorstanders cost £70,000 a pair; there are only 100 pairs in existence and they use cutting edge tech to deliver extraordinary sound quality.

That's the promise. What about the reality?

KEF's best of brand plan

KEF acoustics engineer Dr Andrew Watson says the Muon is the result of a series of acoustic experiments. The first fruit of those appeared as the Austin prototype at the Munich High End hi-fi show last year.

The big difference is that the Muon is made versatile aluminium, enabling KEF to overcome some of the constraints imposed by the more traditional wooden design of the Austin prototype.

The Muon has also arrived out of a desire to really show off KEF as a loudspeaker brand - to incorporate its best technology in a design that would appeal to a far wider audience than just a small audiophile clique.

"It's an enhancement of the brand," says Andrew Watson, "an off-the-wall design that will attract people who may not have considered KEF before."

Sound design

To help achieve that goal, KEF sought the involvement of industrial designer Ross Lovegrove helped the company come up with the unusual design suggested the use of formed super-formed aluminum - a material the designer had used before.

Lovegrove's input - while substantial - was placed under certain constraints. "The internal volume was fixed, the speaker drive units were fixed and the shape was fixed." says KEF's Dr Watson. "We wanted a 'waist' in the centre to improve the dispersion characteristics of the speaker." It was Lovegrove, however, who helped achieve the Muon's extraordinary final design.

Certainly Lovegrove's choice of super-formed aluminium looks to be a good one: it's acoustically rigid, and free from unwanted vibrations - an ability that can be enhanced by the use of internal bracing.

Acoustic Compliance Technology

It also enabled KEF to use its proprietary Acoustic Compliance Technology (ACE) - an active carbon coating inside the Muon's cabinet that absorbs air bubbles.

This enables the speaker to deliver a much bigger sound from a small enclosure than would otherwise be the case. It also helps improve the soundstage, particularly with bass sounds.

This enables a timpani drum playing in an orchestra to actually takes its correct place on the 'virtual stage' created by the stereo sound image. It's no longer confined to the box that's actually producing the sound.

KEF's actually been using Acoustic Compliance Technology for five years in its loudspeakers, and has been exploring the properties of active carbon for much longer - since the 1980s and 1990s, according to Dr Watson.

KEF Muon for all?

One of the aims of the Muon project has been for KEF to develop techniques that could filter down from its very high-end products to regular audiophile and mid-price loudspeakers. Dr Watson also hints that a home cinema version of the Muon maybe on the cards.

"As an acoustic engineer I can neither confirm or deny that is the case," he says. "However there have certainly been some discussions of the subject here at KEF and it would make common sense given our heritage."

For now the company seems happy to sell the Muon to those who design-obsessives who can afford the high cost of entry.

"Our aim is to get ourselves in touch with that market so they can see who we are and what we can do," says Dr Watson. " They're not necessarily audiophiles, but they are lovers of music and they want the best in technology and design."