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KEF Reference – an engineer’s perspective

  • Kent Engineering and Foundry. KEF was founded by ex-BBC engineer Raymond Cooke in the 1970s; Cooke was one of the first to apply computer-modelling techniques to loudspeaker design, continued to this day by KEF’s R&D team who remain based in Kent despite the company now being owned by Hong Kong’s GP Acoustics.

    Almost twelve months after its debut at the Munich High End Show and nine since its first appearance Stateside at the New York Audio Show 2014, KEF’s all-new Reference series has finally arrived in Australia. That’s a launch event hat trick for this journalist.

    How the 2014 Reference series breaks down into two D’apollito-configured floorstanders (Models 3 and 5), a standmount (Model 1), a centre speaker (Model 4C) and a subwoofer (Model 8B) has already been detailed in last year’s Munich and NYC coverage but if you’ve a thirst for a more recent press-release-induced summary that includes freshly-announced Aussie pricing, head on over to DAR’s Australian subdomain.

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    Johan Coorg introduces the 2014 KEF Reference range at the New York Audio Show (September 2014).

    At the Sydney Hilton launch event, Michael DiMeglio of Advance Audio Australia – KEF’s local distributor – introduces George Perkins, one member of the Kent engineering team’s fountain of youth headed by Jack Oclee-Brown. With KEF now being in the financial hands of Hong Kong’s GP Acoustics, GP’s Asia Pacific director of sales Jessica Chua is also on hand for follow-up questions.

    Clearly a little nervous about standing in for brand ambassador Johan Coorg – who fronted presentations in Germany and the USA –  Perkins opens with softly spoken intent: “I’m not a marketing bod so I’ll just sit down whilst I talk you through some details”. Ha!

    It’s all part of the promotional wheel – sure – but the Kent-based engineer brings a fresh perspective. Perkins isn’t as much of an exhibitionist as Coorg but he spills with hitherto unknown morsels of information about Reference, which remain hooded for the first section of his presentation.

    The Reference series (“Keference” anyone?) has been the engineering backbone of KEF’s product line ever since a first version launched down under in 1974 at the then just-opened Sydney Opera House. Perkins explains how there’s no change for the sake of it at KEF and that updates to Reference have been less common in recent years. We have to travel back ten years to find its previous incarnation, apparently a “VERY different” animal to these newer models.

    Perkins explains that this latest Reference series is “heavily influenced by Blade”, the motivation for which was two-fold: 1) the loudspeakers need to communicate the emotion and artistry of music and 2) they need to do so in peoples’ homes (and not just the lab).

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    George Perkins explains some of the finer technical points of KEF Reference to a Sydney audience (April 2015).

    How does KEF shoot for such lofty goals?

    Perkins explains how a smooth, balanced frequency response is essential, even off-axis for which KEF’s Uni-Q array, now in its 10th generation, plays a key role. “These drivers must behave well,” says Perkins, “Sound must come only from the driver and NOT the cabinet”. “The driver must also have low distortion”, he continues, for which the metal cone is decoupled from the voice coil outside of its usable bandwidth.

    With rectilinear cabinets back on the Reference menu, a waveguide surrounds the Uni-Q array to minimise cabinet edge diffraction.

    KEF also deploys ‘constrained layer damping’ inside each cabinet – a technology apparently borrowed from the super-popular LS50 standmount that sees a damping material placed between brace and cabinet that turns vibrations into heat.

    Finally, Perkins explains how the rear port design was optimised using computational fluid dynamics. Not one but two port bungs ship with each Reference speaker: the longer one provides a classic ‘sealed box’ sound whilst the shorter version serves up greater bass punch.

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    Like the more progressive-looking Blades, the Reference models are all handmade in the UK, not China. That’s both cabinets and drivers – well, almost. The front baffle, a composite of aluminum and polymer, is sourced from a high-end Italian furniture company.

    We wrap with a short music demo. Perkins showed off the bigger Model 5 floostanders using a fairly broad selection of tunes: Ray La Montagne, Boris Blank of Yello, UK electronic popsters London Grammar and an unnamed classic piece. Polite these speakers are not – there’s plenty of lapel-grabbing excitement to keep the press gang from nodding off into their lunchtime whiskys, neatly poured into KEF branded glassware.

    Further information: KEF | KEF AmericaKEF Australia

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    Michael DiMeglio of KEF’s local distributor, Advance Audio Australia.

     

    Written by John

    John currently lives in Berlin where he creates videos and podcasts for Darko.Audio. He has previously contributed to 6moons, TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

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