LOUDSPEAKERS
I
t started with a mass-produced polystyrene
cup, the kind used for hot drinks, made
by vacuum-forming a foamed plastic over
a shaping tool. These were patented in the
USA back in 1957, at which time one Raymond
Cooke (pictured above right) was designing
loudspeaker drive units as Technical Director of
Wharfedale, a position he’d taken after working
for the BBC’s Designs Department. By 1960 the
humble polystyrene cup had made its way across
the Atlantic, and when Cooke first saw one,
the proverbial light bulb illuminated above his
head. At the time his loudspeaker driver cones
were made from paper pulp, using a process that
was expensive, time-consuming and difficult to
achieve consistency. But suddenly, here was a new
technique, a new material, and one capable of
mass production. Could drive units be formed in
the same way?
His Wharfedale masters being unresponsive to
his excitement, in 1961 Cooke left the company
and set up his own at the Kent Engineering and
Foundry. KEF Electronics was born.
Over the decades that followed, KEF’s success
spoke for itself. From its first ‘slimline’ speakers to
its reference designs and on to wildly-successful
midrange hi-fi with the likes of the long-runningCoda series, Cooke’s engineering focus and materials
research paid dividends in delivering both state-of-
the-art technologies applicable to both the heights
of loudspeaker design, and value-for-money core
hi-fi products. Others also used KEF’s revolutionary
drive units. At Cooke’s old BBC stomping ground,
the now-legendary LS3/5A studio monitor used
KEF drive units made from Bextrene, a lightweight
acetate plastic sheet derived from wood pulp. The
LS3/5A set the ‘BBC Standard for Loudspeakers’,
and remains a respected design to this day.THE ORIGINAL LS50
So when KEF celebrated its anniversary in 2011,
50 years after its founding and 15 years on from
Cooke’s passing, it was more than appropriate to
honour the occasion with a new loudspeaker that
took design inspiration from that classic BBC/KEF
collaboration, the LS3/5A studio monitor.
The result, KEF’s LS50 ‘Anniversary’ speaker,
was a gorgeously-designed and surprisingly
diminutively-proportioned standmount in a gloss
piano black finish, with a curved baffle covered in
a low-diffraction ‘rubber-like’ material. This small
monitor, aimed squarely at the high-end market,
also featured a new copper-coloured 130mm version
of KEF’s Uni-Q driver, which here leveraged trickle-ACTIVE WIRELESS
STEREO LOUDSPEAKERSKEF LS50W & LSX active wireless stereo speakers
down technology from the recent mighty Blade
(above right), KEF’s flagship.
The Uni-Q driver concept, which sits the
tweeter within the midrange driver in a deviation
from the standard coaxial, has long set KEF apart
from the crowd. This point source driver array,
where all sound is aligned as if originating from
a single point in space, has claims to outstanding
acoustic clarity and off-axis dispersion in
particular. The normal arrangement of separate
drivers causes different amounts of interference
with each other depending on the listening
position (hence the notion of a central ‘sweet-
spot’). With the coaxial Uni-Q, the sweet spot
becomes far less crucial. KEF has continuously
developed the concept for more than 20 years.
In the LS50 Anniversary speaker, it delivered
not only exceptional clarity of sound, but
remarkable frequency response. When Newport
Test Labs measured its performance for Australian
Hi-Fi magazine, it reported results that were
“simply outstanding for all measurements, par-
ticularly the incredible flatness and uniformity of
the frequency response and the almost unheard-of
bass extension from such a small speaker”.
As a relatively small monitor speaker, the LS50
did not defy the laws of physics by digging intoKEF’s active speaker revolution began with the LS50, created to
celebrate 50 years of loudspeaker engineering. Nearly 10 years on
from that, the addition of wireless has made KEF’s LS50W and latest
LSX wireless speakers simple but spectacular hi-fi system solutions.