By 1973 the company was developing the
concept of computer assisted ‘Total System’
design, at a time when the world’s very first 4-bit
microprocessor was still in its infancy.
KEF engineers, using a given set of parameters,
could for the first time actually “see” what the
response characteristics of a loudspeaker system
would be. KEF was the first loudspeaker
company in the world to take the new
technology seriously in order to achieve this.
Now it was the use of computers and digital
test methods which provided the KEF engineers
with the relevant crossover and drive unit
data at a glance, thus dramatically improving
their ability to produce loudspeakers of
outstanding accuracy. Amongst other benefits,
KEF loudspeakers could now be computer
matched as an almost identical pair - to within
one-half of a dB.
1973 then saw the introduction of the first KEF
Reference Series Model, the 104 which swept
reviewers, distributors, retailers and customers
off their feet. The archetypal ‘domestic monitor’
104 provided the standards of a broadcast
monitor loudspeaker in a domestic package,
probably for the first time.
With the installation of a Hewlett Packard
computer at the Maidstone Head Office in 1975,
the Corelli, Calinda, and Cantata were all
designed under the total system concept and
with them came a second Queen’s Award for
Export in the same year.
1977 saw the most radical KEF design yet in the
Model 105 which apart from setting new
standards for flat frequency response introduced
a design by which the mid and treble were split
from the bass box and placed within a contoured
moulded enclosure above the bass enclosure.
The added ability to angle the separate unique
head unit provided the opportunity for the user
to tailor the 105 to his or her own environment.
The loudspeaker was of such general importance
and consumer interest that a leading quality UK
Newspaper, The Daily Telegraph, featured the
Model 105 on the front cover of its magazine
supplement. More Reference Models were to
follow. 1978 saw the launch of the 101 and
103 and, in 1979 a further refined 105/2
Model appeared.
Ten years of growth world-wide followed,
peaking with a massive onslaught on the lucrative
and influential US market in 1985 with the
setting up of KEF Electronics of America, seen as
the appropriate recognition of this important
market-place.
1986 saw more activity amongst the now world
famous KEF Reference Series; the 104/2, always
regarded as one of the world’s truly outstanding
loudspeakers since its 1984 launch spawned the
107, in reality an evolution of the 105/2 but with
KEF’s coupled-cavity bass loading, a system
which positions the drivers internal to the
enclosure, each separately loaded and firing into
a third common chamber which delivers very
tight and accurate bass to the listening area via a
substantial front-mounted port. This combines
the taut sonic character of a sealed box with the
higher sensitivity of a reflex design and succeeds
in providing a huge boost to bass performance.
Also came the 102 and the 103/3, both accepted
by recording and broadcast engineers as
ideal monitors. KEF’s reputation as
loudspeaker engineers was set in stone.
As well as the coupled-cavity bass loading
system, KEF Reference loudspeakers boasted
such highly sophisticated features as a conjugate
load network technique, which makes even a
complicated loudspeaker design simplicity itself
from the amplifier’s perspective and a heavily
damped midrange module which preserves low
coloration and fine stereo. A force cancelling
rod, fitted between the vertically opposed bass
units was an added introduction, eliminating the
possibility for coloration caused by woofer
vibrations exciting the enclosure panels.
Amidst all this excitement, 1988 also brought in
the birth of the KEF Custom Installation
loudspeakers, a move made in response to new
world market demands. The same exacting
engineering standards were naturally applied to
the range and the CR200F and its sub-bass
partner, the CR250SW set new standards from
in-wall/ceiling units.
Then, again in 1988, came Uni-Q. A design
process, painstakingly evolved by KEF over
several years, by which a single point source at
last became a reality. The HF units made use of
a rare-earth magnet material, Neodymium/
Iron/Boron which was developed for the NASA
Space Programme.10 times more powerful than
a conventional loudspeaker magnet, this material
allowed KEF engineers to make a tweeter small
enough to fit within the bass unit coil former at
the precise acoustic centre of the cone.
KEF’s Uni-Q technology delivered well-defined
stereo imaging over a much wider listening area
without the need for the time honoured sacred
“hot-spot” in the listening room. The 105/3 was
a massive success, bringing together, not just
Uni-Q (now in its second generation form),
but all of KEF’s magnificent technology -
coupled-cavity bass loading, conjugate load
matching, force cancelling rod, computer
matched crossovers and drive units, even hand
pair-matched veneer finishes - in fact almost
everything by which KEF had made its name as
the world’s foremost loudspeaker company -
in to one product. It was voted Best Imported
Speaker by the Japanese Press in 1992.
‘Total System’ design testing equipment
The Model 105/3
The 1970’s The 1980’s
Uni-Q Technology
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