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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

44

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K7262 REF 209208 Combined Manual_v2  12/2/08  12:40  Page 44

Summary of Contents for REFERENCE 208

Page 1: ......

Page 2: ... on top of this apparatus Do not install near any heat source such as radiators stoves or other appliances that produce heat Ensure that the power plug and cord are correct for your sockets Do not use if they show any signs of damage This device complies with Part 15 of the FCC Rules Operation is subject to the following conditions 1 this device does not cause harmful interference and 2 this devic...

Page 3: ... use To completely disconnect the apparatus from supply mains the plug must be removed from the mains socket outlet completely Important Safety Instructions Important Information Thank you for purchasing this KEF Reference Series subwoofer It has been designed to faithfully reproduce high quality sound over many years of use Please take a little time to read these instructions prior to use Your KE...

Page 4: ...ol and Control Functionality 16 Connections Setup and Fine tuning 18 connection diagrams movie only setup through the LFE input music only setup through the Left Right input combined movie and music setup connecting to the speaker inputs high level Using the Preset Equalization options 22 Using the Room Correction facility 23 Grille 24 Warranty 24 Service Information 24 Specifications 25 Reference...

Page 5: ...sure is beautiful on the outside and highly technical on the inside Attached to the inner surface are 30 ACE modules tubes of activated carbon which increase the effective internal acoustic volume by a factor of 2 ACE technology see page 8 is KEF s solution to the oldest catch 22 in loudspeaker design that to get good bass extension with good efficiency you need a large enclosure The Reference Ser...

Page 6: ...ules In fact the bass quality of ACE loaded enclosures is consistently admired by audiophiles for its clarity and detail Room Correction The listening room has a major impact on the sound of loudspeakers particularly at low frequencies In this region standing wave resonances in the room result in large peaks and dips in the loudspeaker response It is very difficult to compensate for the effect of ...

Page 7: ...F care pack is included with the subwoofer This pack contains a cleaning cloth and all the required accessories for connecting and positioning your Accessories sunlight should if possible be avoided Furthermore the cabinet should not be allowed to become wet Each Reference Series 209 subwoofer is supplied with KEF designed substantial spikes and locking nuts also in the care pack This enables fine...

Page 8: ...is is where the room correction feature on the Reference Series 209 subwoofer becomes such an important feature As the sub bass low frequency sound produced by the subwoofer is close to omni directional positioning of the subwoofer is less critical than with full range conventional speakers However it is advised that the subwoofer is not positioned too close to the listener It is often recommend t...

Page 9: ...mplifier and the KEF Reference Series 209 subwoofer or use the Line level LFE input described below Line input LFE This dedicated line level input is specifically for LFE Low Frequency Effects output from a surround sound processor Please note that single ended phono or balanced XLR connections are available however they must not be used simultaneously The LFE input to the subwoofer is not be affe...

Page 10: ...d are not applicable to the LFE input where it is assumed an external surround sound processor is controlling the bass management externally L R EQ Selects the Equalisation EQ that is applied to the LEFT and RIGHT line level inputs There are 7 different EQs as defined on page 22 The subwoofer will default to the standard flat EQ unless an alternative is selected LFE EQ Selects the EQ that is appli...

Page 11: ...to switching the amplifier ON L R L R L R L R Stereo line level connections Stereo speaker level connections L R C SUB LS RS L R C SUB LS RS LFE line level connections For use with bass limited small main loudspeakers LFE line level connections For use with full range large main loudspeakers K7262 REF 209208 Combined Manual_v2 12 2 08 12 40 Page 18 ...

Page 12: ...level input is specifically for the LFE Low Frequency Effects output from a surround sound A V processor Please note that single ended phono or balanced XLR connections are available however they must not be used simultaneously The LFE input to the subwoofer will not be affected by the frequency or slope settings which apply only to the Left and Right channel line inputs Once your subwoofer is con...

Page 13: ...position Please note that you can press SETUP at any point to abort the room correction process and stop the sweep sounding Connect the supplied KEF microphone with the supplied XLR lead to the rear of the subwoofer Press room correction SETUP on the remote control Remove the grille and place the microphone 2 inch 50mm away from the subwoofer driver Press SELECT and wait whilst a sweep is sounded ...

Page 14: ...e suction vacuum cleaner with soft brush attachment Your Reference Series Model 209 subwoofer is guaranteed against manufacturing defects in both materials and workmanship For further details of how this guarantee affects you please read the enclosed Warranty leaflet It should be noted however that failure of the loudspeaker due to abuse improper or inappropriate use and or operation or damage cau...

Page 15: ...W Class D amplifier has been custom designed to form a seamless partnership Utilising a switched mode power supply top end performance can be delivered in a highly efficient unit without compromising cabinet design The acoustically inert cabinet is beautifully hand finished with a level of craftsmanship and attention to detail that complements the precision of the components it contains The Bass r...

Page 16: ...ou should notify your retailer or consultant immediately Retain the packaging in case a need arises for you to transport the subwoofer at a later date You will notice that a special KEF care pack is included with the subwoofer This pack contains all the required accessories for connecting and positioning your loudspeakers The care pack Accessories Each Reference Series 208 subwoofer is supplied wi...

Page 17: ... rock at all Subwoofer Positioning The listening room is one of the most variable elements in the hi fi chain and its effect cannot be emphasised too strongly nor can its effects be reliably predicted As the sub bass low frequency sound produced by the subwoofer is close to omni directional positioning of the subwoofer is less critical than with full range conventional speakers However it is advis...

Page 18: ...ly for an LFE Low Frequency Effects output from a surround sound processor Please note that single ended phono or balanced XLR connections are available however they must not be used simultaneously The LFE input to the subwoofer is not affected by the frequency or slope controls and it will not therefore conflict with the bass management settings applied by the external surround sound processor Gr...

Page 19: ...ases the internal low pass filter cut off frequency in the subwoofer between 40Hz and 140Hz so that it integrates smoothly with the main speakers It is only applied to the Left and Right inputs and is not applicable to the LFE input where it is assumed an external surround sound processor is controlling the bass management externally Subwoofer Satellite Integration Correct Subwoofer Satellite Inte...

Page 20: ...to switching the amplifier ON L R L R L R L R Stereo line level connections Stereo speaker level connections L R C SUB LS RS L R C SUB LS RS LFE line level connections For use with bass limited small main loudspeakers LFE line level connections For use with full range large main loudspeakers K7262 REF 209208 Combined Manual_v2 12 2 08 12 40 Page 36 ...

Page 21: ...the controls whilst listening to a varied selection of music until you are satisfied with the sound balance Combined movie and music setup The Reference Series 208 subwoofer can be used for both main speaker low frequency extension and the LFE channel reproduction for a surround sound system Set the subwoofer up as described in section Music Only Setup With the subwoofer correctly set up for stere...

Page 22: ...the loudspeakers and therefore when faults occur careful and analytical diagnosis will be required to locate the actual source of trouble Faults in a loudspeaker will be audible on all programme sources A fault which is evident only when playing CDs but not for example when using a radio tuner is unlikely to originate with the loudspeakers Service problems should be discussed in the first instance...

Page 23: ...using it as the surround to the loudspeaker diaphragm while using new materials for the diaphragm itself Cooke was always looking for new materials and settled on Bextrene as a solution as its lightweight plastic sheet like properties were flexible enough for shaping and the material remained stable under varying temperature and moisture conditions and was smooth and consistent over a wide bandwid...

Page 24: ...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 hug...

Page 25: ...wledge that all of his original and noble principles remained intact and would always do so Recognition that year for the Reference Series Model Four had reached a peak with world wide acclaim Reviews by internationally famed and respected writers were quick to praise the merits of the company s new flagship model with its fourth generation Uni Q driver and to point out the sheer engineering excel...

Page 26: ...ion the presence of the granules makes each enclosure sound twice as big as it actually is Yet more KEF innovations soon followed The KIT KEF Instant Theatre concept for example proved an immediate hit an integrated multimedia home entertainment system for consumers who want a complete user friendly package that offers quality sound without being complicated to set up One of the most revolutionary...

Page 27: ...K7262 REF 209208 Combined Manual_v2 12 2 08 12 41 Page 50 ...

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Page 29: ... Heinrichstraße 51 D 44536 Lünen Deutschland Tel 49 0 231 9860 320 Fax 49 0 231 9860 330 GP Acoustics France SAS 39 Rue des Granges Galand BP414 37554 Saint Avertin CEDEX France Tel 33 0 2 47 80 49 01 Fax 33 0 2 47 27 89 64 GP Acoustics HK Limited 6F Gold Peak Building 30 Kwai Wing road Kwai Chung N T Hong Kong Tel 852 2410 8188 Fax 852 2401 0754 KEF JAPAN 1 11 17 Honcho Koganei City Tokyo JAPAN 1...

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