KEF REFERENCE 107 - Introduction; General Notes

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INTRODUCTION
KEF Model 107 is a free-standing three-way loudspeaker system of the highest quality. The
system uses four drive units and includes active low-level equalisation in the form of
K-UBE (KEF Universal Bass Equaliser).
The low-frequency section comprises two 250mm units, linked by a force-cancelling rod,
mounted inside the main enclosure in Coupled Cavity configuration. This arrangement,
proven in KEF’s multi-award-winning Model 104/2, allows maximum power handling where
the musical demands are greatest, with exceedingly low distortion. Bass energy is vented
upwards at the top of the main enclosure. This obviates floor reflections which often lead
to over-prominent bass.
The midrange and high-frequency units are mounted in a separate enclosure above the bass
section. This head assembly is specially contoured to control diffraction effects. It
contains mineral-loaded polymer damping to eliminate mid-band colourations, and is
rotatable to permit precise focusing of the stereo image, independent of the orientation of
the main cabinet.
Conjugate Load Matching in the dividing network enables the speaker to present a flat,
resistive load to the amplifier. The impedance is set at 4 ohms, resulting in a doubling of
effective sensitivity and therefore of output level, over a conventional nominal 8 ohm load,
without any need for a more powerful amplifier.
An optional head cover is provided.
What makes KEF Model 107 unique is the inclusion, as an integral part of the system, of
K-UBE. K-UBE acts as part of Model 107’s entirely new hybrid dividing network to
combine passive frequency division with active response shaping. This arrangement
maximises the system’s dynamic range with any given amplifier and, by providing
independent control over low- frequency balance, extension and 'Q', allows the user to
optimise the LF/MF balance to suit the speaker's room position and to select bass
performance characteristics appropriate to the programme material.
KEF Model 107 combines excellent dynamic range and power handling with unusually vivid
stereo imaging and a remarkable freedom from cabinet induced colourations. Its simple
elegance and flat resistive impedance make it both easy to house and to drive. Above all
Model 107 offers genuine bass extension flat to 20Hz whilst giving the user unprecedented
control over all important aspects of low-frequency performance.
1.1 GENERAL NOTES
Your new KEF Model 107 loudspeakers contain a number of significant innovations, chief
among which is the ability they give you, with K-UBE, to tailor the sound balance to your
room, and to select both bass extension and characteristic to suit the programme material
you choose and your listening preference.
Set-up is simple, but somewhat more critical than with most conventional loudspeakers.
Please take the time to read this manual carefully and follow the procedures for assembling
and connecting your Model 107.
Care taken over set-up will ensure their optimum performance and your listening pleasure.
One pair of KEF Model 107 is contained in four cartons:
2 cartons each containing 1 bass enclosure
1 carton containing 2 head covers
1 carton containing:
2 MF/HF head assemblies
1 K-UBE active equaliser
: 1 K-UBE power supply