KEF 209 Brochure

VISIONARY

Quality. Honesty. Innovation.

These qualities are why KEF commands such

respect among audiophiles. Ever since the

pioneering engineer Raymond Cooke founded

the company in 1961, KEF innovation has

helped to shape the evolution of modern

audio technologies.

His vision holds true today, in a brand driven by

original thinking and engineering integrity rather

than passing fads. No other manufacturer

can claim such a distinguished design pedigree,

from revolutionary driver concepts and the use of

radically new materials to a host of patented

refinements that transform the listening experience.

But making great loudspeakers is an art as much as

a science, and these innovations are all designed to

enrich that emotional experience by achieving the

clearest, purest sound.

Welcome to the world of KEF Reference Series.

THE STORY. . .

Photograph : Martyn Goddard. Courtesy Sunday Telegraph Colour Supplement.

In a world where everything is relative,

KEF Reference Series has always stood for

absolute standards.

The design approach has always been consistent:

to give some of the world’s most gifted acoustics

engineers the freedom to set a new performance

yardstick. After years of research and painstaking

development, the resulting conceptual

breakthroughs are built into prototypes that are as

close to perfect as possible.

After exhaustive measurements and listening tests

using different media under anechoic conditions and

in real rooms, each prototype is fine-tuned to

become ‘the reference’ to which every production

version must conform. Each speaker is then

hand-assembled by a skilled craftsman who matches

the performance of each driver to within 0.5dB.

It’s a process that takes time, skill and patience – but

it creates a range of loudspeakers that continue to

redefine the boundaries of sonic performance.

Meet the new benchmark.

HERITAGE

As KEF’s signature technology, the Uni-Q concept is

renowned for its uncannily natural sound and stable

imaging. In the Uni-Q configuration the tweeter is

mounted at the centre of the midrange cone so that

their acoustic centres are at the same point in space.

The outputs from the two units are thereby time

aligned and will sum perfectly for all listening

positions. The profile of the midrange cone controls

the directivity of both drive units so it acts not only

as a superior midrange radiator but also as the

optimum waveguide for the upper registers.

Now, after nearly two decades of continuous

development and a host of new patented

refinements, every component of this uniquely

advanced driver array has been redesigned to

achieve a quantum leap in performance.

The tweeter now has a vented motor system with

three rare earth magnets, and a unique braced dome.

The midrange unit has a low profile surround that

eliminates edge diffraction effects. These innovations

take Uni-Q performance to a new level.

Dispersion is wider still. Power response is even

more uniform. Tonal balance is more realistic across

both direct and reverberant fields. Multi-channel

imagery is clearer and more accurate than ever.

UNI-Q

®

PRECISION

Interesting things can happen when you push

beyond normal limits.

Head of Acoustics, Engineer, Dr.Andrew Watson

and the Reference Series design team set

out to build the most natural sounding

loudspeakers possible, irrespective of cost or

practical constraints.

The ‘Austin’ concept was the result – a technological

tour de force standing two metres high and weighing

more than 120 kilos apiece. Awesome is the only

word to describe how they sound.

The project became the technology testbed for the

new Reference Series. The two-piece compound

titanium tweeter dome whose pistonic motion

reproduces higher frequencies with such effortless

clarity; the new shallower midrange cone that

disperses the soundfield so broadly; the elegant

fourth-order crossovers, computer-optimised for

superior driver integration.

GROUNDBREAKING

Big ideas. Big sound. Big benefits.

AUSTIN

The new Reference Series responds even more

musically than its acclaimed predecessors by combining

design innovation with an exceptionally rigorous

approach to the specification of each component.

The crossovers, for example, are computer-modelled

to optimise amplitude and phase behaviour for the

smoothest possible integration.

the crossover boards decoupled to isolate them

from cabinet wall vibration and to stabilise them

against the high acoustic pressures inside, but the

multi-board construction also eliminates crosstalk

between the different sections.

High saturation iron powder core inductors are

selected for bass sections, where large inductance

values and low resistance are required; air cored

inductors are used elsewhere for their superior

linearity. Similarly, there are high quality bipolar

capacitors for low frequencies, and very low loss

polypropylene capacitors for the upper ranges.

High power rated wire-wound resistors are

specified throughout to assure minimal

compression and maximum linearity.

Not only are

INNOVATION

Hidden away as they are, as much care has gone

into the design of these aspects as those that are

visible. And the difference is plain to hear.

CROSSOVER

KEF Reference Series cabinets are works of art in

themselves, quite apart from all the high-end

technology they enclose.

The sumptuous choice of finishes, from the sheer

depth of the high gloss veneers and piano black to

the seductively silky satin finishes, do admittedly

hint at the uncompromised build quality.

What’s so special about these curved section

cabinets is how they perform – and why.

Precision engineered from beech ply, they’re

designed to eliminate every unwanted vibration

that would otherwise muddy the sound.

Massive internal bracing tailors the volume of each

enclosure to the exact parameters of its drive

unit, and mechanical and acoustic damping ensures

an inert structure that never colours the

inherently natural sound.

With independent driver loading and KEF’s proven

decoupling techniques, these are cabinets that do

nothing to mask the performance of the

components inside.

KEF’s high-end Uni-Q loudspeakers have had the

benefit of a dedicated lower midrange driver since

1989. By allowing each section of the frequency

range to be optimised for its specific role,

this configuration creates much smoother

transitions between the Uni-Q array and the bass

drivers. The integration is so precise that it’s

virtually impossible to hear that the sound is being

generated by a four-way configuration.

The resulting acoustic performance is markedly

superior, with the delicacy and precise imaging of

KEF Uni-Q perfectly complemented by the scale

and impact of a truly assertive bass section.

The 250mm (10in.) lower midrange driver of the

Model 207/2 has a distinctive chrome ‘phase plug’

at its centre to optimise its acoustic response.

A lightweight neodymium magnet assembly allows

the unit to be mechanically decoupled from the

cabinet to minimise the transmission of vibration

and to ensure that its sonic purity matches that of

the bass and Uni-Q sections.

No panel resonance. No standing waves.

No stray reflections. No box colorations.

Just pure, sweet sound.

SOUND THINKING

DEDICATED LOWER MIDRANGE

For all the technological innovation inside the new

Reference Series, the personal commitment to

build quality remains true to the uncompromised

standards originally set by Raymond Cooke.

The exceptional finish speaks for itself, but the same

obsessive attention to detail applies to the parts you

never see. KEF’s own graded OFC (Oxygen Free

Copper) cable is soldered by hand and the drivers

are magnetically shielded to prevent interference

with your TV. Signal transmission is optimised on

all models by having three pairs of fully shrouded

gold plated WBT

or tri-amplification.

Naturally, performance can be fine-tuned for

your room acoustics. The KEF Uni Balance

feature allows you to adjust bass output to

compensate for the proximity of the

loudspeakers to the walls. At the high frequency

end, a four-position adjustment gives ample

‘brightness’ control to compensate for the

room’s sound absorption characteristics.

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terminals to allow tri-wiring

ATTENTION TO DETAIL

The Reference concept is all about pleasure

that lasts. So when you open the polished

wooden case that comes with your loudspeakers,

you’ll find a certificate of authenticity signed by the

craftsman who made them, along with your

Reference Series manual and all the accessories

you’re ever likely to need

.

PRIDE