Owner's Manual

Uni-Q
KEF developed the very rst Uni-Q driver in 1988 and has been progressively and relentlessly rened ever since. However, the reason why this
signature innovation out-performs other approaches remains constant: placing the tweeter in the acoustic centre of the midrange cone brings
the acoustic ideal of a single point source closer to realisation. The new Uni-Q array found on the R Series represents a leap forward in sound
quality, hailing a new, 12th generation of this already iconic design.
For starters, Uni-Q’s midrange motor system has been completely redesigned using KEF’s in-house simulation and analysis tools as well as
decades of experience. The motor is responsible for converting the audio signal from an electrical voltage to a mechanical force. Ideally it does
this without any loss and without introducing any distortion. For a midrange driver, signicant distortion can be generated due to modulation
of the voice coil inductance. The motor in the new R Series has a shaped and undercut pole, and symmetrical aluminium demodulation rings,
which combine to signicantly reduce the inductance in the lower midrange so there is less variation as the voice coil moves.
Another of the challenges faced when constructing a combination driver array like Uni-Q, is managing the minute gaps that separate the
constituent parts. There is a narrow channel between the moving midrange voice coil and the static start of the tweeter waveguide.
As air passes over this it creates resonances like blowing over the top of a bottle.
Obviously, this gap is necessary to allow the midrange cone and voice coil to move, so KEF has improved the performance by opening up a
cavity behind the drive units and then introducing damping material into the space created. This absorbs resonances and helps deliver more
precise, purer treble performance thanks to reduced colouration.
Shadow Flare
Derived directly from the Reference Series, the Shadow Flare is an innovative method of reducing harmful cabinet diffraction and one that
allows the wonderful Uni-Q to work at its highest level.
Shadow Flare is more than just a trim ring. It is a precision designed surface that extends the waveguide effect of Uni-Q. The tweeter no longer
has line of sight of the cabinet edges, creating a ‘shadow region’ at the points where the potential for diffraction is highest, minimising the
acoustic impact to negligible levels.
The result is improved clarity, particularly when it comes to the subtle nuances of plucked strings and other percussive sounds.
Bass drivers
To maximise bass performance in the new R Series, the dedicated low-frequency
drivers are built using a two-part structure, where a shallow concave aluminium
skin sits atop a paper cone. This stiffness combined with the cone’s unique
geometry reduces additional resonances and delivers the pistonic movement that
makes these drivers time so well.
The new drivers also benet from a completely redesigned magnet system that
creates a more even magnetic eld, and a design of suspension that reduces
harmonic distortion for a cleaner, more precise sound.
The result is tight, agile bass that digs out all the soul and punch available in the low end.
Cabinet bracing
All the cabinets in the new R Series benet from Constrained Layer Damping bracing. Originally
developed for the multiple award-winning LS50, this system utilises internal braces joined to the
panels by a lossy interface rather than being adhered to it rigidly. This approach is highly effective at
dissipating unwanted vibrations.
A new internal bracing layout works alongside Constrained Layer Damping to create an incredibly
inert platform from which the drive units can work their magic, enabling the R Series to deliver music
as it is supposed to sound, without any unwanted extras.
Shadow areUni-Q