A New Direction In
Sound
The "Q"
Factor - or why speakers sound different
in different rooms.
The Uni-Q principle,
developed by KEF engineers, realises the long-held ambition of loudspeaker
designerd to create the drive unit where all the sound radiates from a single
source.
"Q" is the
measure of a loudspeaker's directivity - how it bearns its sound towards the
listener. It is this factor which very largely determines how a loudspeaker
will sound in any given room.
When we listen to
live music we hear each instrument, a trumpet, say, from one discrete point in
space, together with a proportion of the sound reflected from around the hall
or room.
With reproduced
sound however, a single drive unit does not exist which peroduce the entire
audible spectrum. Most loudspeakers employ two or more drive units, separated
from each other. So now different parts of the trumpet come from two different
locations - and at slightly different times.
Because the
directivities of the two units do not match at crossover, the sound is
different at different listening positions. The tonal balance shifts as the
listener moves. Sit off-centre and the trumpet becomes muted, the singer
catches a cold. Listeners in different
posiitions, or indifferent roomscan heara coloure and out-of-focus soundstage.
Using
Neodymium-Iron-Born, a newly developed magnetic alloy which has ten times the
energy product of conventional ferrite, KEF designers have engineered a tweeter
assembly small enough to be located in the neck of the bass unit's cone,
precisely at the point where the sound
sources, the acoustic centres, of the two units coincide.
The direct and
refflected path-lengths from both units to the listener's ear are now the same.
Correct phase relationships ensure that high and low frequencies add up
correctly to produce the desired response.
With Uni-Q, not only
has KEF placed the woofer and tweeter on the same axis, their acoustic centres
are also in the same plane. The directivity of both units is identical. The
trumpet is back in one piece, unmuted and the singer's centrestage, in perfect
health.
The unification of
woofer and tweeter "Q" lies behind the revolutionary unit's name _the
KEF Uni-Q Driver. More accurate sound in more locations, and from more
listening positions is the keynote of Uni-Q.
