ON TEST
54 Australian Hi-Fi http://www.avhub.com.auW
ant to know
a dirty
secret about
multi-chan-
nel home
theatre speaker
systems?
It’s that most of them are using the wrong
centre-channel speaker: one that’s not a tonal
match with the front-left and front-right
loudspeakers.
Let’s look at what’s required in a cen-
tre-channel speaker. In an ideal world, that
speaker would be a perfect acoustic match for
your main front left and right speakers. That
is, it must be not only be made by the same
manufacturer, but should also use exactly the
same drivers as your main front speakers. And
for best effect, it should actually have at least
one additional driver, meaning that if your
main speakers each have a bass/midrange
driver and a tweeter, your centre-channel
should have two bass/midrange drivers and atweeter. If each of your main front-channel
speakers has two bass/midrange drivers and a
tweeter, your centre channel should have four
bass/midrange drivers and a tweeter.
Why are so many drivers required in a cen-
tre-channel speaker? It’s all about tonal quali-
ty, frequency response and sound-staging.
Think about an ordinary stereo system.
You wouldn’t dream of using a three-way
fl oorstander as your left-channel speaker
and a small two-way bookshelf as your right
speaker, would you? You wouldn’t do it even
if they were made by the same manufacturer.
Yet if you look at the centre-channel
speaker that’s offered with most home theatre
systems, either included in a package, or
available as an option, you’ll most often see
that the front-left and front-right channel
speakers are completely different from the
centre-channel. The left and right-channel
speakers will usually have more drivers, and
often larger ones than the centre-channel.
Does this matter? You bet it does!In a stereo system, sounds that ‘appear’ to
come from exactly midway between the left
and right speakers are created by those speak-
ers... exactly what the stereo illusion is all
about. The better the left and right speakers
are matched, the better the illusion that the
sound is coming from an imaginary point
midway between them. And because both
speakers are matched, the tonal character of
the sound coming from midway between
the speakers will be the same as that coming
from either the left or the right speaker alone.
However, in a home theatre speaker sys-
tem, sounds that come from midway between
the left and channel speakers come not from
the front left and right speakers, but from the
centre-channel speaker. So if the centre-chan-
nel speaker is not identical to the left- and
right-channel speakers, the tonal character of
the centre-channel’s sound will be different.
Let’s look at an extreme example. Imagine
a system where the front-left and front-
right channel speakers are large, three-wayKRIX EPICENTRIX MK2
CENTRE-CHANNEL SPEAKER