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Listening Room
32 ULTRA HIGH FIDELITY Magazine
quite sound the same. Getting a seamless
blend — already a challenge in a
two-channel system — requires much
more than just buying all your speakers
from the same manufacturer.
Where do you put that centre
speaker? If you’re using a front projection
system, or even a plasma screen,
there’s probably lots of space under
the screen. With a rear projection TV
it’s not as easy, because the TV almost
certainly goes all the way down to the
floor. And with a cathode ray tube, it’s
even tougher. The magnetic field about
the woofer(s) can cause significant color
shifts in the picture. This is true even of
speakers that are advertised as shielded,
since shielding is never absolute.
Most systems have centre speakers
that are placed close to the floor, and
tilted up. But in a small or medium-sized
room, that means placing the speaker
in front of the TV, and therefore much
closer to you than the other speakers.
In many cases the speaker will be firing
into a sofa or an upholstered chair. Don’t
be surprised if the timbre of a sound
changes as it is panned across the sound
stage.
A better place for the speaker is
atop the TV, probably angled ever so
slightly down. This is not easy to pull
off, since modern TVs don’t have flat
tops. And how good an idea is it to put a
loudspeaker right on a highly resonant
plastic box? Elsewhere in this issue you’ll
find our own solution to this problem:
a stabilized, acoustically-isolated platform.
We used such a platform for all
of the speakers in this set of reviews,
including the largest and heaviest, the
30 kg Thiel MCS1.
But before we actually inserted these
centre speakers into our Kappa (home
theatre) system, we put them through
a brutal test in the refined acoustical
environment of our Alpha system.
How well could these speakers reproduce
the human voice? We decided to
find out. The three usual reviewers
recorded their own voices, reading a
favorite bit of text, with a high quality
condenser microphone. That would
allow us to do something we normally
cannot do: compare a reproduced sound
with the live original. We anticipated
that not all the speakers would necessarily
do well on this test. A speaker
that flunked it would never get to see
our Kappa system.
That test would be carried on in
our Alpha listening room, with its
remarkable acoustics. Also in the Alpha
room, we listened to a mono recording,
Linn’s excellent pressing of Beethoven’s
Fifth, with Carlos Kleiber conducting
the Concertgebouw Orchestra. And
we added one more selection, Bird on
a Wire from Jennifer Warnes’ Famous
Blue Raincoat.
With that evaluation done, we moved
each of the speakers into our Kappa
room, to give each of them a shot at
reproducing the dialog and other central
material from three films:
a) Chapters 9 and 10 of the director’s
cut version of Amadeus, which includes
a segment of Abduction from the Seraglio
and the scene in which the Emperor
complains that there are “too many
notes.”
b) Chapter 5 of the second Harry
Potter film, in which Harry travels by
“flue powder” and runs into Hagrid and
Hermione.
c) Chapter 26 of The Fifth Element,
featuring the aria by the Diva Plavalaguna
and the simultaneous one-sided
battle between Leeloo and the piglike
Mangalores.
Not all of the speakers have equal
efficiency, needless to say, but our Moon
Attraction processor can compensate
for this automatically. As we brought
in each centre speaker, we plugged an
omnidirectional microphone into the
Attraction, placed at viewing position,
and pushed the Auto Setup button. It put
bursts of pink noise into each speaker,
one after the other, and adjusted each
speaker for equal volume. With a series
of clicks, the Attraction checked that all
of the speakers were in phase (they were).
Last but not least, it adjusted the delay
on the surround speakers so that sounds
from all five speakers reached us at the
same time.
An option on many surround sound
processors, including our Moon Attraction,
is to roll off the low-frequency
response to any given speaker and send
the bass information to the subwoofer
instead. In our Kappa system we have
done that only with the surround speakers,
which are quite small. We did not do
it with any of these six centre speakers. If
any of them got into trouble on difficult
passages…well, so be it. A similar feature
exists on other processors, and with half
the speakers we reviewed it should be
used.
We hoped to position all the speakers
the same way in our Kappa system, but
we were initially not certain this could
be done. The ideal place, we determined,
would be atop our Hitachi rear projection
TV. To put the speakers there, we
designed our own isolating platform
(you can read how to build your own
platform — see Placing the Centre Speaker
in this issue). Two of the speakers, however,
were so large and heavy that we
expected to position them in front of the
TV, just below the screen Indeed one of
them, the Thiel MCS1, came with its
own optional, very heavy steel bolt-on
stand. We were happy to discover that
our platform was so effective it could
take the largest speakers without compromising
stability or performance.
If you’ve read the extensive report
in UHF No. 65 on the construction
of our Kappa system, you’ll know that
we had not yet chosen a centre speaker.
Our intent was to adopt one of the test
speakers, assuming at least one of them
would turn out to be of reference quality.
The one we would acquire would
not necessarily be the “winner” of the
comparison. The chosen speaker would
have to do outstandingly well on the
tests to be sure, but it would also need
to blend well with our main speakers, the
Energy Reference Connoisseur (which
we have owned since 1984). Failure to
do so would of course not be considered
a shortcoming.
Incidentally, we invited Energy to
submit one of its centre speakers for
this series. The company declined, as
did its other division, Mirage.
We would have loved to have
included a dozen or more speakers in
this series, but we quickly saw that this
was way beyond our technical means, to
say nothing of the space in either our
headquarters or the magazine. Consider
this to be the first installment of what
will turn out to be an ongoing tournament.
And let the jousts begin!