Buying
replacement drivers
February
11, 2015
Roy,
I
have a pair of Audioplan Kontrast III SI speakers, and I know that you have had them
before as well. I have had them for many years now and I never wanted for anything else.
Recently, I accidentally blew one of the midrange drivers, so I'm looking for a
replacement. I thought I better check with Audioplan, but their replies have been erratic.
I was wondering if I can just buy the Audax drivers from other suppliers. I was told by
Thomas Kuhn of Audioplan that the drivers are slightly modified to their specs, but I
doubt that very much. Are you able to advise me what I should do? Wait for Audioplan or
just buy them from a third-party supplier? By the way, Audioplan quoted me twice as much
as the third-party vendor.
Ng
Chee Kia
The
Kontrast III SI is a great speaker that works particularly well in smaller rooms, and it
is worth ensuring that you keep it in the best possible condition. The idea of
manufacturers specifying driver modifications is widely misunderstood. The assumption
tends to be that such a modification would be to the cone or some other physical
parameter/part of the driver. This is occasionally so, but much more often the
modification is designed specifically to affect the electrical or mechanical performance
of the driver (its fundamental resonance, Q, impedance, bandwidth or sensitivity). This is
done so that the drivers dovetail more accurately/easily with the system requirements
established by the crossover, enclosed air volume and bass loading. In other words, the
thing it impacts directly is the integration of the loudspeaker as a whole, its ability to
sound like a single, seamless whole -- the very thing that makes the Kontrast III SI such
a special speaker. Also consider that Audioplan buy their modified drivers in quite small
numbers compared to general production, a factor which will make them considerably more
expensive, helping explain the price that you have been quoted.
I would strongly recommend that you purchase the driver from Audioplan and
maintain the speaker in its original form. Buying a cheap unit that looks the same might
seem like a bargain, but it is a false economy as it will seriously undermine the
performance of not just the speaker you fit it to but the pair matching as well.
One
word of caution: Audioplan use their own, very heavy speaker cable internally. If you have
any doubts about your soldering skills, have a qualified technician fit the driver, as
clumsy soldering can easily overheat and damage or destroy the voice coil on your nice new
(and expensive) drive unit. -Roy Gregory
From
Sophia 2 to Sasha W/P?
February
5, 2015
Marc,
Where
do I go from the Wilson Sophia 2? I just love these speakers! Can I go to the first Sasha
W/P and get that natural tonal balance, or will it get a bit tipped up? Sounds like they
are certainly more dynamic, but maybe more present in the upper octaves too. My room is
17' x 21'.
Bill
Barotti
The
Wilson Sasha W/P will be an upgrade for you, as it's a later and greater Wilson speaker
from your Sophia 2s. However, the better choice, in my opinion, would be the Sasha W/P
Series 2, and here's why: It's a much more refined version of the speaker with two of the
design cornerstones of Wilson Audio's latest speakers. It uses Wilson Audio's Convergent
Synergy silk-dome tweeter, and there are now 20 group-delay positions for the
midrange/tweeter module, instead of four with the original Sasha, improving the speaker's
time-domain performance. Yes, you'll have to pay more for the newest Sasha than a used
pair of the original speakers, but you'll also have these speakers much longer, because
you'll be buying Wilson Audio's latest technology, and that may save you money in the long
run. Your room is about perfect for them too. -Marc Mickelson
Cooler
amp for CS3.7?
February
1, 2015
Marc,
You
have answered a couple of questions for me in the past to great effect, so I hope you
don’t mind another one. This one concerns the running temperature of the my amp. My
current amp is an Audio Research Reference 150 (into Thiel
CS3.7s). I previously had a Reference 110, but I have found that the KT120s in the
'150 run quite a bit hotter than the Reference 110 ever did. My room (5m long x 4m wide x
3m high) gets quite warm now (in a New Zealand summer, unpleasantly so). But I do love
what the Referece 150 brings to the party.
I’m
wondering if the Reference 75 (with half the number of output tubes) would run any cooler
and therefore would solve my issues. I listen at moderate volumes to a diet of jazz and
classical music. No ear-bleeding levels (domestic harmony dictates).This then raises
another question -- would the Reference 75 have enough current to drive the '3.7’s? I
can get air conditioning installed in the room, but I was wondering if the Reference 75 is
a viable alternative with little sonic difference.
Kevin
O’Connor
You
pretty much answer your own question. Half the tubes will mean much less heat, as they,
along with the fans that cool them, are the major sources of heat from your Reference 150.
An important question, as you note, is if half the power and reduced current -- 75Wpc for
the Reference 75 versus 150Wpc for the Reference 150 -- will drive your Thiel speakers to
acceptable levels. There is an answer for that too: Just drop a match quad of KT150s into
the Reference 75, as Carl Marchisotto of Nola has done, and you'll get 20%
more power -- 90Wpc. You might also get a little extra heat, as the KT150s are larger
tubes, but it will be negligible compared to the heat you're getting from your Reference
150 now. You might also gain some sonic purity, as the Reference 75 has fewer parts than
the Reference 150, and the KT150s seem to add some magic to the sound of the amp. I have
to say that the Reference 75 with KT150s intrigues me for this reason.
By
the way, your Thiel CS3.7 speakers are likely the last of the breed. While the Thiel name
continues, the pillars of Jim Thiel's design philosophy -- first-order crossovers, time
and phase alignment -- are no more under the Thiel name. Enjoy your speakers. We will
likely never see their equal, especially with Jim Thiel-designed drivers. -Marc
Mickelson
