January 2006
- Joe's
Loudspeaker Dream Comes True
Everything
started with our attendance in early December 2004 at the European
Triode Festival (ETF) in Langenargen at Lake Constance. This venue,
which was launched by tube & music enthusiasts years ago in
Denmark, is a wonderful opportunity to meet some of the most
outstanding designers of the DIY tube amplifier/ loudspeaker scene
from all around the world.
When
Joe and I drove to Langenargen to be part of the festival in
2004, one of Joe's friends, tube amp designer Thomas Mayer from
Germany, installed an incredible loudspeaker system into the big show
room at ETF in Langenargen. It looked like this:
Thomas'
system sounded extremely impressive and lively with its two Altec
15" 515B and two Altec 15" 416A (i.e. 16 ohms version) mid
bass / bass units and Technical Audio Devices' (TAD) TD4001 with TD
horns for the mids plus super tweeter for each channel; Joe was
hooked immediately and decided to go for his 'ultimate' dream
loudspeaker system. Thomas Mayer's system at ETF 2004 was great fun
to hear; despite some audible problems, it was obvious what
capabilities such a big LS system can have (on Saturday night
we had definitely the best disco sound ever in Langenargen).
By
the way, at ETF 2005, the same system, this time with fitting
electronics designed by Thomas, was a music lover's dream. I've never
heard music so real and lively and with such impact - this was an
awesome experience. (Hmm, the dimensions of such a system are too big
for my dedicated music room, but one day there will be a horn-loaded
system playing music for me, I think...)
After
the initial impression in 2004, Joe went on faith and decided to use
Thomas' system as a starting point. Since he had neither the space
nor the will to separate parts of his living room, a solution had to
be found. Starting from an infinite/open baffle speaker, one can
either go for a sealed enclosure (if one bends the baffle backwards)
or to a horn (bending the baffle forward).
One
of Joe's real strengths is his admirable capability of rapidly
realizing his projects. Once he had acquired 10 Altec bass chassis,
it took him about one year from the various prototypes to the
finished speakers. OK, he's fortunate enough that one of his friends,
Christian (www.zendron.at),
is a carpenter and Joe could get his advice, use his machinery and
part of his work space, but man, regarding this project no time was wasted.
It
is always said that horn loudspeakers have such an impressive bass,
but it is mostly second hand (you know, "I read it in a
magazine," "I have a friend who has a friend and he heard
it somewhere," and so on). But what is the truth? As Joe says
"the proof of the pudding is in the eating", so a prototype
horn was built.
(Photo
courtesy of Joe)
Hmm,
impressive but the phase problems between bass and midrange were
impressive too. So, Joe gave it a second try.
(Photo
courtesy of Joe)
Damn,
these horns were not only really good sounding and powerful, but
they also could fill up a 40m² living room.
So,
what can be done to preserve the power and the glory of these
monoliths yet wrap them up in some less demanding enclosure? After
some discussion with our friend David, Joe finally decided that
his 'ultimate' LS system would consist of the following: two Altec
515B and two Altec 15" 416A mid bass / bass units loaded with
wave guides developed by David, whose simulations indicated that this
arrangement would preserve the slam and ease, but with one octave
bass more, and allow a far more handsome appearance.
The
rest of the system should consist of the elliptical horn system for
the mid and treble sections Joe had used in his LS system (also
designed by David) driven by a TD4002Z driver (this is the Neodym
version of the TD4001 without horn adaptor), plus a JBL 2405 super
tweeter (16 ohm Alnico version) for each channel. Overall efficiency
of this system should be close to 100 dB (that's what all the great
low powered directly-heated SE triode amplifiers out there need to
really shine...).
To give you a glimpse of how it was done...
The
wave guides are made of concrete, so what you need for the speaker is...
(Photo
courtesy of Joe)
do
this...
(Photo
courtesy of Joe)
and
get that:
(Photo
courtesy of Joe)
If
you have two of these, simply sand, glue and polish them and you get
one wave guide front of the project. Have I said that you need 4
double-wave guides?
On Saturday, January 14, 2006 Christian, his friend Florian and I met at Joe's apartment to help him install his dream speakers (nicknamed Big Otto's after a famous Austrian wrestler "Big Otto Wanz," who in fact only weighs 160kg). Here are some pics of the installation process:
The
waveguides for the lower left and right speaker. We had to
glue
slotted grub screws into the ready drilled holes of each waveguide
to
later on be able to fix the 15" Altecs via their mounting
holes. To achieve
the
correct position of the grub screws for an easier assembling
process, we
put
the Altec chassis in place during the hardening process of the gluing.
|
Left cabinet skeleton; you can see the lower and upper chambers for each pair of Altec bass- / midbass-units as well as the space in between for the mid/treble horn section |
|
|
Ok, both Altecs are mounted in the lower left cabinet. Let's have a coffee break.. |
Right
cabinet skeleton with lower waveguide mounted - we're making progress; |
|
Upper
waveguide and bass chassis mounted. To lift up and fit the 85 kg |
Internal
view of the upper cabinet. Both |
Finally,
we finished the assembling work and here's the result plus a proud
owner Joe (on the left) and his friend Christian:
Aren't
they gorgeous. Sorry, I'm talking about the speakers...
It was definitely a great Saturday afternoon and I can't emphasize strongly enough, that I'm more than curious to listen to these babies. So, dear Joe, please finish the cabling, remaining cabinet work, active crossover and the remaining power amps as soon as possible, cause it's torture to wait much longer for a listening session.
I promise, I'll keep you informed about our first musical impressions...
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