Image Hifi - GÖBEL HIGH END

Test
Bending wave loudspeaker
Göbel Audio Detaille S and Detaille Sub
Setprice: 4170 Euro
by Cai Brockmann, photos: Rolf Winter
Did I miss something? Have you been in Africa?
26 image hifi 5/2005
Sometimes exotic just means Upper
Bavaria.
If you suspect an inhabitant of a
Hanseatic town, like I am, of not being
able to get along with certain bavarian
rituals after several years, there
might be a grain of truth. Be that as
it may: For image hifi, the specialist
journal for high fidelity exotics, I attend
to much more thrilling issues
than the self-adulation of some original
inhabitants or rhetorician.
It is about high-tech and hi-fi, about
traditional values and future prospects,
about Laptops and Lederhosen
- although without Lederhosen (in
fact without Laptop as well, but more
about this later on). It is about Göbel
Audio.
Close to Munich, amidst true rural
scenery, this start-up company produces
remarkable loudspeakers which
have nothing in common with conventional
speakers and which open
up new vistas concerning music reproduction.
Fittingly enough, the
boss is not an instituion on HighEnd
audio, but rather passes more for a
rookie. Oliver Göbel is only near
30, but looks back on some notable
achievements concerning hi-fi and
acoustic irradiation - true prospective
candidate of our favourite guild. If
you wonder why you haven’t heard of
Oliver Göbel so far, it might be due to
the fact, that you don’t have speaking
cabinet doors.

One of the projects, the Journeyman
Electrician was working on in the late
1990s, was about cabinets with invisible
loudspeakers, which he developed
at his late employer Siemens. Needless
to say, not just any loudspeakers behind
huge rustic rattan furniture booming
the living room. Quite the contrary:
the cabinet doors themselves become
the loudspeakers. They are activated by
NXT-technology (so-called “exciters”
on a certain surface). To correct the
messurement deficiencies, Siemens
offers a digital equalisation by DSP -
or a much more complex, all-passive
solution, entirely developed by Oliver
Göbel. And lo and behold: the sounding
furniture baffled the audience at
big furnishing houses, at the CeBit
and even at the Expo 2000.
But Oliver Göbel wanted more: bet-
Base work: high pass filter, level adjust, terminals and
cable routing are integrated inside the stand
ter sound, better clearity, more definition,
more HighEnd. In addition to
this, he always suspected an equalisation
by DSP, which, even worse, corrected
only the amplitude. Instead of
depending on digital control, he was
smart enough to focus on a few steps
before within the production chain,
in order to unveil the secret of perfect
sound: materials, assemblies, fabrication
and process control. However,
Siemens only wanted to promote the
much more primitive and cheaper digital
solution.
What had to come happend: Göbel
floated his own business. A decision
that displays courage, enthusiasm and
consequence. So it’s no surprise, that
he is very quickly able to present his
first result.
So let’s have a closer look at the De-
Test
Bending wave loudspeaker
taille S: an extremly wide spreading
bending wave loudspeaker with a rectangular
membrane of 20 x 27 centimeters,
which plays seven octaves - from
150 to 28,500 Hertz - absolutly clear.
In addition to this, a conventional subwoofer
tops the set off.
Let’s remain with the exotic: the
bending wave loudspeakers. Göbel
Audio doesn’t use the conventional
material for the alternating flexural
surface, they developed their completely
own, custom made membrane
material. The material structure as well
as the impulse and the damping parameters
are considered to be unique
in the world. It stands to reason, that
the proud developer doesn’t want to
give away all of the details. After all
he showed me the manufacture of a
membrane.
Made by Sitronic: the subwoofer can be perfectly integrated
into every hearing room. Two subs even better...
5/2005 image hifi 27

Test
Bending wave loudspeaker
The basic material consists of a “special
kind of tropical wood”, which is
ultra light and extremly solid. For the
use as bending wave loudspeaker, the
compression strength and the stability
of the wood fibres (the lignin content
- something I didn’t know) are as important
as the direction of the fibres.
Thin slabs of wood are being matched
in pairs and extensively damped on
both sides: the wood is being covered
with a very thin grounding and sealing,
followed by two layers of a gauzy
fibre glass cloth and a non-aging
epoxy resin, which is even being used
by the aircraft industry. This nine-layer
sandwich membrane is being merged
under high pressure to a stiff but nonresonating
bending wave panel of only
one and a half millimeter thickness. In
order to eliminate any resonances or
reflexions for sure, incisions with two
different angular dimensions are being
laser cut on the edge of the membrane
and then being filled up again with
silicone. The only thing Göbel keeps
secret is the back of a fully functional
Lasershow: incisions
with different angular
dimensions, filled up
with silicone in order
to prevent resonances
28 image hifi 5/2005
Detaille S. Not a big surprise: It is the
exact positioning of the exciters as well
as the sophisticated damping, which
consists of aluminium, foam rubber,
rubber and wood that is responsible
for the sound quality.
Although it is the exact opposite,
with those incisions on the edge, the
membrane looks a bit like a workpiece
made from a raw natural material,
which has been sewed with a huge
needle. With a little bit of imagination
one could think the membrane
has been cut out of a nomadic people’s
tent in Africa.
The surface membrane has a rearside
dispersion of 4000 Hertz. The back
is covered with acoustic tissue and
the front has aluminium clampings
around the edge, which are mounted
on two elegantly curved aluminium
profiles. With the same hip swing, two
main pillars lead to the stand. There
you’ll find a directly soldered high pass
filter and a tuned circuit to protect
the Detaille S against dangerous bass
fragments and to linearise the level.
The stand and the pillars, which are
being lacquered three times, are made
of a high-strength and extremly nonresonant
polyurethane foam. In terms
of color as well as due to it’s discreetly
curved body, the active subwoofer goes
perfectly with the Detaille S anyway.
As far as the technology is concerned -
dynamic drivers, massive body, deeply
tuned bass reflex system, fully adjustable
180 Watt amp - the subwoofer
doesn’t break new grounds. Still it
fits perfectly into what comes “from
above”. It is really doing a very good
job, which means nothing less than a
big recommendation.
In fact, why a conventional subwoofer?
- Well, Göbel’s bending wave
loudspeakers emit the sound above the
coincedence frequency of 600 Hertz
as a wonderfully “chaoticly spreading”
Components of the test systems
CD player: Dyna Station 2
SACD player: Marantz SA8400
universal player: Linn Unidisk 1.1
turntable: Well Tempered Reference
phono sysetem: Denon DL-103
phono preamp: EAR 834P, Exposure XXVI
ubertrager: A23
preamp: Shindo Monbrison
Linn Exotik
power amp: Linn C2200
integrated amp: Einstein The Absolute
Tune, T+A V10
cables: A23, Eichmann, Göbel
Audio, HMS, Mogami,
Ortofon, Shindo
accessories: Dynatos D.T.S. 390,
Ensemble Honeyplate,
Finite Elemente Pagode
and Ceraballs, Stillpoints,
Sun power strip

surface into the room. Below this freuqency,
they work increasingly as normal
piston loudspeakers. Therefore, a
conventional subwoofer is alright. And
you’ll need the subwoofer.
By the way: A set of Detaille loudspeakers
includes not only the hardware,
but also the inventor’s applied
know-how - free home delivery. The
setprice is a real all-inclusive deal,
which means it is for a perfectly calibrated
system at the customer’s hearing
room. An outstanding service, which
guarantees the best possible sound in
everyone’s hut.
You should calculate two or three
hours until a skilled technician from
Göbel Audio has determined the ideal
position for the Detaille S in your living
room, adjusted the level and the phase
of the subwoofer and transformed a
pot coffee into empty.
Of course, Mr. Göbel himself comes
to my house with his computer, measuring
microphone and other stuff, he
needs for his acoustic measurement.
No Lederhosen, okay, but no Laptop,
Mr. Göbel? - Something like more
power, better measurement, he voices
under his breath. I don’t care. I have
to carry neither the computer nor the
monitor...
After this “home visit”, the perfect inphase
and isocronic dispersion, as well
as the low resonance level of the system
exemplify perfect HighEnd harmony.
Absolutely astonishing is the crystal
clear and completely detached sound
characteristic of the Detaille S, which
shows without any hardness, loosely
and very clearly, what electronics and
cables (recommendation: Göbel’s own
cables) are capable of.
Of course, the amplifier has to be
powerful to control the very brisk and
in terms of impedance linear, but not
very efficient Detaille S. From about
100 Watt on, you are you on a safe side,
the sound becomes more body.
Detaille S + Sub could subtly but insistently
persuade fans of raw dynamic
attacks that acoustic music, brilliantly
produced pop or sophisticated electronica
are superior to rough Rock ‘n’
Roll.
Another outstanding feature is the
fantastic phase locked sound dispersion
of 180 degree, what supports the
dipol characteristic of the Detaille S:
The living room is being acoustically
and athmospherically flooded; the
smallest details become three-dimensional
- and stay on the particular position,
even if you leave the (already very
generous) “sweet spot”. An experience
for a true gourmet.
translated by Mark Walter
Test
Bending wave loudspeaker
5/2005 image hifi 29