| The Solid Tech Rack
of Silence, Disc of Silence and Feet of
Silence Isolation Devices |
|
A Stand for the Mass-less! |
|
Greg Petan |
|
December 2003 |
Specifications
Rack of Silence - $1470 to $1899
Feet of Silence - $300 (set of 3) $400 (set of 4)
Disc of Silence - $190 (set of 3) $250 (set of 4)
Address:
Solid Tech
Klågerupsvägen 357
S-212 36 Malmö
SWEDEN
Vox: + 46 - 40 491 352
Fax: + 46 - 40 491 352
Email: info@solid-tech.net
Website:www.solid-tech.net
U.S. Distributor:
Audiophile Systems, Ltd.
8709 Castle Park Drive
Indianapolis, IN 46256
Toll Free Consumer Information Line: 1-888-272-2658
Main Phone Number: 317-841-4100
Fax: 317-841-4107
Email: aslinfo@aslgroup.com

Some things just look too cool to ignore.
So it was in Las Vegas at the 2003 Consumer
Electronics Show, when I saw Solid Tech’s “Rack of
Silence” in the Zanden Audio/Ascendo speaker room. I
shot right to the “I have got to have that!” place in
my psyche. And once that’s activated, a chain of
events of which I am quite powerless over, is set into
motion, always resulting in a much lighter checking
account balance.
The timing of this discovery couldn’t have been
better. I needed a new home for my components and have
spent the better part of a year checking out the
offerings of many worthy manufacturers. As my system
is centrally located out in the vast open space of my
loft, I wanted something with visual impact and a bit
out of the ordinary. My search left me rather
surprised at how few designers of audio furniture take
even the slightest aesthetic risk, how little emphasis
they place on setting themselves apart from the
throngs of rather ho-hum designs. After repeated
unsuccessful attempts to locate the stands
manufacturer at the show, I put my checkbook away and
waited ’til after the show to get the ball rolling.
Back in New York, I got a hold of the designer, Mr.
Bjorn Ohlson, founder of Solid Tech, and arranged for
the delivery of the Rack of Silence Amplifier stand.
Upon reflection, I was a little wary of the sonic
effect the full stand would have on my acutely
balanced system. As a result, I decided to start with
the amplifier stand and take it from there. Built to
the dimensions of my Jeff Rowland Model 302 amplifier,
the amplifier stand arrived and was immediately put to
the test. Keeping in mind that the Rowland Model 302
was designed with anti-resonance as a priority, I was
shocked at the over all sonic improvement that the
Rack of Silence imparted. With my apprehension
quelled, I immediately called Bjorn and arranged to
review the full Rack of Silence for my components.
The Rack of Silence arrived partially assembled and
within an hour, full assembly was complete. The fit
and finish of the Rack of Silence is first rate. The
combination of cherry stained beech wood shelving
struts (black is an option) and the extruded aluminum
pillars are gorgeous. While the stand appears massive,
it is relatively lightweight though extremely rigid—a
natural characteristic of the extruded aluminum
pillars. While some manufacturers swear by mass as the
cure for resonance control, the Rack of Silence uses
spring suspension for the X-brace that acts as a
shelf. At least two of the X-brace shelves must be
fixed to the pillars at a distance of at least half
the length of the pillars in order to provide rigidity
to the structure of the stand, allowing the remaining
shelves to remain sprung. Large-diameter ball
bearings, used as an additional level of resonance
control, sit in a groove carved out of the top of the
X-shelf struts. The stand itself sits on the
spring-suspended “ Discs of Silence.”

There are two additional levels of support available
to bolster the Rack of Silence: the “ Feet of Silence”
and the above-mentioned “Discs of Silence”. The Disc
of Silence is round with an open center. Springs that
attach around the perimeter of the disc hold a rod
with a flat cork-covered plastic cap in place at the
center, creating a kind of trampoline.
The Feet of Silence are more complex. A
high gloss polished or black
anodized aluminum housing holds a floating bearing
held in place by a sub-chassis that in turn is
suspended by small gauge and
UV resistant rubber bands. As the weight of the
component falls on the bearing, it compresses the
suspended sub-chassis held by the rubber bands. Each
of these devices worked as advertised and contributed
to the fine sound that the Rack of Silence made
possible. Finally, each X brace shelf can be fixed to
the pillars or suspended by springs as an additional
form of isolation. In my stand, the top and bottom
shelf are fixed, while the two middle braces remain
suspended.
Bjorn Ohlson explains the
Rack of Silence concept:
“Since the most degrading vibrations/resonances are
those with low frequency and high amplitude, our aim
has been that the load carrying structure should have
a natural high resonance frequency and in a
corresponding way, low amplitude at resonance(less
energy storage and a quick decay). Since it is the
form, size and stiffness of the structure that
determines its natural resonance frequency, we have
chosen to avoid the large physical structures of shelf
planes, and replaced them with struts that have a
favorable stiffness-to-weight ratio for their size.
The resonance frequency of the carrying structure has
thus been shifted considerably higher up, resulting in
lowered amplitude.
However, no matter what materials or concepts that the
rack consists of, it is our firm belief that in order
to obtain optimal performance, one must include
effective isolation in the set up of an audio system.
Any technique that does not provide isolation of
external vibrations will only vary the amount of
resonant stimulation added to the components
concerned. It cannot reduce the level of baseline
vibrations in the floor.
In order to achieve an effective isolation and
uncolored reproduction, there must be a freedom of
movement in all planes, and the resonance frequency of
the isolation material must be outside of the
20-20,000Hz audio spectrum. Our different isolation
systems like the Feet and Disc of Silence as well as
the shelf suspension system have at normal load a
resonance frequency well below 3 Hz. This means that
isolation starts at approximately 4Hz, which is
clearly outside the influence of the audio range. It
should be mentioned that 100% effective isolation does
not exist. For that reason, our system permits and
facilitates isolation in up to three steps. Namely,
with permanently mounted Discs of Silence at the floor
end of the corner pillars, shelf suspension and/or
Disc & Feet of Silence for the isolation as close as
possible to the apparatus.”
Listening
With all my components arranged on the stand, the
first thing I noticed was that everything bounced and
jiggled around when the stand was nudged! This can be
a bit unsettling when, for your whole life as an
audiophile, you have dealt with spiked components and
massive stands. My concerns melted away like a June
snow when I pushed “play” and the digits were
converted to sound. In broad terms, the Rack of
Silence was able to bring the whole of the performance
forward in space without any sharpening or brightening
of the upper frequencies. There appeared to be more
meat on the bones, as information came through in a
more coherent and organized fashion. All of the
smearing of detail that went un-noticed before became
apparent when contrasted with the new presentation.
What had been natural sounding system to begin with,
improved in ease and refinement, allowing for higher
listening levels without the penalty of harshness or
hyper-delineation. With acoustic signatures of all
pedigrees, be they conjured up in a studio or the real
space of a concert hall, the Rack of Silence carved an
additional layer of brick out from behind my speakers
creating a broader, deeper canvas on which to render
whatever was on the recording. Margo Timmons’ aching
melancholy on track 1, Something More from the Cowboy
Junkies’ “Lay It Down” (GEFD24952) occupied my room
with a greater degree of presence than ever before.
The Rack of Silence had an immediately recognizable
effect on the dynamics of my system. Using Satriani’s
“Devil’s Slide” off Engines of Creation (EK67860) as
an example, The Rack of Silence added a degree of
dynamic slam that kicked down the doors with
S.W.A.T.-like aggression and absolutely ransacked my
loft. My system sounded freer and less constrained.
Micro dynamics were improved as well, becoming lighter
and less encumbered. Tommy Flannigan’s playing on Sea
Changes (ECD2219) sounded more fluid, graceful and
nuanced. Josh Groban’s vocals on You’re Still You from
his self-titled debut recording (WMG 48154-2) were
rendered with an additional layer of detail, focus and
dynamic nuance. This admittedly fluffy material is
made palatable by the knowledge that Mr. Groban
possesses an extremely powerful voice that holds great
promise.
Conclusion
My experiences with isolation devices such as they
stands, shelves or spikes has never led to a
fulfilling long term relationship. While initially
impressing, most of these devices proved to create
some kind of shift in tonal balance, usually toward
brightness or a “leaning out” of harmonic textures. As
a result, I always ended up having to turn the volume
level down, robbing me of one of my few last vices. On
the other hand, combining squishy materials such as
sorbathane would dull the presentation and put me to
sleep in the process. The Rack of Silence, Disc of
Silence and Feet of Silence creates that perfect blend
of a lively dynamic range, and textural ease and
coherency, yielding a complete sonic image that is
just plain addictive. If you can put aside the years
of conditioning your belief system that mass is the
only way to go, then the Rack of Silence will reward
you with its many sonic benefits and set you apart
from the run of the mill, ho-hum designs your audio
buddies have settled for.
Post script: At
the end of the review process, I was able to try the
amplifier stand on the Gryphon Encore amplifier. The
results were much like that of the Rowland 302:
greater ease, deeper soundstage, increased focus and
dynamics. In other words, an across-the-board
improvement, with zero trade-off. This repeatable
result is a testament to the solid theory backing up a
great looking product.

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