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A Brief Survey of Isolation Devices
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Aurios - Media Isolation
Bearings. Maker Vistek has wide-ranging expertise in solving
vibration induced problems on an industrial and
architectural scale. Since 1994, technologies developed by
Vistek and its affiliates have been utilized in structures
as varied as bridges, towers and clean rooms. Scaled down to
meet the needs of audio, Vistek make use of their knowledge
in the design of the Media Isolation Bearings. The very
latest Isotones version is shown.
Character: Exceptionally fast, open quality with very
good dynamics.
Pros: Relatively small, allowing their use under most
components. Almost limitless weight bearing capacity.
Cons: Price. Rack must be
level for optimum performance, but the new Isotones are less
sensitive to this issue than previous models. The enhanced level of detail
can prove overly analytical in some systems.
Dimensions: 2.0 - 2"D x 1"H 1.1 - 1.5”H x 1.5”D Pro – 1.75”H x 3”D
Black Diamond Racing –
Carbon fiber cones. Materials science has found its way into
the world of audio vibration devices. BDR cones are good
examples which are made from carbon fiber, a very strong and
very lightweight material. The company’s offerings include
cones, platforms, pucks and a record weight. We’ll confine our
survey to the cones. BDR offers two versions; Mark III and
Mark IV.
Character: The MkIII is a bit
warmer, the MkIV more extended.
Pros: Inexpensive. Short stature allows them to be use in
a wide range of applications. Low cost.
Cons: Short stature may not raise components high enough
to bypass existing feet.
Dimensions: .5” H x 1.5” D
Bright Star Audio: Bright
Star was the first to use sand as an isolation material for
audio equipment. Since then they’ve added pneumatic isolation
and constrained-layer bases to their line. The company offers
a wide range of products, in an array of sizes, depending on
the application.
Sand can
effectively store and dissipate vibrational energy. It has
been used in other industries where damping vibration is
needed.
Bright Star believes that mass loading the
component (adding weight) improves performance. Their Little
Rock products are heavy, damped pods designed to be placed on
top of components to damp the enclosure.
Pneumatic
isolation platforms can effective in some systems, but their
idiosyncrasies can be problematic. Leveling components with
unevenly distributed weight can be difficult to impossible
with single bladder designs. Multi bladder systems can
compensate, but as the bladders loose air the problems
returns. And all the designs I’ve tried air loose air pressure
over time. Pneumatic bladder designs require regular checks
for correct pressure.
Character: Can smooth peaks in a bright or edgy system
though some feel the sound is over damped.
Pros: Extra weight can help load the equipment stand.
Cons: Size may preclude their use if space is limited.
When filled, the sand boxes can be very heavy and will spill
if tipped.
Dimensions: Many sizes available
Price: About $200 to $500
Clear Audio - Magix
– Magnetic Isolation Pods. Such an interesting concept, that
of magnetic levitation and one that has been tried many times
over the years. The goal is to float a component on noting but
a magnetic field. Clearaudio Magix isolation pods have come as
close as any to achieving the goal.
What does a component sound like floating on air?
I’ve found the Magix enhance ambience, space and smoothness. I
note a reduction in grain and grit resulting in a very refined
and easy, almost soft quality. That said, some might miss the
attack, speed or detail found in the hard coupling feet,
roller and cones.
Character: Velvety smooth, airy.
Pros: Very good decoupling.
Cons: Expensive. Tall, thus preventing their use in many
applications. Expansive but somewhat diffused soundstage.
Notes: Each unit supports approximately 12 pounds. Divide
the weight of your component by twelve to determine the number
needed.
Dimensions: 4-1/4”Diameter x 3.3/4”H
Daruma IIIi – Ball bearing
isolators. Final Labs from Japan were the first to offer an
inexpensive ball bearing device. The Daruma IIIi works well in
many systems and as a result have enjoyed widespread
popularity.
A stainless steel ball bearing
separates top and bottom pucks made of aluminum. The aluminum
is rather soft (in comparison to the stainless ball) and will
gall under heavy loads. We do not recommend you not load the
Daruma IIIi with components over 30 pounds.
Character: Expect the speed, focus
and detail found in similar ball bearing devices.
Pros: Inexpensive.
Cons: Limited weight bearing capacity. Somewhat tedious
set up.
Dimensions: 1 – 3/4” Diameter x 2”H
DH Labs – The DH Labs
ceramic cones have become the most popular cones we offer.
Most of designers feel that (without resorting to metal) the harder
the material the better the performance. DH Labs has chosen
ceramic - the hardest material available (next to diamond).
Interestingly, the DH Labs cones are not at all hard or harsh
sounding. In fact, they range from what seems to be a neutral
balance (Jumbo) to slightly rich (Large). Overall the
Jumbo (they are the blunt-nosed cones in the picture) offers
the best performance for the price.
Character: Enhanced leading edge transient definition.
Pros: Lacks excessive brightness or stridency.
Cons: No major concerns.
Dimensions: Large – 1”H x 1.25”D, Jumbo – 1-3/8”H x
1-9/16”D, Super – 1.5”H x 1.5”D
Eraudio - Space Harmonizer
– Not really an isolation base in the strictest sense, we
should probably refer to the Eraudio as an equipment platform.
The manufacturer states that they use a set of resonant bars
of Siberian Cedar assembled into (a rather lightweight)
platform. It’s of laminated construction, similar to the way a
cutting board is made.
The manufacturer recommends that four viscoelastic
feet or steel cones (preferably their own design) be used
beneath the platform, one located at each corner. Best
results, according to Eraudio, are obtained when using the
Space Harmonizer under speakers. In all fairness to the
manufacturer, I was not able to test them effectively in that
scenario. There were simply too many obstacles to overcome
when the speakers were on carpet. Further the additional
height of the platform and cones beneath the speaker changed
the tonal balance of the speaker and made the results hard to
interpret. My listening tests employed source components and
electronics only.
I really did not find any significant effect when
using the Space Harmonizer. The platform did add a subtle glow
to the music, but it was indeed slight. The bases are rather
attractive, and most gear did look nice perched atop a Space
Harmonizer.
To be fair, the manufacturer does suggest that
speakers benefit most, but as mentioned previously, they
simply weren’t an option for me.
Character: Smooth, warm
Pros: Attractive.
Cons: Low perceived effect. The overall height is likely
to become an issue when the requisite cones are added. Sizes
are inappropriate for many U.S. components.
Dimensions: Small – 18.5”W x 11.5D x 1.5”H. Large – 24”W x
15”D x 1.5”H
First Impression Music - Isolation platform and
isolation stand. First Impression Music is respected for their
superb CDs and SACDs. Proprietor Winston Ma is a recording
engineer of great renown and a very dedicated audiophile. In
assembling his own system, he found himself dissatisfied with
much of the available offerings. This led him to design
several products on his own; interconnects and speaker cables,
an (outstanding) AC outlet and now three isolation products.
Many designers feel wood (particularly Maple)
offers a certain richness that enhancers harmonic structure.
It has become a popular material. Winston Ma felt that while
Maple (Ebony was his first choice, but far too expensive) was
a good basic material for a platform that on its own did not
fully address the issue of vibration and resonance control.
His experiments led him to marry the richness of Maple with
the speed of roller ball technology.
His roller bearing design is unique in regards to
the choice of materials. The load bearing pucks are brass,
coated with hardened white steel. A stainless steel or
tungsten carbide bearing is employed. The pucks are recessed
into the wood for intimate contact.
Two products are available. The Base consists of a
1.75” selected hard rock Maple platform resting on three
roller ball isolators and a lower MDF platform. The Stand uses
the same 1.75” Maple platform sited on four roller ball
isolators with a solid Maple frame support. The Stand is
recommended for speakers and other heavy components
(supporting up to 200 pounds), the base is designed more for
front-end gear. Though no maximum load specification is given
for the Base, we’d assume it would be 150 (three of the Iso
Bearings are employed, rather than the four used in the
stand).
The platforms have worked exceptionally well here.
In fact, I’d have to say they are one of if not the best
platforms I’ve tried. They offer the speed, attack and detail
we’ve come to expect from roller bearing technology, but
without the hard or metallic character some associate with
this technology. Maple alone can, in many systems, tend to
take things too far in the direction of warmth; roller bearing
devices may move too far the opposite direction. The marriage
of the two seems to be synergistic.
Character: Doesn’t seem to affect
tonality to any great degree, perhaps a touch of additional
warmth in the mids.
Pros: Balance of qualities – enhanced leading-edge
transients, improved resolution of low level detail.
Cons: May be too tall for some applications.
Dimensions: Base - 18” W x 14” D x 2.75”H. Stand - 18” W x
14” D x 5.75”H.
First Impression Music Iso
bearings – The Iso Bearings were not originally intended to be
used alone, but rather offered as a kit for those who want to
build their own platforms. However, our experimentation shows
they can be used alone with excellent results. Clearly
balanced toward a fast articulate quality, when compared with
the FIM platforms, they offer similar performance
characteristics to other roller bearing devices at a very
reasonable price.
Character: Detail, speed, focus.
Pros: Inexpensive
Cons: Mechanical resistance from cables should be
addressed.
Dimensions: 1-5/8” diameter x 7/8” H
Hyperion: This is a new
company on the scene that offers isolation devices on as a
sideline; their major focus is speakers and electronics. The
Magnetic Floater attempts the seemingly impossible task of
levitating a component on a magnetic field. These devices use
rings of opposing magnets to repel a circular base from its
top. On the top of the footer is a stainless steel ball
bearing to reduce contact with the component. Two versions are
available; the smaller has a weight bearing capacity of about
10 pounds each (30 pounds per set of 3), the larger 15 pounds
each (50 pounds per set of 3). I can’t say they are a perfect
realization of the concept of magnetic levitation due to
contact along the sides of the unit, but initial listening
tests suggest they are a good value; far and away the least
expensive magnetic isolator on the market. More detailed
listening notes to follow.
Character: Detail, speed, focus.
Pros: Inexpensive
Cons: Some mechanical resistance.
Dimensions: 2-3/4”D x 2”H
Marigo – Two different
products exist as of this writing, both are cones. Large and
small, bases or not, discs on smaller. Eight times out of ten
I find the smaller cones outperform the larger, the larger for
very specific applications. With bases they are almost always
bright. Somewhat complex as there are two cones and two bases
or discs. Small must be used with support discs.
Character: Variable depending on
model
Pros: Small – Inexpensive. Large – Reasonably priced.
Cons: Small – Height may become an issue. Large w/bases –
Strong character (often very bright) makes them very system
specific.
Dimensions: Small - Large – 2”H x 1.75”D
SAP Relaxa Isolation Base –
Magnetic levitation (for more details, see Clear Audio Magix
above, which employ a similar philosophy), but is a platform
rather than individual feet. The standard base supports 56
pounds, an optional fifth foot increases the load bearing
capacity to 70 pounds.
Character: Doesn’t seem to affect
tonality to any great degree. Airy, liquid, refined.
Pros: Balanced performance. Works well in most systems.
Cons: Price. Limited weight bearing capacity. Requires off
center placement of components with uneven weight
distribution.
Dimensions: 21.6”W x 16.8”D x 3.754”H
Silent Running TremorLess –
Isolation Base. Proprietor Kevin Tellekamp leads a dual life.
He’s engaged as a consultant in the secretive world of
military defense, as well as working the high end audio arena.
Yet both are strongly related. His work for the military
involves damping techniques for a variety of applications
including silencing nuclear submarines. The term used for an
operationally quiet stealthy sub is “silent running,” and has
become the moniker for the company. His knowledge of exotic
techniques and materials serves him well in designing
isolation products for high end audio.
Kevin’s abilities are respected in the field and
he’s consulted for several well known high end audio companies
seeking to reduce chassis resonance and vibration.
Character: Doesn’t seem to affect
tonality to any great degree.
Pros: Balanced performance. Works well in most systems.
Cons: Pointed feet require shelf protectors.
Dimensions: Small – 17”W x 15”D x 1-3/4”H. Medium - 19”W x
16”D x 1-3/4”H. Large – 23”W x 23”D x 1 – ¾”H
Stillpoints – Developed in
concert a former Wadia employee and the previous distributor
of the Aurios bearings, the Stillpoints are a totally unique
and unusual design.
The cone shaped device features
a ceramic ball at the apex, working together with four more
ceramic balls inside. The internal grouping is held within a
flower like arrangement the manufacturer refers to as the
calyx (outer floral envelope of a flower or bud). The
individual petals of this calyx act as shock absorbers,
damping energy transferred through the ceramic balls. The base
of the Stillpoints is flat and covered with Lexan® to prevent
surface marring and damp its metal bottom. The center of the
base is tapped and threaded to allow attachment via a threaded
rod (not included) to a component, loudspeaker or the new
(optional) Stillpoints Riser base.
Character: Tonal character lies
somewhere between the extremely fast qualities of ball
bearing devices and the warmer flavor of the composite and
ceramic cones.
Pros: Relatively small. Can be used with a threaded stud
insert for rigid coupling.
Cons: Somewhat expensive.
Dimensions: 1” H x 1.5” diameter
Symposium - Roller Blocks –
The original purveyor of ball bearing technology this company
have offered products employing ball bearing isolation methods
since 1997. A In the design, a concave dish has been mounted
in block of special isolating material. A ball bearing
(stainless or tungsten) rests in the dish and the component on
top of the bearing.
In addition to Roller Blocks, Symposium offers a
range of isolation bases (using constrained-layer techniques)
which will not be covered here.
Character: Expect the speed, focus
and detail found in similar ball bearing devices
Pros: Relatively small size.
Cons: All with all ball bearing designs, optimum results
when the equipment rack is level and stresses exerted by
connecting cables have been relieved.
Dimensions: Roller Block – 2” W x 1” W x 1.25” H
Townshend Audio: Max
Townsend of Britain popularized the use of pneumatic isolation
bases for audio applications. His line of Seismic Sinks use an
inflatable internal bladder (or multiple bladders) separating
a top and bottom plate of damped metal. A valve permits
inflation with a bicycle pump. Very low pressure is maintained
in the bladder, just enough to separate the top and bottom
panels; the less pressure, the lower the resonant frequency.
Pneumatic isolation platforms can effective in
some systems, but their idiosyncrasies can be problematic.
Leveling components with unevenly distributed weight can be
difficult to impossible with single bladder designs. Multi
bladder systems can compensate, but as the bladders loose air
the problems returns. And all the designs I’ve tried air loose
air pressure over time. Pneumatic bladder designs require
regular checks for correct pressure.
Character: Reduced background
haze, may subtly shift tonal balance to the warm side.
Pros: Isolates in both horizontal and vertical planes.
Cons: Somewhat costly, the height of the platforms may
preclude their use where space is limited.
Dimensions: 17”W x 13”D to 27”W x 14”D
Prices: $300 +
Van Slyke Engineering
Tri-Orb – Unique and rather complex devices using a
multifaceted Coulomb cones, roller balls, hyper-bowls, sling
suspenders, decoupled spring-mass absorber blocks, cork & gray
felt layers, and Neoprene O-ring sling suspension.
Our brief experience found set up to be rather
involved and we were never able to realize the performance
gains. Could be good but the cost difficulty of setup reduce
their appeal to all but the most committed audiophiles.
Character: Varies depending on
system. They were a bit bright here.
Pros: Tunable
Cons: Expensive, tedious setup, height.
Dimensions: Depends on model
Vibrapods – Viscoelastic
isolators. Most of the soft damping feet are a simple chunk of
viscoelastic material. Vibrapod molds a vinyl based damping
material into a unique shape, said to be more effective and
reducing vibration than simpler designs.
The Vibrapod’s have been well accepted by our
clients with modest systems. They also seem to perform well
under most video gear. As the resolution of the system
improves
Character: tonal balance, somewhat
diffused sound field.
Pros: Very inexpensive. Short height allows their use in
most any situation.
Cons: Leaves oily residue that may be impossible to remove
(we recommend a circle of plastic wrap of wax paper be used
above and below each Vibrapod). Will likely flatten over time
(especially if loaded to maximum weight).
Notes: Always use a circle of plastic wrap above and below
each foot.
Dimensions: 9/16”H x 2.5”D
Vibracones – The same viscoelastic material found in
Vibrapods fashioned into a cone shape with a stainless steel
ball bearing inserted at the tip.
Character: Similar to Vibrapods but with increased focus.
Pros: Very inexpensive.
Cons: Leaves oily residue that may be impossible to remove
(we recommend a circle of plastic wrap of wax paper be used
above each Vibracone).
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Notes: This
is an ongoing survey. It will updated on an irregular basis
with new information, changes to existing products and the
addition of new offerings. Be sure to check back on occasion.
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