OK ... Maybe some will see this as going to extremes, but I made one of these for my home system to put under my Lexicon RT-20 disc player, and it made an incredible difference in neutrality, soundstage, and dynamics ...

It's not finished yet, but I figured I would go ahead and show the progress thus far.

Acrylic is the single most acoustically inert material suitable for an audio shelf/stand IMO. This is because if you study it under a microscope, you would find it has literally billions of miscroscopic fibers running in all directions. This lowers it's resonant frequency to below our audible hearing threshold. That resonant frequency is approx 10 hz.



















Racquetballs are VERY, VERY efficient heat dissipators. PERFECT for my design goal of a resonance free headfi stand.

Here is the technical reasoning behind this :

Viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like honey, resist shear flow and strain linearly with time when a stress is applied. Elastic materials strain instantaneously when stretched and just as quickly return to their original state once the stress is removed. Viscoelastic materials have elements of both of these properties and, as such, exhibit time dependent strain. Whereas elasticity is usually the result of bond stretching along crystallographic planes in an ordered solid, viscosity is the result of the diffusion of atoms or molecules inside an amorphous material.

Unlike purely elastic substances, a viscoelastic substance has an elastic component and a viscous component. The viscosity of a viscoelastic substance gives the substance a strain rate dependent on time. Purely elastic materials do not dissipate energy (heat) when a load is applied, then removed. However, a viscoelastic substance loses energy as heat when a load is applied, then removed. Hysteresis is observed in the stress-strain curve, with the area of the loop being equal to the energy lost during the loading cycle. Since viscosity is the resistance to thermally activated plastic deformation, a viscous material will lose energy through a loading cycle. Plastic deformation results in lost energy, which is uncharacteristic of a purely elastic material's reaction to a loading cycle.
To damp the panels to reduce resonant vibrations, damping must be energy dissipated at the panels. The key feature of a damping material is that they are viscoelastic. Viscoelastic materials require energy to be extended and compressed. This is exactly where we want the vibration energy from the panels to go, into the viscoelastic materials and then dissipated as heat

[size=large]Racquetballs are perfectly viscoelastic [/size]

Amp and power supply goes on bottom shelf, source on top. As I said, it is NOT finished yet, and will look MUCH better when it is. Hope you enjoy this !

PS; Now I just wonder how long it takes before this thread is locked ... LOL

Very interesting...excited to see how it all comes out!

I used 1" thick acrylic, but rather than drill into the shelf itself, I simply went Gingko Audio and Bright Star route on two of the shelves, and Silent Running Audio and Neuance on the others.

While the racquetballs do a pretty decent job with vertical isolation, you also need rotational and horizontal isolation, and this is where roller bearings come in. A combination of both, and you'll be in heaven.

Bicycle tubes used in place of the racquetballs are even better, but I finally got tired of constantly refilling them when they lost air.

Looks really great!

I just don't like the color of the racketballs, black will give you better tonal balance! LOLOL

Just kidding! A good equipment rack does contribute to vibration free equipment which translates into better sound!

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I really like the Neuance shelves, and have used them myself. As far as rotational and horizontal isolation, Racquetballs do this perfectly as well. If you log on to Gingko's website, you will see where seismic tests have proven that racquetballs offer isolation in every direction. The balls themselves do NOT have to rotate to offer rotational isolation. They do this by taking the rotational movement, and dissipating it as rotational energy turned to heat. The Gingko site has seismic charts to show this isolation, via vibration reduction, in action. Fun stuff !

As far as bicycle tubes, I have used them in scores of different configurations, but have always felt they robbed the music of dynamics due to the fact they store so much of the vibrations.

As a side note : I was making acrylic/racquetball isolation shelves for years before Gingko came along, yet I have received NO royalty money yet ! LOL

Nice work!

Stunning.well thought out

mate very nice work, shows your skills

Wow guys ... Thanks for the kind words !

I still plan on putting acrylic skirts around the sides of the floating shelves, using the proper solvent around the posts where they go through the shelves ( melts the acrylic together and dries crystal clear, to make it look as if the posts and shelves are all cast from one solid piece of acrylic ), and doing further polishing to the edges of the shelves.

And yes ... I will be looking to get some black colored racquetballs

what solvent would that be that melds the acrylic?

It looks very cool but I'm not sure that I could sleep without having nightmares about monster tubeamps rolling of that stand if I had to use it

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Here you go sir :

Acrylic Adhesives and Cements | IPS Corporation


I use the #3 for gluing it into place permanently, then the #16 in the caulk tube form to fill any gaps. It bonds almost instantly, so everything has to be just right before you apply the glue. The #3 is water thin, and I apply it via a insulin syringe. Just place the needle tip at the joint, and squeeze slowly. You will see the glue wick into the cracks between the joints, and set. Once dried, it is as clear as the acrylic.

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LOL ... Nah ... There are 1.25" circular, cone shaped simples the balls sit down in. After you place your component on the shelf, the weight keeps the balls centered in those dimples. I've had my cat jump up on my $5000 Lexicon player on one of those shelves, and all it does is rock a little and resettle into place.

Tube amps, with their vibrations, could REALLY benefit from one of these shelves.

Here is some more important info about the shelf, and how the racquetballs work.

Another reason the top shelves won't roll off when bumped, is because of the 1.5" deep side skirts that will be placed all around the bottom edges of the shelves. These will be placed exactly 1/2" out from the sides of the balls after the shelf is loaded with the component. This means if the shelf was bumped pretty hard on any side, the furthest distance the balls could roll in any direction would be 1/2" before hitting a rubber ball and acting as a brake. The side skirts CAN NOT touch the balls at all however, and the system still work correctly at dampening vibrations !

Also, it is INFINITELY critical that you correctly load the balls, and that rule is 10 lbs per ball used.

This means my 3 ball shelves need 30 lbs placed on top of them. Since my disc player only weighs 15 lbs, I will have to add some kind of mass for loading. This can be accomplished in MANY different ways. The way I personally do it, is to figure out the amount of weight I need, go down to a contractor's building supply store, and buy 1/8" thick lead sheets. I cut them so they fit under the disc payer, but NOT under the disc player's feet.
You can use multiple sheets in layers to add up to the needed extra weight. Take your sheets down to the post office to weigh them, along with a pair of heavy duty scissors, and trim until you have the right weight.

Any less or more than 10 lbs per ball will affect the way the balls absorb and release energy as heat. It will make the sound warmer, or more dynamic one, and will stray from the maximum vibration dampening effect.
This also has been proven ( with accompanying graphs ) by Gingko using a siesmograph machine.

Nice work !!!

This is exactly the kind of setup I need for my head fi rig.

How did you cut the dimples and to what depth and diameter ?

Peete.