what is the theory behind maple stands and racks?

Llyodc,

Here is a very theoretical and probably not very satisfying explanation for what I have experienced first hand with my system. I think part of the appeal of hardwoods (not just maple) for this application is that in fact they are not so hard that vibrations just bounce off the material and back into your gear. When the piece of wood is thin like a violin or a guitar, the wood will resonate a great deal (a good thing), and these musical instruments tend to be made with thin pieces of softer woods put together in configurations that will resonate just the right amount.

When hardwoods are cut or glued together into thick slabs, their resonant properties are different from thin pieces. Vibrations entering the slab from one side are dampened as they travel through the material and as they are reflected back. So while the maple slab doesn't absorb and eliminate all vibrations from your gear and the room, it definitely mutes them. Think about the difference between being inside an old wooden ship made of thick timbers and a newer steel ship made from relatively thin sheets of metal - they definitely "sound" different with the steel being much more resonant and "live" sounding.

So why not use particle board or MDF which are less lively than solid or glued hardwoods? All I can say is that they are either TOO dead, or because they lack the complex structure of intact wood fibers, they cannot drain vibration away from your gear as effectively. Apparently some vibration is a good thing!?!

Lastly, the best hardwood vibration platforms I have used are thicker and very heavy - a full 2" thick or more - so they have a lot of inertia to stay put and not respond to vibrations coming from the room or your gear itself. Thinner glass, steel, MDF shelving while strong enough to hold up your gear would be easier to set in motion - especially by lower and more powerful frequencies.

Hope that helps a little.

Mapleshade claims they have done comparison tests and have found that North American Maple "sounds the best". They are in the business of selling the stuff, so I take their claims about maple with a pinch of saw dust. Who knows - maybe a little bit of the right kind of "sustain" in your platform makes your audio gear "sing" like a stratocaster?

In my limited fooling around with different isolation platforms, I cannot tell the difference in sound between Maple, Ash or Bamboo. BUT I find that I can tell the difference between intact wood and MDF, particle board, synthetic materials or steel (although Aluminum may be a good choice), with wood sounding the best to me. And the thicker and heavier the wood the better.

I can see it now - knownothing's Genuine North American Tree Stump Equipment Stands...

Interesting - I had a similar result with solid state amp. Wooden platform had almost no impact on sound. Wooden blocks in place of amps rubber feet and placed on polyethylene board = little but slightly less appealing effect. Amp's rubber feet directly on poly board with the board on metal blocks on shelf - slightly better.

For all other applications (speakers, CDP, TT) I use wood - maple, ash and bamboo. The applications of these materials are driven more by cost, size available and aesthetics of a each piece, rather than focusing on the particular variety for given use. As long as the wood is fairly hard, it seems to work pretty well, again the thicker the better. Someday I may get around to doing an independent test of Mapleshade's claims for NA maple.

On a related note, I have tried Sorbothane dots directly under my gear, and used it to isolate shelves from stands and heavy wooden platforms from shelves. In these applications, I was not happy using the material to decouple equipment from whatever is directly supporting it as it seems to suck some of the life out of the sound. But I am happy using this material to decouple the platform from the shelf, or the shelf from the rack (can play system louder through room speakers before compression or distortion sets in).

This leads me to believe the purpose of the wooden platform is to drain INTERNALLY generated vibration away from your gear, while the purpose of an elastic material like Sorbothane is to decouple or isolate your gear from room vibrations originating from your speakers and transmitted to your gear through your rack. I say this because the benefits of the wooden platforms and anything you put between the platform and your TT or CDP (e.g. wood or metal blocks, cones, Sorbothane, etc.) are clearly apparent even when using headphones, and so must be interacting directly with the gear irrespective of room vibrations.

Finally, for your tube amp, I would think the platform material is a more critical factor than it seems to be for my SS rig. Since tube amps generally have big transformers, they can generate a significant amount of vibration on their own, and since the tubes can be affected by both internal and external vibration, I would also experiment with heavy wooden platforms and spikes/cones/Sorbothane as well for that application.

Dan_ed,

I think you are most certainly right that different approaches and materials work better for different components. I use heavy wooden bases for many because I haven't found something better yet (but may try some of your suggestions - especially for my TT which I don't think I have quite dialed in yet!?!)

One generality - for most applications I haven't found a piece of wood yet that I thought was so thick and heavy that it actually degraded rather than improved the sound of the supported component compared with a thinner and lighter board.

Thus I see we are at the dawning of the era of the "salvaged timber component stand look" where, as a backlash by pocket protector'ed electronic hobbyists and knuckle dragging hedonistic red meat audiophiles towards the new effeminated PC Enviro-Nazi Congress and Administration, and in search for the ultimate HiFi "High", we as a group reject the increasingly passe' B&O minimalism along with our Volvos, Cuisinarts and All Other European Kinds Of Things in favor of large old growth stumps in near natural condition arrayed along one wall of the listening room, each one supporting a single massive tubed component resting on pure plutonium footers, connected by Alpha Beta Gamma Delta Double Triple Helix "Atlantic Crossing" cables to taller stumps on each end, hollowed out to contain the 35 blood diamond speaker drivers and the finest PBDE and pthalate laden crossovers. All in Pennsylvania (USA!) Amish Maple, of course...

My guess is that the wood "absorbs" the vibration, just as your house absorbs and dampens noise (to a greater or lesser degree). The thicker and heavier the wood, there greater its ability to absorb and dissipate vibration from either direction. I am sure certain woods are better at this than others.

Stevenball,

Your example of the vibrational consequences of a poorly hit ball is quite graphic, but if efficient transfer of vibration is the only story wrt audio platforms, then I think wood would not be the material of choice. There are much stiffer materials available that would pass all the vibration through to whatever your block is sitting on. Unfortunately, they would also pass ALL the room vibration imparted to the rack-footer-platform "system" back to your electronics gear. So if maple absolutely "does not absorb vibration" as you suggest, that would not necessarily be a good thing for your hifi. Fortunately, for musicians, music lovers and audiophiles everywhere, this is not the case.

Maple is very dense and very hard for a wood, but in applications for musical instruments and audio equipment platforms it displays complex behaviors. It functions to dampen some of the vibrations, transfer others, and under certain conditions, it can actually amplify or increase the resonance of certain frequencies. The tendency to accentuate certain frequencies may have positive or negative effects on overall sound in hifi applications.

From the Imigi Audio Products webpage:

"...The benefits of solid-maple as a component platform have been known for many years. The sonic properties are unique. In addition to the natural damping properties of maple, when the platform is properly designed, it has a unique ability to allow upper harmonic overtones to fully develop. This is often apparent in the way you can hear a bow drawn across a violin string, the crispness of a sax or in the decay of a drum beat..."

In fact, these complex and unique resonance and damping properties are what makes maple valuable for certain applications in acoustic instrument manufacture.

See this exert from "Tapping Tonewoods", by Dana Bourgeois

"How the Selection of Species Helps Define the Sound of Your Guitar"

Acoustic Guitar Magazine, March/April 1994

"...Maple and walnut tend to be more acoustically transparent than other tonewoods, due to a low velocity of sound and a high degree of internal damping. That is to say that they allow tonal characteristics of the top to be heard without the addition of extraneous coloration and may even serve to attenuate some of the overtones emanating from the top.

The harder, denser examples of these woods, such as sugar maple and black walnut- particularly quartersawn examples-tend to lean slightly more toward the tonal direction of mahogany, while softer examples, such as bigleaf maple and claro walnut, tend toward greater tonal transparency. Curly, quilted, or bird’s-eye figures do not seem to have much effect on the tone of the wood, but they can be used, like bearclaw, as an indicator of other properties. Quilted figure, for example, occurs most often in softer species and is best displayed when the wood is flat sawn-two characteristics that tend to produce higher damping properties..."

So I surmise that, in addition to wood type, thickness, mass and angle of cut of the piece of wood will alter the way the wood responds to, absorbs or resists vibration. Greater thickness and mass means greater energy required to get a maple or other wood platform to resonate. Thickness plus cut can also increase the internal path length, and the number and configuration of wood fiber bonds available to dampen vibration. That's why guitar backs aren't four inches thick! For some applications, a thinner platform may be better because the resonant frequency of the wood actually enhances the perceived performance of certain electronic gear.

Typically 2" - 4". Some application may work better with thinner platforms. For turntables and CD players for me, thicker has worked better.

By better I mean less exaggerated and more "natural" sounding highs, smoother but more detailed midrange, cleaner and better articulated bass. The whole presentation just sounds more coherent and better put together.

I use 2" thick bamboo cutting boards - work very well.