Best building material for vibration free shelving

I am building some built into the wall shelves for my VPI Classic 2 SE turntable, amp, preamp, CD player, and old Burwen TNE 7000A transient noise eliminator (that’s one for you old-timers to remember), as well as my DISH Network receiver box. The shelves must match in appearance the typical looking built-in wood bookshelves already in the room. The shelves will be located directly under my 45" wide flat screen television. They will be wide enough to hold two components side by side, other than the VPI turntable which will have the top shelve to itself due to its extra width. I will be building the shelves high and deep to allow for plenty of air circulation around the components. They will be painted.

My question is, what materials might you suggest building the shelves with to minimize vibration? If they were for books I’d normally build the sides, and top out of 3/4" birch sided plywood, the back out of 1/4 inch luan plywood, and the shelves out of oak to deal with the weight of the books without bending. I will be adding vibration damping feet under each component and am not looking for suggestions along those lines, only material and perhaps design recommendations to reduce vibration.

I was researching this last night online and on site, and saw recommendations to use four thicknesses of 3/4 inch High Density (HD) MDF, also to use granite or marble under the turntable, among other recommendations. I was wondering how birch veneered plywood would work too, as it’s ply’s, I believe, have their grains running in opposite directions. Maybe there’s some way to isolate the uprights from the horizontal shelves to reduce vibration transmission.

What would you think would work best for these built-ins. I’d appreciate any recommendations you have or your experience on this subject. Thank you for any ideas.


I can’t help you much but I have essentially the same project coming up.

I will also use a high quality 3/4 plywood with hardwood veneer exterior.

The recommendations you got on the internet are probably sound. But who has the time, skill, resources and money to build with marble or granite? You could certainly get a counter top installer to do it but that is hardly going to fit the decor of the existing shelves you mentioned.

Like wise, 2.5 inches of MDF is simply going to be ugly if that thickness is visible anywhere.

To be honest, I’d just focus on making them sturdy and let your basic vibration reduction techniques handle the isolation tasks. Thats what I’m going to do.

I think the primary area you would want to focus on in terms of isolation is how your shelves will be suspended. My middle shelf, which the pre-amp will sit on, will be adjustable. If you will have adjustable shelves you could always add strips of sorbothane to the underside of the shelf that contacts the support pegs or brackets.

I’m not into vinyl to any serious extent so isolating a TT is not one of my issues. My amp weighs 100 pounds so that will be an issue for me. You could easily get a piece of granite from a counter top maker and have it sitting on the top shelf with sorbothane feet under it and then whatever else you use to isolate the TT under the TT resting on the granite.

George, appreciate you replying. I actually do have one 3/4" thick piece of marble the exact 40" length I’d need. I had it made up years ago to fit on top of an old antique cabinet housing my stereo equipment. My Bang and Olufsen turntable sat on it. The cabinet's long gone, but I couldn’t bear to throw out the marble. I just wasn’t sure if reusing that would be helpful of not. Somewhere I came across someone saying that granite can vibrate in and of itself in response to sound waves. Who knows? Lots of contradictory advice on the internet.

I usually make shelving by dadoing slots into the uprights for the shelves to fit into. You might have a good idea there about using adjustable shelf brackets, and sitting the shelves on them with sorbothane in between the shelf, clips, and maybe the uprights too. I’ve lots of leftover metal brackets and clips out in the garage for adjustable shelving. Where do you get sorbothane?

I just read the instructions for my new VPI Classic 2 turntable. They said the turntable is heavy, like your amp, and has its own isolation feet, so it should not vibrate. So that simplifies that part of the equation.



Anybody else out there with ideas? I’d love to hear them.

As far as reducing micro vibration is concerned, I've had good results with corian on my steel sand filled rack, using the half dome soft iso (I believe) disks between them. It looks very nice as well, but doesn't look like wood. The shelves themselves are only 13 X 16. Not sure how well it would work at 45 inches.  
I have 2 maple platforms that need refinishing, I used one for my Scout and the other for my Prime.  The larger is 22 by 18 by 3 inches thick of air dried maple.  The smaller one is 18 by 15 by 2 inches thick of air dried maple.  I painted them black but they look crummy.  Need to be sanded and repainted.   If someone wants to drive up to me, they can have them. I will NOT ship them. Send me a PM
I agree with stereo5, solid maple is an excellent turntable platform, the thicker the better.
as weird as it sounds, I cut drywall squares and secured them with sticky wood veneer.
the best anti-vibration solution.
@skyscraper - I use...

for amp and turntable
- 3/4" MDF shelf
- 1/2" 18" x 14" granite tile (cut to tat size)
- with tool drawer liner in between them

Tool drawere liner like this product

I buy it from the dollar store - very cheap :-)

For smaller components (phono and Bluesound Node 2) I use 3/8" MDF and 3/8" granite tile with the same drawer liner between them

Each shelf has sorbothane between the shlf and the Rack;’s metal frame

My TT plinth is also made from 3 sheets of 3/4" MDF glued and clamped. It is very dense and does not vibrate - I would have to believe 2 sheets glued would make a very good shelf.

Each component is currently supported by 3 wooden feet like this...

The Amp and TT has the large feet, the phono stage has the medium feet and the Node 2 has the small feet

The wooden feet made a noticeble improvement in the size and precision iof the mage.

I have heard good things about Mapleshade product and their web site may contain some useful info for a DIY person

Hope that helps - Steve
I have 3" solid maple bought on here from lady in MI underneath both my DD and belt TT on top of a 1" MDF cabinet .I have tried ALL the usual suspects under their feet and found 6$ virapods best .
You can get various forms of sorbothane on Amazon. It can be expensive.

I'm not a fan of MDF for long horizontal load bearing pieces, like a shelf. MDF doesn't compress much and it has a lot of strength when standing vertically, which is good. But in the long axis it breaks fairly easily...think long shelf with something heavy in the middle. 

williewonka, I made some feet for my preamp out of walnut that I had lying around. The rubber feet of the pre-amp sit in the little divots on top, the wood blocks sit on 1/4" sorbothane pads. Does any of this make any difference? I have no idea. Kind of doubt it, but total cost was about $12.
@n80, not a good idea to use the preamp’s rubber feet coupling into a hardwood footer. You can’t rely on the stock rubber feet to provide any isolation; also, rubber will colour the sound and the feet are not secure since they are either glued or screwed into the preamp chassis.
For transparent isolation, footers should sit under the component itself. This way any vibration will travel from the underside of the chassis to the footer. There are two methods of isolating a component, either drain vibration to a platform or plinth, or decouple the component from the shelf.

There are many threads on this subject in the archives. Geoffkait has provided very good advice regarding acoustic isolation.

Your walnut footers look like a good design for draining vibration and also for isolating acoustic/ mechanical vibration from the shelf. What you are missing is a set of cones where the flat end sits under the preamp and the point sits in the dimple of the walnut footer.

@williewonka, have you compared your wood cones with Myrtle wood blocks? I'm using the blocks under my tube amp and find that the image is not well focused perhaps due to vibration.

I like the idea of using wooden cones rather than blocks. I also found these cones...
These are made of oak, the Glasshouse are beech. Any thoughts if using cones would be superior to the Cardas Myrtle wood?

I've said it before, and I'll say it again. 3/4"-19mm 13-ply Baltic Birch is really stiff, and fairly non-resonant, much more so than Maple. Two pieces of it with a thin sheet of constrained layer damping between them makes for an excellent shelf. Maple may be liked for it's "pleasing sonority", but who wants that? Apparently a lot of people ;-) .
lowrider, to be honest, I made those because I was bored and bought the sorbothane on a whim. I can hear absolutely no difference in SQ from when the line stage sits right on the rack, right on the sorbothane or in the configuration I described above. I suppose I just don't have the ear for it.

But one has to wonder why a company like Audio Research would put crappy feet on an otherwise high end and fairly uncompromising piece of audio equipment. And for all I know, they are not rubber. They are also more or less cone shaped. So the contact point with the wooden blocks is actually very small

So here's my somewhat facetious take on my setup:

Special cone shaped vibration damping feet on the pre amp fit into a custom designed dish shaped concavity within the American walnut isolation blocks (English walnut will not do) whose grain orientation, aging and density limit sonic vibration transmission. These blocks sit on sorbothane pads which isolate the system as a whole. These sit on a spiked audio rack with thick MDF shelving. Considerable effort was expended tuning this components for that perfect sonic quality. ;-)
Bdp24, what are you using for the "constrained liner damping"? Also How are you connecting the two pieces of 13 ply Baltic birch together, or are you simply setting one on top of the other withe the damping material in between? I read somewhere where one person glued damping material on either side to two separate boards as you describe. Are you setting the shelf on clips, like a typical adjustable shelf like George described above or are you connecting the shelves to the vertical uprights? Do you feel the 13 ply would be less resonant than HD MDF. Sorry for so many questions but I think you’ve put forth some good ideas here.

N80, agree with you that MDF would sag spanning 40 inches. I figured on bracing the shelves with an upright in the center, probably have to do the same with Baltic Birch plywood too. I’ll look on Amazon, and also price, sorbothane as you suggest. I was hoping one of the big box stores like Lowes or Home Depot might carry it.

Stereo5, dill, and schubert4, thank you for the suggestion on using maple.

Czaeivey, I like you idea for using sheetrock squares. They likely wouldn’t vibrate, but also would likely collapse under the weight of heavy components like the amp, unless you are laying the sheetrock on another shelf material. I’ve lots of scraps of sheetrock laying around.

Steve (Williewonka), After reading your suggestion, I might try using my piece of leftover marble, and set it on the top shelf under the turntable with a piece of tool drawer liner, or constrained layer damping in between, once I figure out what that is and how to get it., Thanks for your ideas.

Thanks all for you input and suggestions. I'll be incorporating several of them. I’ve learned some new things already too, Never heard of using sorbothane, or of constrained layer damping before.

Also, and I’m repeating myself, if anyone knows which is less resonant between High Density MDF and 13 ply Baltic Birch, I’d very much like to know.


@n80, I'm sure the feet on your ARC aren't crappy. In fact, some high-end manufacturers use quality aftermarket footers on their amps so that the voicing is what the designer intended. My point is that usually the feet on a pre or an amp are screwed or bolted into the chassis. This creates a weak spot that is vulnerable to vibration.

It's great that you're pleased with the sound of your system. i remember when you came to the forum asking for advise. And BTW, your walnut isolation blocks look better than most tweaks I see for sale.

@skyscraper, I use ASC (Acoustic Science Corp., maker of Tube Traps) Wall Damp as constrained layer damping. It has a "tacky" surface like double-sided carpet tape, so holds together the two pieces of wood it is installed between. It was designed by Art Noxon to be installed between double layers of sheetrock in listening rooms, as a vibration killer. It absorbs and dissipates the energy fed into it, making it a great means of constructing non-resonant shelves. I have been in a room constructed with Wall Damp between two layers of sheetrock, and the walls were VERY dead.

Another product created to provide constrained layer damping is EAR Isodamp, the blue stuff you may have seen. It's not as tacky as ASC Wall Damp, so the two pieces of wood it is placed between may need to be glued together.

I'm not sure if 13-ply Baltic Birch and MDF are equally non-resonant (I suspect MDF is), but BB is much stiffer than MDF. I put my 60 lb. turntable (with four feet) on top of two layers of 3/4" MDF, the MDF supported on two cones in front and only one in the rear. The rear of the MDF bowed under the weight!

Bdp24, appreciate you getting back to me. I’ll give the 3/4" Baltic birch a try. I’ll track down some ASC Wall Damp too.

What I think I am going to try are shelves constructed as bdp24 recommends. They will be edged with a strip of sorbothane to butt against the vertical side walls as Steve suggests. I’ll make the shelves adjustable in height, sitting them on clips on vertical tracks with sorbothane between the shelves and the clips, as George suggests. Lastly I’ll set my slab of marble on the top shelf for the turntable, over a piece of padded shelf liner as Steve suggests. I’ll edge the slab with sorbothane too.

I’ll set the components on footers, likely the economical $6 virapods schubert recommended.

If anyone see any flaws with this plan or ways to improve it, please let me know. Thanks you all.


I'm quite keen on Panzerholz, a German plywood-like product. But it's damn pricey, so most people won't bother.
Made my own footers from a 1.5 square piece of corian 1/2" thick.  I put a dimple in the top and set a Druzy stone in the dimple.  Thw stone is kind of like lava.  When you flick it with your finger its a dull click.  You can put a piece of tooth pick in the bead and set it in a small hole in the dimple to keep it more stable.  You can also put a tiny spot of blue tape on top for more friction and avoid any scratching.  $1.50 footers each. 
Terry, I'll look Panzerholz up. Where do you access it?

Kingrex, I'll have to look up what a Druzy stone is. Thanks for the economical idea. There's few corners to be cut in the high end audio market.

lowrdier57 said:

" It's great that you're pleased with the sound of your system. i remember when you came to the forum asking for advise."

I'm very new to all this...which might be why I don't hear any differences in the various low buck tweaks I've made. However, I do hear differences in other things like speaker placement, listening position, differences between DACs, possibly some room changes.

And this brings up another subject that puzzles me somewhat and is relevant to this discussion: Component placement. We hear that your pre-amp/amp should not be between the speakers because of sonic vibration from them. Fine. I get the point. But I have some problems with this. First, for many of us, there just isn't any other option. Second, why is it better to have the components somewhere in front of the speakers than between and behind them? Some say you can find a sonic dead spot in the room and put them there....but that sounds impractical in the reality of most rooms. One audio-critic said the components should be in another room altogether! 

Anyway, when I build my shelves the components will be between and slightly behind the speakers. No other option. This also brings up a couple of issues. First, vibration transmitted through whatever the components are sitting on....which is the focus of this discussion...but what about sound vibrations that strike the unit? You can buy room baffles and reflectors....does anyone make some type of sound absorbing or reflecting material that can go in front of a pre-amp that will fit on a shelf or a stand?
I did not understand this to be a air vibration transmission back into the signal.  Think about where bass is strongest.  Usually at the back wall and corners.  Sure you could get some, especially through vinyl.  My understanding is you have a large reflection in between your speakers messing with imaging and maybe smearing the timing.  

My gear is between my equipment but I keep my rack sides open, not solid. 

Friends of mine keep the amps real low to the ground, then a slender open rack between and as far back as possible.  

I have other friend saying 30 foot single ended interconnects may shave a little top end, but the staging and clarity outweigh the loss.  As long as you don't get RF interference.  If the long interconnect picks up radio, well? ????  

@n80, I’ll address one point, your component placement should be fine. It’s furniture or audio racks between speakers that affect mostly imaging and other sonic attributes. Open racks are preferred. Speakers need space or air around them for best reproduction.
Most owners move their speakers forward of the rack/console.

N80, not taking a shot at you.  IME, when your system gets more dialed in you start to hear  small changes more readily.  Also, all the little stuff adds up over time.  Provided your actually keeping the good and removing the bad.  That can be the hard part.  We seem to gravitate to high frequency.  We can easily make our systems bright and fatiguing when we think we are getting extension and resolution.  That miss applied  high frequency will mask true midrange clarity.  
I bought a preamp from a local builder and he spent 2 afternoon teaching me how to tune.  It changed my stereo.  At first I thought it was going flat.  Then with a couple more changes it clicked.  It was an astounding gain.  

I like the rack Skyscraper is building.  I would just be careful of Sorbothane.  It can suck life.  An air gap can be better than coupling a hole with material.  Spock on audipshark uses a thin silicon between his plate materials.  He says he's getting good results.  I do like the ASC wall damp.  Never used it, but I am going to try it between my plates of corian and plywood.    
I guess me simply placing my componets using the feet they came with on my 20 year old rack with MDF shelves situated between my speakers is audio sacrilege? Oh well I'm getting old, hearing isn't what it once was and my stereo is junk so Apollo may over look my failings but damn if I could ever notice vibration being a problem. 
Kingrex, a couple of questions; when you say Sorbothane can suck life, could you elaborate on that. What would be the negative effect, and how and why might this be occurring? I am trying to learn, and really don't understand how that might happen. I could easily leave an air space as you suggest between the shelves and sidewall with maybe a few spacers to keep the shelf situated in place instead. Could you provide a link to that "Spock" reference on Audioshark. I'd like to read it. Maybe silicone would be better than the this application.

Also, what are some of the things you learned about how to tune your system from the local builder from whom you bought your preamp? Sounds interesting, and I'd appreciate if you could share some of his ideas. Thanks,

N80, Interesting comments. I would have liked to put my components in a separate room, but read it was necessary to keep the cabling runs to the speakers a short as possible to prevent high frequency loss. I'm moving my equipment over five feet to the center of the room to accomplish this among other reasons, like not having them directly behind a speaker. Considering the high cost of high end audio cabling, there are certainly economic reasons for using the shortest wiring lengths possible too. 

Hi, a few years ago I had built a table and an accompanying amp stand out of three sheets of 3/4” MDF.  I trimmed it with poplar and stained it all. The legs of the table are 3”x3” pine legs. The platform for the amp stand rest on wide strips of the mdf that was scrap from the construction. On the table my CD player sits on a maple board in turn rests on brass high hats resting on rubber footers, and tube pre rests on the table similarly except no board. I was trying to go for a mission style along with a stable platform. To do it over I would have sandwiched BB between the outer MDF. I also like the idea of membrane between the layers. My equipment is between speakers but is open around the equipment pieces. Interesting is that the equip testing directly on the MDF is muddy as opposed to the current config that does activates the high freqs. In lieu of the pine I would now consider some type of steel or aluminum tubing filled. I do have wall and corner treatments. Anyway I still am tweaking. Just thought I’d share my experiment.
I think your question is misguided... You should be asking ..How can I isolate my TT shelf from my built-in's?

slaw’s point is well taken. While a stiff shelf is better than a weak one, neither provide isolation to any appreciable degree. Baltic Birch is not only stiffer than MDF, it is lower in mass, so it exhibits a higher-frequency resonance, and absorbs, stores, and releases less energy. The problem with Sorbothane-type rubber products is that they isolate down to a corner frequency of around only 10Hz, below which their isolation properties roll off, becoming a low-pass filter (very low frequencies pass right through). A turntable benefits from isolation to as low a frequency as possible---10Hz is not nearly enough.

The best turntable isolation is that provided by the electron microscope platforms made by a number of companies, but they aren’t cheap---over two grand. Roller bearings (Symposium Acoustics, Ingress Engineering, FIM) provide good lateral isolation, but couple in the vertical plane. The best lower-cost alternative I am aware of is the Townshend Audio Seismic Pod, at around $100 a piece. Put a set of those under your turntable shelf (and/or speakers, CD player, and electronics) for isolation to a pretty-low frequency---2-3Hz. Watch the Townshend video demonstration of the Pod on You Tube.

If you’re determined to build a structure for isolation I would turn to the Flexy Rack of yore. Contrary to popular opinion very rigid structures do not isolate as well as flimsy flexible structures. The easier it is to move an object in a given direction the better the isolation in that direction. Another example of a flexible structure is the Mana stand, also of yore, that employed multiple glass shelves on a rigid frame.
BDP24 has some very good points.  

I hear pods pushed all over.  Some like them, others do not. Its gonna be hit or miss.  

I have a friend with a full set of SRA stands. Huge and heavy.  Vibration can be turned into heat and dissipated if done right.  

Electron microscope stands were the rage but kind of fell out.  Of course people like Mike Lavigne use them, but they are rebuilt with linear PS and other mods.  Far to expensive for the average guy.  

Build your stand.  Try Isopods.  Try my inexpensive feet. Make them with acrylic from tap plastic.   Something will jump out as right.

In all honesty,  I don't know I could make the first big step on my own.  Once your setup properly, the small tweeks become more apparent and easier to gauge as good or bad.  I guess my best suggestion would be, if the music is strident and hard, you probably have to much high frequency. Rhodium power cords were a problem in my system.  Try just plain pure copper. If the sound is flat and blotted, your stand will help.  Try footers of different types.  Spongy gel types will probably go the wrong direction.  
IME no matter ow much you spend vibration is inevitable. I live about a half mile from railroad tracks, and I can feel it through my concrete floor when a train rolls through. 

Significantly cheaper and superior is Machina Dynamica Springs. He has a variety to accommodate variouscomponent weights
Italian, thanks for sharing your experience.

Slaw, I've asked a few questions here. Bear with me. I'm uncertain which one are you referring to as misguided. 

Bdp24. I looked at the Townsend pods you recommended and will track down the Youtube video.

Right now, what I need to find is basic. I will have metal clips holding up the shelves. The clips will be on standard vertical tracks, commonly used for adjustable height book or cabinet shelves. I'm sure you've seen them. The flat portion of each clip the shelves will sit on is approximately 3/4" x 1/2".  I want to find some vibration absorbent material to sit on the clips between them and the shelves. I was thinking maybe 3/4" by 1/2" pieces of sorbothane. But, since you mentioned sorbothane doesn't isolate to low enough frequencies there must be something else to use, maybe silicone as suggested above.  

In the interest of full disclosure, the top shelf to hold the turntable is already in place. It was built years ago to hold one of those old fashioned enormous wide screen televisions we were stuck with before flat screens came out. I am building the rest of the shelves for the amp, preamp etc underneath that pre-existing shelf. I will be placing my marble slab on that pre-existing shelf with a shelf liner under it, as suggested by Williwonka above to help defeat vibration and resonances. I wonder if bdp's suggested constrained liner damping might work for this as well under the marble. 

I will later find feet for each component that hopefully defeat any remaining resonances or vibration. Any suggestions on what material might be advantageous to sit between the metal clips and the shelves would be helpful

Kingrex, I wish I could afford something like an electron microscope stand. But I'm hopefully purchasing some exorbitant for me, $10,000 speakers next week, so I have to not bankrupt myself otherwise. If my late wife was still in the land of the living, I guarantee you I would be doing none of this. I can hear her in my head saying "What do you mean you need an electron microscope table, what do they cost?" 

Tweak, sorry the train is so close to your home. I'll look up the Machina Dynamica Springs.  They sound interesting. 

Thanks again all.


Wish I could afford $10k speakers.  I just connected my Pure Audio Project trio 10 last night.  Breaking in and tuning now.

My TT sits on my shelving stand.  Nothing fancy.  I built the base and plinth so I took the time there to isolate.  Have fun. 
You know, I know a dealer who sat his amps on little tables from IKEA because they were made like cardboard.  Corrugated paper between a couple thin plywood pieces.  He said it was like an air gap.  Poor man stand, but pretty effective he thought. 
Kingrex,  I've been happily listening to my $790.00 pair of Dahlquist DQ-10's since 1976. So you're way ahead of me with with your Pure Audio Project Trio 10's. Since you mentioned the Trio 10's, I went and looked up a review on them, which coincidentally referenced my DQ10s a couple times. The  Trio 10's got an excellent review  and are striking in apppearance, so congrats on that purchase.  

Gawdbless, thanks on the link. 

@lowrider57 - I have not tried the wooden blocks.

The cones look very similar to those beech cones I purchased and cost less, but they are Oak and it might depend if it's white oak or red oak.

I like maple for audio purposes - quite hard with a very uniform and tight grain.

I also hear ebony and rosewood is vrey good

I'll keep you posted as to how the brass and Bronze feet turn out, but at this point in time the beech feet sound great

Cheers - Steve
I'll be honest, I think the idea that different woods will change anything in a measurable, repeatable fashion is a bit of a stretch. I'm not saying different woods don't have different characteristics that can be heard, I'm just saying that when you are talking about the characteristics that effect the transmission of vibration I'm not sure you can be specific species to species. Every tree within a given species is different. Different ages of tree have different ring and grain structure. The conditions under which a tree grows affects its structure as well. And this is not to mention how the wood was dried, cut and treated. All of these things can have significant affects even on macro things like furniture, axe handles, baseball bats etc. Such effects would even be greater on micro issues like vibration transmission.

So in my mind a young harvested, poorly dried and treated specimen of one species considered to be the best might be inferior to a specimen of a less well regarded species that has better grain structure due to age, growth rate as well as better preparation and finish. 

Think about basic pine. Young, high growth rate yellow pine is soft as putty (maybe that would be a good thing??) whereas the heart of very old pine that died while the tree was standing can literally be hard as rock...sometimes it won't even split down the grain.

n80, you speak the truth. Years ago old pine, especially heartwood could be used for flooring due to its hardness, for example. Couldn't imagine any pine you find nowadays at the big box stores being used for that purpose. 

If you want to try something cheap, try one ceramic ball in each of the walnut feet. You'll only want to use three (not four) feet with the ball high enough above the walnut so it's the only thing making contact with the bottom of your component. Put a very small dot of blue tack at the bottom of the dimple in each of the walnut feet to keep the ball from rolling. Grainger sells ceramic balls. 
@williewonka, thanks, the cones are a similar style. I guess there's no way to predict the audible difference between beech and oak as footers.

 With regard to a wood platform or plinth, is it possible to make an educated guess as to the sonic effect between different hardwoods? The difference between a hardwood and softwood is obvious IME.
 @n80 perhaps you might have an answer?

@gawdbless , I'm using that exact bamboo board turned upside down. It was recommended on a thread a while back.
I have seen better quality bamboo cutting boards, but this one is strong. It's under my 60 lb. tube amp. I'm in search of the right kind of footers, haven't found them yet.

“With regard to a wood platform or plinth, is it possible to make an educated guess as to the sonic effect between different hardwoods?”

>>>>All things being equal a thicker platform should perform better than a thinner one because it’s stiffer. Stiffness is required to bending forces, one of the isolation directions. Of a platform is used in conjunction with Springs the type of wood is not very important because the wood platform, as well as the component, is isolated from vibrations coming up from the floor. Also, any vibration that occurs on the wood platform, including acoustic vibration, can be easily dealt with by applying damping. Another variable is type of cones under the platform and under the component that is on top of the platform. How the wood is cut, with the grain or cross grain, should be audible. There is also the beauty of the wood to consider, e.g., Walnut, Maple, Cherry.
I just finished converting a built-in box or cove that held a big old TV.  It put an open box in the room and is a nightmare for audio perfection.  After lining the sides and top with carpeting I have add 12' x 12" accoustic tiles to back and corners.  The base is a 3/4" plywood sheet that sits on braces on each side.  I built a laminate of my own.  First layer is 1/4" cork, then a layer of rubbery shelf sheeting, then carpet, then a 3/4" finished poplar board (well varnished), then the 2' x 1' ceramic tile that I glued a layer of felt to the back so it would not scrape the wood.
My TD-160 now sits on Vibrapod risers that sit on this sandwich that has NO significant vibrations at all.  If you don't have a slab of marble the 2' x 1' pieces are about $3.00 each and easy to stack a few up if you want the real heavy weight.  A slab of marble would not be any better performer than a well thought out layering and lamintion.
Add on:  instead of spikes on my 4 foot homemade towers I have baking pans that fit the 12" x 18" footprint of the 100+pound speakers and filled them with sand.  On a carpeted, poured concrete basement floor the vibration issue is 'dead' in the sand.  
"@n80 perhaps you might have an answer?"

No. I have a basic understanding about different types of wood but no real knowledge about which characteristics are best for audio. The total of my experience consists of sorbothane, walnut and MDF.

In fact, it seems that the waters are very muddy in regard to anchoring vs isolation of various components.

I’m surprised no one has mentioned it (or maybe I missed it) but there are viscous fluid dampers for various types of machinery and sensitive equipment. I’d assume someone makes these for audio equipment. The ones I recall for machinery were terribly expensive.
rcronk, yours is the exact situation I've got here. What I figured on doing is to raise the flat screen TV which covers the existing opening, only high enough to make a space for my VPI turntable to set, and high enough to be able to remove it's dust cover. I was going to leave the remaining unused space behind the flat screen open. I figured that would be a good area for heat from the electronics shelved below to dissipate. I hope that open space doesn't create audio side effects like you've experienced. If so I may have to try some of the treatments you've done. Thanks for the heads up.

The existing box is completely framed in with 2x4's and is made out of 1/2" plywood. So it will probably vibrate like crazy. Hopefully using my leftover marble slab with rubbery shelf sheeting under it will handle this issue adequately for the turntable. The rest of the shelves will be built underneath the current opening and will be of Baltic Birch and constructed as some here suggested and I've outlined above.

Gawdbless ,any idea of what the resonant qualities of bamboo are?

Geoffkitt, one of the  advantages of Baltic Birch plywood, I'm guessing, is the plys' grains are cross matched, each plys' grain going in opposite directions. I would hope this would damp resonant vibration. I'm only venturing an uneducated guess here though. We'll soon see.