Best building material for vibration free shelving

I think your question is misguided... You should be asking ..How can I isolate my TT shelf from my built-in's?

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.

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 sorbothane.in 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. 

Mike

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. 

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.    

@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.

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? ????  

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?

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.

Mike

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. 

I'm quite keen on Panzerholz, a German plywood-like product. But it's damn pricey, so most people won't bother.

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.

Mike

@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.

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.

Mike.

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. ;-)

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 ;-) .

@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...
http://www.russandrews.com/us/system-racks-supports-equipment-feet/
These are made of oak, the Glasshouse are beech. Any thoughts if using cones would be superior to the Cardas Myrtle wood?

@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.

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.

https://images.nikonians.org/galleries/data/3564/IMG_10421.JPG

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 .

@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
https://www.banggood.com/3x0_3m-Drawer-Padded-Shelf-Foam-Black-Box-Liner-Non-Slip-Lining-Grip-Rubber...

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...
https://www.hificollective.co.uk/catalog/glasshouse-large-wooden-cone-feet-p-9728.html

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

as weird as it sounds, I cut drywall squares and secured them with sticky wood veneer.
the best anti-vibration solution.

I agree with stereo5, solid maple is an excellent turntable platform, the thicker the better.

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

Thanks Boxer12. I hadn't considered Corian.

Mike

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.  

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.

Thanks,

Mike

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

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