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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.

Mike


skyscraper
kingrex
48 posts
 
The use of beads to isolate the plates was a pretty big gain in reducing internal and external noise transmission.  In my earlier models you can see a simple stack of acrylic on corian with 3 beads separating them.  The TT just sits on top.  It does more than you think.  Way before all that I just sat it on a sheet of 5/8 quality plywood.  My preamp still sits on just that. Plywood.  My DAC and server are on a piece of corian with my isolating bead on a square of corian on a piece of loose felt.  Not the sticky back type.  I got the corian as waste from a second ha d reuse shop.  The acrylic from tap plastic.  A drill press helps to make good holes, but clamp the 2 pieces together and just drill 3 holes strait through.  A small hole.  Them take a larger bit and dimple the hole a little larger to hold the bead.  If you screw up, reclamp it, drill another hole next to it. 
williewonka
1,826 posts
 
@lowrider57 - the difference between various woods depends on their grain. Oak has two common varieties white and red and while both are considered harwood they have very different properties.

I’ve forgotten which is which, but one of them is actually much more porous than the other and would result in resonance from airborne vibrations

For feet there are several good hardwoods to choose from - like ash, maple, beech ebony and rosewood, but again they have quite different properties.

The verdict is still out on man-made products

Problem with hardwoods used for shelving is they tend to resonate with a different frequencies. To prevent resonance you can glue two or more pieces together, but you have to clamp them tightly

An easier way to successfully eliminate most all of the vibrations, I have found that if you place a layer of drawer liner on the shelf and then something heavy on top of the drawer liner - I use a granite tile, but a butcher block will work, then the "sandwich" formed prevents a great deal of airborne vibrations from resonating.

Any type of plywood is not a great solution mainly because you do not know what woods have been used in their contruction. Solid wood is better, but more expensive.

Marine ply is perhaps better than most because it is well constructed with quality wood and very good glue.- but it is expensive

Hope that helps
bdp24's avatar
bdp24
4,908 posts
 
Actually, we DO know what wood Baltic Birch plywood is made from. Can you guess? ;-). It is the wood preferred by serious DIY speaker and subwoofer builders, and by a number who have made bases for their Thorens TD-124 tables (Art Dudley built his with BB). The 3/4"/19mm plywood is made of 13 very thin ply's, each ply cross-grain orientated relative to the ply on either side. Two pieces of BB with constrained layer damping between them makes a great shelf, turntable base, and/or speaker enclosure. 
lowrider57's avatar
lowrider57
3,018 posts
 
@williewonka, thanks for the info. I've been reading that the density of the wood is the main criteria for isolation and preventing transfer of vibration. As you stated, porous wood will result in resonances and less isolation.

I built a shelf for a heavy SS amp using finished ash from Lowes. I doubled it and used wood glue to create a 3 inch platform. I then used Herbies soft dots underneath.
   The wood looked beautiful, but was not very dense like maple. However, it had a nice tonal quality.
 
geoffkait's avatar
geoffkait
14,147 posts
 
Maple is a known good sounding wood for use as a platform. Yet it is not a particularly dense wood. It is a medium density wood. Mahogany is much denser, for example. One of the best Woods for sound, but not really for a platform, is Gabon ebony, a particularly dense wood and also very resonant. I think balsa would be interesting for a platform, a very thick slab of balsa.
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