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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
skyscraper OP
831 posts
 
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
italian
126 posts
 
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.
slaw's avatar
slaw
21,863 posts
 
I think your question is misguided... You should be asking ..How can I isolate my TT shelf from my built-in's?
bdp24's avatar
bdp24
9,873 posts
 

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.

geoffkait's avatar
geoffkait
23,365 posts
 
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.
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