2. misc-audio
  3. 138518-118236

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
lowrider57's avatar
lowrider57
5,393 posts
 
@williewonka , I don't believe Sorbethane or rubber should ever touch the component or footer. It may be used as a layer between a platform or plinth and the shelf.

I'm familiar with that link and I'm a believer. Geoffkait has also provided many comments on the benefit of draining vibration, (Yes our Geoff really does know physics).
I took his advice a while back and ordered DH cones. I'm using them under my PWT transport and the sound is more open and detailed with no harshness. BDR Racing cones sounded harsh. 

So, I'm now sold on isolating all my components in this manner.
 

lowrider57's avatar
lowrider57
5,393 posts
 
Yes Steve, keep me posted.

What kind of steel ball bearing feet did you use? You’ve got me worried since I ordered some footers today on a close-out...
https://edensoundaudio.com/shop/terrastone-roller-bearing/

Maybe I should have stayed with cones.

williewonka
3,067 posts
 
@lowrider57  - many years ago when I first started looking into isolating my components I "created" my own low tech version of a foot using a steel washer and a hardened steel ball bearing - see...
http://image99.net/blog/files/0915f27ce41639dc6e4bf13bff2cbcbb-24.html

My thoughts were - I figured cone  anchors the component to the shelf, even if the small protective disks were used to prevent the spike digging into the shelf - whereas the ball is less prone to digging in.

It did a great job of isolating the component from the shelf, but a lousy job of draining vibration from the component, because of the sorbothane

Since I now use a piece of granite under the component, using  cone would have less tendency to dig in.
 
Fast forward to a couple of weeks ago when I started looking into "draining" and I thought - what if I remove the sorbothane and just used the washer/ball "foot" attached directly to the case of the component.

It does drain - e-v-e-r-y-t-h-i-n-g!

The resulting image was presented so far back behind the wall (i.e. behind the speakers ) it resulted in lower volume. I had to crank the amp to 1 o'clock (normally between 8 and 10 o/clock.) to bring the image back into the listening room But it was very detailed and crystal clear, it just sounded very far off. It also sounded quite "harsh" or "Brittle"

I found the wood cones have the same clarity and a warmer, but the image is more forward and as a result the listening level is back between  8-10 

I have also tried the washer with a glass marble - this is very much better than the steel ball - it does not have the harshness or image issues

The Terrastone looks as though the ball is either steel, brass or ceramic  (from the images on the web) - not sure what the body is made of though and cannot find any details - could be an alloy of some kind?

I've heard aluminum cones are very much like wood, but I have not tried any to date

Maplegate uses brass - like the Bear Paw,

I now have a guy turning some cones from brass and bronze in different sizes - fiigured I would give them a try, see which material provides the best sound.

Hope that helps - Steve
Post removed 
lowrider57's avatar
lowrider57
5,393 posts
 
@williewonka; cool website, I bookmarked it.
The Terrastone is a proprietary composite as are many of these offerings from specialty companies. They get good online user reviews and VPI recommends them as feet for their TT's.
   I don't know about the construction of the TerraStone Roller Bearing, but it is a brass ball. In a review it's compared to Symposium rollerblocks.
I will definitely report my results.

Regarding your footer design, Sorbothane is a substance which dampens vibration, but in your case, restricts the vibration from being drained. It also imparts its own colourations.
And I just re-read your post..
Then a fellow DIYer pointed out that the feet were not allowing internal vibrations from the transformer or airborn vibrations that might vibrate the cabinet, from being "drained" from the amp - he suggested I try brass cones or wood cones without any "cushion" material between them and the amp.
So, you already know this.

I know you're a DIY'er, but I've used some Herbies to protect the surface of the plinth w/o any audible side effects...
https://herbiesaudiolab.com/collections/system-isolation/products/thin-grungebuster-dots



More to discover