 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
205.188.116.141
Hello guys,
I just finished building a constrained layer damping shelf for my VPI TNT. It is about three inches thick, weighs about forty five pounds, and is composed of a combination of alternating layers of birch ply, corian, and thick rubberized fabrick flooring material. It is "veneered" with a 1/8" layer of black acrylic, all the way around, to match the TNT's plinth, and it is all glued together with silicone adhesive. I don't know how it will sound (yet), and I know there are a lot of different ideas about how to construct a shelf such as this, but it looks great (if I say so myself), and it seems to be inert as all get-out. I had a great time building it.
This shelf will replace the flimsy mdf shelf on a older style Target wall mounted tt platform; the one with the extra metal supports. The new shelf is, of course, much bigger than the stock shelf (19"X25"). So it will have to sit just above the frame of the platform, since it will not fit "inside" the frame of the Target platform as the stock shelf does. I will have to replace the upward facing "points" that the stock shelf sits on with longer points so that the new shelf sits above the frame of the Target platform. Here's the question:
Will it make any difference, given the weight and solidity and inertness of the new shelf, if instead of metal points, I use something like Myrtle wood cones, that I can have constructed, and fitted with threaded studs. I had hoped to use BDR cones/pucks, but BDR uses a different thread size. Any other thoughts/suggestions?
Thanks much.
Follow Ups:
given what the wall is attached to, and how many studs - the vertical timbers or steel tubes - you're actually bolting to.Laminated shelves can be very stiff and have very good self-damping too, but I would ask whether the new layered shelf was formed under pressure? - ie in a clamp or press or under weights or sand bags?! and, one layer at a time!?
It may also be a good deal more important - than the cones et al - to look at the shelf's attachment to the wall because a bit of compliance at those points may / may NOT help a great deal more than 'on the shelf' expenditure - IF the wall is /isn't itself rigid to earth.
How much do you know about the wall and its supporting structures!? and the earth it sits on.
Spending money on what people can see, on things on the shelf, rather than thinking about the wall as a part of your record player, isn't likely to give very high returns on investment aka ROI.
Why?
Because the issues I have raised are higher up in the order of things that matter.
Viz, my heavy concrete slab wall-mount shelf 36 x 18 x 3", on which the TT, preamp and CDP sit, does, very distinctly 'wobble' ~~~~~~ ! when trucks are in our street / when my sons open and close (aka slam) doors.
BUT, the rest of the time the set-up is completely unaffected by the speakers output, even at 'turn that down!!!' levels. The wobble is at about 3hz!
ALL TT's are low-pass filters to the ambient sound field they work in, IE they attenuate most audio frequencies above say 10/30 hz - more or less - but allow into their mechanisms the very low frequencies we would most wish to filter. yes, even suspended ones are low-pass filters.
IE they are not good at filtering incident ELF ( < 10 hz) sound waves.
ELF is NOT good for TT's!
But vinyl IS worth the the hassle.
;-)
Why can't you reduce the plan dimensions of the shelf?
Warmest
Timbo in Oz
The Skyptical Mensurer and Audio ScroungerAnd gladly would he learn and gladly teach - Chaucer. ;-)!
'Still not saluting.'
http://www.theanalogdept.com/tim_bailey.htm
Edits: 10/21/08
Thanks, crossman, for the link. I will let you know how it sounds when I finish setting the TNT up; waiting for an armboard for my ET2 from VPI. They drilled it incorrectly first time around. They have been beyond helpful, however.
Thanks for the great post, and very useful info, Tim.
I cannot reduce the size of the shelf because it is the exact size of the footprint of the VPI TNT. Yes, I did clamp the indidual layers of the shelf, one at a time. Wanted to make sure there were no air pockets in there. It really did turn out very well.
The Target wall mounted platform is attached to two very solid wood studs of a non-bearing wall on the second floor of my 110 year old townhouse. Very solid construction. The studs were almost impossible to drilll into, the wood is so dense. The wall is, however, one of the two "sleeves" of the two pocket doors into the room. It does vibrate when you knock on it. Not much I can do about this, as I am stuck with this location for the platform. The only alternative is on the rack on the floor, but I have terrible problems with skipping from footfalls. My gut feeling, based on experience with different footers, shelves, etc., was that I needed something fairly rigid (best sound, to my ears), but with some compliance (rubberized frabric/silicone), to deal with the previous propensity for induced feedback (at high volumes) with my previous table.
I should know in a week or so wether it worked or not.
Best.
Consider carbon fiber cones from Composite Products. I saw their stuff at RMAF and it was impressive.
Please let me know how your shelf works out. I have a TNT also and am using a Bright Star TNT Big Rock/Air Mass & just bought a VPI TNT stand . I now need something to put under the Bright Star base with the new stand.
Post a Followup:
| FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
||||||||||||||
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
