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The A/V "rack" I use is made of birch plated press-wood.It is wide and the shelves are rather thin, which, I think, is nothing to help on the sonic side of things.
I do not wish to replace the whole thing because, for whichever reason, I happen to like it. But it would be nice to help it make my system better. Here is what I thought for a cheap upgrade :
My father in law has lots of wood-working equipment wich would allow me to laminate pieces of wood to make nice 1 1/2 inch thick slabs to slip under my integrated amp, CDplayer and TT. Doubled with vibrapods or other damping device, I think it would be pretty neat.
I would like to know what are your thoughts on this and which wood would be best for this project.
Follow Ups:
Just to throw in another recipe, mine DIYs are like this:
1/8 inch aluminum plate, 1/2" 5 ply plywood, 1" inch open cell medium density foam, 1/2" 7 ply plywood, 1/8" aluminum plate. The lower plate was drilled to hold points. I used arrow tips that go for $1 each.I'm into spartan "form follows function" so I put a couple of coats of oil stain on the ply and did not cover the sides.
I also do woodwork, but needed stability for a rack I built. I used MDF as the basis for the shelves, then put nice veneer over it. I did all sides in addition to the top and bottom. You could even edge band the sides if you wished. You can't tell it isn't wood and it is very stable.
A friend designed his rack and had it built from laminated MDF 1.5 inches thick. It is very good at absorbing vibration. Just be sure to use something between the MDF slabs and the wood shelves beneath to prevent chatter.
I will not use MDF.Only because this is a project I want to fully enjoy - and I enjoy wood.
When I listen to music, my main goal is to have fun doing it, but as I listen, I *see* my equipment and just for this once, I want it to look good (ain't I fancy?). I would not let this way of thinking dictate my equipment choice, but I figure it is not to bad in the case of a low cost week-end project!
I have been reading through the Asylum for most of the day now and here is where I am at in my reflection :
I want to go with a 1/4 inch Balsa plate covered (top and sides -- so the balsa would not be seen) by a inch or 1 1/2 inch thick wood (which?) slab. All that resting on Vibrapods or Isonodes (as a cheap yet working solution).
The first wo stages would then damp as the wood slab would isolate.
Doubled with a casing damping (sand bag? bluetack?) for the CDP, it should do it.
Your appearance concern is the same for either solution.Your choice boils down to mass and that relates to the compliance of the shelves and the isolation devices you choose. Putting a heavy component on a light platform is one good way to avoid introducing another mechanical time constant into the support system, but it makes your shelf resonances more important.
Damping the shelf resonances is difficult. One way to do this is to place the 1.5-inch slab of MDF on a layer of Deflex rubber (partsconneXion) directly on the shelf.
If you still don't like MDF, look in the off-price department stores (Marshall's, Ross) for end-grain butcher-block cutting boards. These are much less resonant than the typical across-grain boards.
I think you're on the right track - balsa was an excellent suggestion.Try a 1/4" balsa sandwich with open-cell foam (1/4" balsa, 1/4" foam core, 1/4" balsa again). Then veneer the whole thing with a nice cherry or something and spike it to the rack, rather than use vibrapods.
I've had great luck with DIY Symposium clones as a vibration sink. Just do a search here for the recipe.Another tack is to try the light & rigid approach and go with something like Ken Lyons' Neuance shelf. They're a great price for what they are & do, but you can try the philosophy for cheap by mocking up something out of corrugated cardboard or a multilayer sandwich of open-cell foam from the local craft store. Another cheap way to try this, assuming the size works for you, is to use a tabletop from one of IKEA's Lack tables.
Is veneered in wood, so it looks great and works great too. I cut down some of the thickness a bit for other reasong.Top layer is birch ply and sides are ash strips. The rest you don't see, so you don't realize it isn't wood inside.
An important parameter that has not been mentioned is to make sure that the veneer does not make contact with all of the layers. If the different layers contact each other, this somewhat defeats the purpose of constrained layer design. The newer Symposium platforms are made this way and I think it looks pretty good (see their website for details).
I would also like to skip veneer : I feel confident enough to build a big piece of wood that would then be planed, but not to assemble smaller pieces... I have done my share of bad wood assembly and I would like to live it to that.In the light of your much appreciated comments, I finally thought of this :
1/4 inch balsa -- a layer of Deflex rubber -- 1 1/4 inch or so of waxed (rather than varnished) mapple. Without veneer, the layers could be seen, but there is nothing here to hide. All of that on studs.
FYI, I'd use foam core or something like gatorboard (which Symposium uses). I think the use of rubber runs opposite to the light & rigid design school that recommends balsa.
All the better then : foamcore is easyer to find and less expansive.I though it might have been too rigid...
The rubber laminated in between the hardwood and the balsa would have been to avoid using vibracones or vibrapods. I suspect that with cones, balsa, foamcore and wood the assembly might lack something soft to pickup the lower frequency vibrations.
There must something I do not understand -- could youplease explain?
Hi remi,I'm standing on the shoulders of giants - many here, Jon, Chris, Ken, Steve, Dave, and others - have done a far better job of explaining resonance control and design than I can.
I encourage you to search the archives.
Generally, there are two schools of thought - heavy mass loading vs. light & rigid. I'd think mixing the two in one device would dilute the effectiveness of either.
As I understand it, the main idea behind the "light & rigid" approach is that all things vibrate; the trick is to not store any vibrational energy. Rubber can be an insulator of certain frequencies, but also a store for them as a heavy, compliant material. Think rubber ball. It's more the high-mass school of thought.
Foam core and like material (gatorboard, styrofoam, corrugated cardboard, etc.) is an insulator too, but because of its extremely low mass for the volume, air space, etc. it is NOT an effective store of vibrational energy. What vibration comes in is immediately dissipated through the material instead of stored or reflected.
This may sound silly and simplistic, and certainly only takes into account specific frequencies, but as a test try tapping on material to get a feel for it. I do that all the time - can't help it!
Tap on a thick piece of foam core. Listen to the sound. Put your hand next to where you tap and feel. Put your hand on the opposite side of where you tap and feel. Vary the pressure of the "feeling hand" (so to speak) to simulate different weight components. Do the same with rubber.
IME (YMMV, etc.), rubber's dead sounding and sucks the life out of music. Light & rigid keeps the pace and energy flowing while effectively isolating from external vibration.
That said, experiment and obey your ears! While general principles apply overall, specific applications vary and what works in one case doesn't in another.
That was longer than I intended when I started. I hope it helps!
I can't avoid bring up the isolation / dampening discussion :I thought of rubber (thin layer, not a block) as a dampenig material, dampenig being, as I see it, a first stage towards isolation. It would have not been close to the component, and part of an heavier isolation device (think of that thick wooden slab I intended to use as a top sheet).
You seem to think light : do you feel there is something "wrong" with the heavy way?
If I decided to go light, I would then go for a thin (1/2in.) hardwood plate laminated to a foam core layer, laminated to a thick balsa slab (1 1/2in.).
But then, taking in consideration that what I use as a rack is not sturdy as should be, should I use vibrapods or vibracones instead of very rigid studs?
Hey, I'm up for discussion - hopefully we'll each learn something.Oh, I agree, rubber does damp. I was unclear. I'm no physicist, but I think the way it does that is to absorb, store, and release vibration. Again, think rubber ball.
I guess most materials work that way.
The heavy mass school says the more mass, the more "sink" for the vibration.
The light & rigid school acknowledges that too and says the less mass, the less storage of vibration. Drop a piece of styrofoam and see what happens.
Both work. Neither is 'right' or 'wrong.' It's up to you in your application to decide what works best for you. For example, George Merrill of Merrill/AR turntable fame, advocated for high-mass 'table stands. Linn likes light & rigid Mana. Both are three-point spring suspended subchassis 'tables.
In my experience, both 'tables sound better on light & rigid platforms. The rigid is particularly important so as not to interact with an already springy suspension.
Then again, Redpoint, Teres, Galibier and non-suspended, high-mass TT designers recommend a giant block of machinist's granite or an active isolation platform like a Vibraplane.
Again, different approach, just as valid and effective. For example, my heavy McCormack DNA amp sounds best to my ears on a DIY Symposium platform - different approach and more akin to mass damped (though it's really constrained-layer) than light & rigid.
In your application, where the rack isn't as sturdy as it should be, I'd think adding yet more compliance via Vibrapods could only make matters worse. The sound would get less focused, less detailed, and muddier. Again, that's just my reasoning - your ears will tell you for sure.
What to do in your situation is a good question. If I were in your shoes, I'd tighten up the rack or no amount of other damping/isolation will work as effectively as it could. Using cables & turnbuckles to cross-brace is a very inexpensive (and light & rigid - ha!) way of doing that. Once that's done, I wouldn't try something heavy to sink the vibration on a lightweight rack - the vibration would have nowhere to go but the shelf. So, I'd again go light & rigid via some sort of DIY Nueance shelf - some balsa/foam/cardboard/veneer concoction.
this makes lots of sense!I have been dealing with new concepts alot during the few days and collected lots of information : I will now let it settle a bit.
*A priori*, I would indeed go for a light and rigid solution, especially, as you mentionned it, because of the flimsy rack and relativly light-weight components (more or less 15lbs).
I will work on this and let you know of the results.
You're welcome and happy to be of service. Let's hope your a posteriori experience validates the reasoning.Please do let us know how you make out, one way or the other.
I didn't mention it but that's the way I constructed my clones. Mine are glued top to bottom: birch ply, MDF, foamcore, MDF, Masonite. But the side overlays are only glued to the top layer of birch veneer, not to any of the layers below, which they don't touch so that the central layers are free to compress in this design.I'm not sure how well this compares to the original symposium shelving - probably not nearly 70% as effective. But it does work well enough in my system, and it uses wood and looks great, so WAF is higher.
Can you post a pic?
Wouldn't illustrate anything inside the cloned shelf, which is the important part. All you'd see would be dark red mahogany stained wood. That shows you nothing of importance, since you could do it any color you want yourself.
Use particle board. It's ugly, it disintegartes when it gets wet, and it is probably the best wood at absorbing sound, i.e., not resonating. Also, cut it so that no two sides are parallel. That will limit peak vibration amplitudes.
I picked up a product called "Real Wood Edging" at Home Depot. This stuff is made to dress up the edge of shelving. It was in the department where they have the Melanine shelving. The roll I bought is white birch which seems like it would take stain nicely.
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