Look up "symposium clone" and "constrained layer"

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Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

Posted by bartc (A) on April 27, 2010 at 19:14:28

In Reply to: RE: Some old pix just to get you started posted by mschlack on April 27, 2010 at 18:37:13:

You have the general idea, but it can be done much better than that. Look up the clone ideas here on Tweaks.

You need layers of different density materials from hard on outer sides moving to increasingly "compliant" in the center. So if you look at a Symposium shelf you'll see from the outside (both sides) in: hard aluminum, MDF or birch ply, gatorboard or foamcore layers. That's the idea. I made mine cheaply enough with outer top surface of birch ply, then MDF, then 3 layers of ordinary foamcore (art store stock), then MDF then hardboard (Masonite) on the bottom. Mine are varied because of cost of aluminum and desire to show wood like surface, which I finish as stained wood.

The key to constrained layer sandwiches is that they need to be free to squish together (crude explanation), to move into one another, so your sides, if you have sides, cannot be glued to any but the top or the bottom layer. That allows the proper movement. They act as a seismic sink or isolator, where at each different layer interface they convert vibrational energy to heat energy.

But if you don't want to mock up one of these, and they're cheap to do to test the theory, then just buy some 1/2" thick or thicker birch plywood. It's not as good, but it is better than most solid woods. Solid woods are more tone woods, that is, you're deliberately using their resonant character and native resonant frequencies to "round out" your sonic picture. It's a different idea/mechanism, but it too can work.

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Follow Ups Full Thread

Topic - Building a rack and need vibe iso advice - mschlack 14:57:50 04/25/10 (13)

RE: Building a rack and need vibe iso advice - RioTubes 06:07:15 04/29/10 (0)

RE: Building a rack and need vibe iso advice - zanash 23:41:01 04/28/10 (0)

RE: Building a rack and need vibe iso advice - hahax@verizon.net 20:50:15 04/25/10 (3)

The jury is still out on spiking speakers to the floor - dave c 04:46:16 04/26/10 (2)

RE: The jury is still out on spiking speakers to the floor - hahax@verizon.net 20:22:55 04/26/10 (0)

RE: "Whereas the effect of the speaker cone moving the cabinet is absolutely tiny." - Paul_A 05:15:25 04/26/10 (0)

Some suggestions - bartc 20:19:55 04/25/10 (5)

RE: Some suggestions - mschlack 15:08:05 04/27/10 (4)

Some old pix just to get you started - bartc 18:01:43 04/27/10 (3)

RE: Some old pix just to get you started - mschlack 18:37:13 04/27/10 (2)

Note -edited for clarification - bartc 06:02:42 04/28/10 (0)

Look up "symposium clone" and "constrained layer" - bartc 19:14:28 04/27/10 (0)

RE: Building a rack and need vibe iso advice - Paul_A 17:23:32 04/25/10 (0)

Follow Ups

Look up "symposium clone" and "constrained layer" - bartc 19:14:28 04/27/10 (0)

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