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TT on Symposium Super Segue - slate or maple underneath?

I've gotten a Super Segue for my VPI Avenger. I have various things on hand I can place under the Symposium. I wasn't sure if a 3" thick maple block would work better than a 1/2" thick piece of slate. The whole thing will be sitting on top of my wooden equipment rack. I know ideally I should try both to see what sounds better, but hauling a 70+ pound TT on and off shelves for listening tests (not to mention moving a 3" thick maple block around) can be a bit of a pain. I'm hoping someone here has had some experience with what they've felt works best under a Segue, so I could try that first.
tonyptony
tonyptony OP
614 posts
 

the component on the iso stand should be placed on very hard cones AND the stand or anything under the stand should also be placed on very hard cones.


@geoffkait, yes I can see that as being a logical approach. But the Symposium concept, if I understand it correctly, is to dissipate the energy transmitted from the TT / motor into the Symposium material solution,  mitigating the need to use hard cone materials to act as a direct drain for the vibrational energy into the contacted surface. It seems like a one vs the other approach - dissipation vs. directed coupling. If (IF) the couplers and pods act successfully to dissipate the energy from the TT before it hits a lower platform, I'm wondering now if that would be enough? I reread Shannon Dickson's Stereophile article (I had forgotten about it - thanks bdp24). His case seems to recommend pure isolation between the device and the lower supporting platform, through the use of a Vibraplane or similar. I know the bottom line is experimentation will be in order - I guess I was hoping to trim some options off the list to maybe make it easier.

But after years of being here, I'll admit Shannon and guys like you here with your background probably know a lot more about this stuff than me. :-)

geoffkait's avatar
geoffkait
23,365 posts
 
The seismic energy is not totally eliminated by devices since they are mechanical filters. So, cones are desired to prevent energy from being stored in the system, whatever that system is. Does the Symposium deal with seismic vibration? Maybe it does, but they don’t seem to address seismic vibration, so who knows? It should, since seismic vibrations are worse for the sound than induced energy.  Seismic vibration in the range 8-12 Hz excite the Fn of the tonearm, cartridge and platter.  In any case, what is required for best results is a comprehensive program of mass-on-spring vibration isolation AND energy dissipation/damping.
tonyptony OP
614 posts
 
Is thermal dissipation the same as storage?
geoffkait's avatar
geoffkait
23,365 posts
 
It’s the opposite. 
bdp24's avatar
bdp24
9,487 posts
 

Geoff, the Symposium system is a trio of their Rollerblocks under the turntable (which provides isolation in all planes but the vertical), sitting on top of their Segue shelf (which is an outer skin of stainless steel with a center layer of foam. My concern with the Segue is that I'm not sure the stainless steel is thick/stiff enough), the Segue having five springs on it's underside (there's your vertical isolation).

I'm going into Crosscut Hardwoods in Portland today, to look at their birch and maple plywood. They have it in 1/4, 3/6, 1/2, 3/4, and 1" sheets, in both 4' x 8' and 5' x 5', with plies numbering from 3 to 18 (depending on thickness). Cut into shelves, with two of them having constrained-layer damping between them, should make (with roller bearings) for a killer isolation platform. Stiffer, a higher resonant frequency, and more non-resonant than a simple maple block.

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