Isolation Platform for my Sota Cosmos?

Peterayer, the suspension Fn on your tt is likely in the 1-3 Hz range. At least my Sota is around that. So you can maybe measure it with a stopwatch since it is slow enough. Just excite your plinth and try to count as many cycles as you can while running a stopwatch. Then just divide the no. of cycles you counted by the time on the stopwatch. What Geoffkait says is possible. If the Fn's of both the tt and the platform are the same, then they can excite each other and if they get 180 degrees out of phase, then be ready to catch your tt. :) When you excite your plinth by pushing down on it, just watch to see what the platform does. Maybe it is dampened so that it does not respond to the tt mass moving up and down.

The SME suspension towers are heavily damped, so pushing down on the plinth does not get it to oscillate. Likewise, the Vibraplane is fed by a compressor, so as soon as one corner is pushed down, the air bladders immediately fill up and so it does not oscillate either.

I have not tried to defeat the suspension of the SME and listened to it on the Vibraplane. I only compared the table with and without the Vibraplane, and it is better with the Vibraplane inflated. The motor controller isolated on the Vibraplane also makes quite a difference.

Thanks for your suggestions. BTW, I thought that if they are 180 degrees out of phase, they would cancel, and it is only when they are in phase that the cycles amplify to cause problems.

I suspect all is fine, because I have never seen either move and the sound has never been better. But I wonder if the isolation is redundant. I'm going to try to defeat the isolation on my the SME towers this weekend and give it a listen.

The Vibraplane and the VPI towers are almost certainly not tuned to the same resonant freq. The Vibraplane is most likely around 2.5 Hz in vertical, I suspect the VPI towers' resonant frequency is around 4 or 5 Hz, possibly higher. Even though the resonant frequencies are not equal the two systems can still interfere, when you consider the mass on spring device acts as low pass filter with attenuation characteristics analogous to electronic filter, E.g., 6 dB per octave. So they can still interfere.

Symposium Ultra Stealth stand top 24WX19L 8/10 mmaron@msn.com Email>

Symposium ulta Stealth 24WX19D $700.00 /mmaron@msn.com