Vibration control inside a cabinet

There are different densities of Sorbothane, the soft one will get down to 5hz but one needs to wrap it in Gladwrap before putting it under heavy equipment, otherwise it will spread over time.
I measured and listened  to both densities with a rare Shure frequency response test record under a non suspended turntable and the soft 10hz they sell on ebay, measured and sounded like it isolated just as good as the super-soft one. I say go the one on the eBay link I posted.

Cheers George 

Innocent question: if Sorbothane is really so great an isolator why don’t the big boys at LIGO use Sorbothane? Obviously something’s wrong somewhere. Now, it’s possible that in some density Sorbothane might, emphasis on the word "might", be used as a constrained layer damper. But there are better materials for that application. I suspect Sorbothane is best relegated to running shoes as it apparently is a decent shock absorber. Which as I pointed out before actually makes it a poor isolator. Besides Sorbothane sounds well, funky. It’s not open and natural sounding like competent isolation devices. As LIGO found out after 20 years of isolation system development, there’s really no substitute for good old mass-on-spring techniques. Besides mass on spring devices routinely get down to 3 Hz performance and can be as low as below 1 Hz. Accept no substitutes. Finally the suggestion that Sorbothane can isolate down to 5 Hz is patently absurd since nothing can provide 100% isolation at 5Hz. Isolation is always a low pass filter. Of Sorbothane could isolate to 5 Hz LIGO would be using it.

absurd since nothing can provide 100% isolation at 5Hz

Did I say total Isolation, NO!
And neither can anything else, there is airborne feed back from speakers that also comes into it short of putting the equipment in another room this is the hardest one to eliminate, also if you have tubes that are micro-phonic, then your up a creek without a paddle.

Cheers George

Geoffkait: "nothing can provide 100% isolation at 5Hz"

Georgehifi: "Did I say total Isolation, NO!"

Geoffkait: "So, what did you mean to say, 1% isolation? 10% isolation? That’s why it was misleading when you stated isolation down to 5 Hz. Capish?"

Georgehifi: "And neither can anything else, there is airborne feed back from speakers that also comes into it short of putting the equipment in another room this is the hardest one to eliminate, also if you have tubes that are micro-phonic, then your up a creek without a paddle."

Geoffkait: "Uh, one said anything else can provide 100% isolation at 5 Hz. Everybody knows almost all REAL isolation devices are low pass filters. Putting the equipment in another room is not going to be 100% effective since the entire building is shaking. Hel-loo! Furthermore, airborne vibration from most speakers doesn’t go down below 25 Hz, anyway, so you can forget about it. Besides all tubes are microphonic, even the ones marketed as "low microphonic." Hel-loo!"

geoff,,,,,, go and play with your "directional" AC mains fuses.


Cheers George