Vibration Isolation for equipment using granite?

All great replies. Thanks to all. I guess everything may have it's time and place, but no solution for all applications. To my ears my system does not suffer from any ringing or excess vibration issues to warrant tinkering, but each situation is different. I was just curious if his approach is justified. Now I can understand a heavy slab on top of a component, but with ventilation considerations that is probably not practical.

Back in the day when I had a TT...30 yrs ago! Yipes!

The room I had to work with was NG.  Second floor apt in a house.  I could easily overpower the room with bass and cause the TT to skip.  So, I got the brilliant idea to get some marble headstones (scraps) and have them cut to fit.  Two slabs ~19X20X3 inches.  I also happen to have some sorbothane ~1" that was used to isolate Avionic gear from jet "fighter" vibrations.  Interesting stuff, actually feels like human fat.  Very compliant and then not!

Fat story slim.  One slab on the bottom then sorbothane then other slab then TT.

It completely stopped the problem I was having.  Much to the angst of the landlord downstairs. 

YMMV.  Just one guys tale.

Regards,

barts

Great Thread... Absorbing it in with intense Vibration..Some really good info here.

I vastly prefer quartz countertop to granite, as being a mix of quartz and acrylic resin it has a much lower Q-factor than granite and greater density than wood - an 18X24 3cm slab clocks in at about 75lbs. Chosen from a local countertop fabricator boneyard, it was about $15 ft2 so $45 plus another $200 for finishing the edges. . Using 2" 70 Durometer Sorbothane feet from Amazon ($22.95 for 4) underneath, my 50+ lb VPI Prime Scout has no acoustic feedback issues. And since I didn't have footfall issues to begin with, I can't comment on those, other than to quote Newton's 2nd Law, F=ma or F/m=a. As mass increases, it takes more force to accelerate it. My rig is at 125Lbs and counting, so it takes a lot or force to excite it, and thats after the sorbothane has damped it. 

Granite used solely as a Sub Plinth will impact on the perception of the End Sound, but as has been mentioned not to all who have used it liking.

My experiences of using Granite, is that I have come to prefer it over other Stone as a Sub Plinth, it has been compared to Marble and Concrete.

Where it works best, is when used in a Sub Support configuration as a Tier in a assembly. I usually find Three Tiers with a selection of separator types works very well, and can be produced quite cheap, where the structure offers good impressions, which in my environment can impress similar to much more expensive sub support and footers.

If you really want to get the Best from a Single Tier Sub Plinth the material known widely as a Resin Impregnated Densified Wood, will be worthwhile investigating, as a material it is about the best there is.