Granite under wood for better isolation?

Haven't tried on top of anything, but I have realized the benefit of having weight on some things. Like my speed controller, of all things. :-)

One approach that Thom Makris keeps mentioning is to attach some angle to the bottom of the granite with JB Weld and let the angle embed into the sand. Perhaps more work at getting the vibs down into the sand will make the granite work without the Stillpoints. Something to try this spring.

Tzh: As noted above, some say the best solution is to join the granite and mdf together, for example with epoxy. Since you already have granite, and mdf is so inexpensive, it would be easy for you to try this.

I may give that a try. I did try the granite under the MDF and still prefer the MDF alone so far.

I just got a new turntable which did not fit into my old cabinet so I set about building a new one and again the perennial question of what to make the support shelf out of? I thought about granite but it has its own frequency response so I wanted to find something more neutral. I asked around and was told ebony was as acoustically neutral as anything and plexiglass was equally as neutral.

This got me thinking as after we had had an outside deck built the contractor had left behind a supply of ipe or Brazillian cherry.This is a very dense wood not as dense as ebony but almost. (You can't get ebony anyway) So I made a frame out of 4 1/2" x 4 1/2" legs and 1 1/2"cross pieces. I laminated about 9 pieces of 3"x 2"to make the platform then made another platform of 3/4" thick ipe and betwen two levels each of rubber and cork alternately to make a platform 3 1/2" thick. I suspended this platform on four cushions of 1 1/2" x 1 1/2" cork 1/4" rubber and cork sandwiches. I also suspended the whole cabinet on larger versions of my cork/rubber sandwiches

This was great for a while and sounded phenomenal until the platforms started to warp. Everything went awry. What to do?

I decided now on plexiglass. Plexiglass has to be supported all around otherwise it will sag. So I purchased a couple of 1" sheets of plexiglass put 1/4" cork between them, but only around the periphery 1 1/2" wide and another layer of 1/4"cork 1 1/2" wide under the lower sheet of plexiglass. Set up my turntable again and I have to admit that it sounds even better. Every thing seems to float.

I don't know if that helps but I think the secret is in isolating each level as much as possible and I think my borders of cork helped do the trick. So if you have granite and then wood try and set up a neutral barrier.

I live in a very old wooden house (1730} so you can imagine the floors are rather bouncy and vibrations from footsteps and everything else can have an effect. But with this set up nothing moves. It seems to work.

Best regards

I have tried most methods mentioned and can only tell you that the 1" heavy granite slab with 1/4" cork and 1/4" rubberized pad purchased at a home craft store sandwiched with a 1" MFD board has done a great job eliminating all floor noise. depending where you finally rest the isolation platform might farther help to place it on a triangle vibrapod/cone or ceramic DH cone setup under the MDF as to the way I have achieved sonic details/dynamics with fantastic success and results.

I can guarantee that most of your very expense isolation platforms sold by companies to our hobby uses the same composites hidden in a laminated covering and market the finish which sells for 1000s of dollars.

Enjoy music!