Granite under wood for better isolation?

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!

Suspended tables will highly benefit from this application.

Reason is for the mere fact the suspended table truly has no plinth and get great support seating on rock solid hard platforms especially when suspended underneath the table with some cones.

Non-suspended tables on the other hand would not benefit from such a application and I would recommend a MDF board platform 2" in height box with a inserted cavity bladder such as a bicycle inner tube or fill the box with play sand sealed.

Again many company have manufactured same design application isolation platforms as mentioned for our hobby and have made tremendous amount of dollars marketing and then profiting big time on the finished products.

Enjoy music!

Wood colors the sound Granit rings try SYPMPOSIUM IS THE BEST!!

If you take a piece of granite (typically 18"x24" for a TT and at least 3/4" thick) and place it on a bed of sand (typically 3"-4" deep), and add a TT, the combination will way upwards of 30-50 lbs. I guarantee that tapping the granite with a hard object will produce no discernable ring. In fact in my case, such tapping is inaudible through the speakers on quiet passages. I suspect the same it true for bonding the granite with MDF. Try it.