Getting granite tomorrow.

Adding to my info. above I believe it will depend on the design of your actual speaker for end results, not all being equal.

I set up my TT stand in way descibed by Audiogalore and it works for me. 24X18 X 1 1/4 granite, 1 inch of cork, 1 1/2 inch rubber, 2 pieces 3/4 thick of MDF with sorbethane pucks. Bass deep and tight. No glare from highs. Also of note I turned up the gain from 42 to 52 on phono preamp and ran Adcom preamp in passive. That was a big difference too on the Shure 97xe. Having an SAS stylist come in next week. The Benz L2 was no slouch and conveyed more musical detail but the Shure tracks better and is a very very musical cartridge. The Benz was humming more and more and finally I had enough. Couldnt afford to get a 1K cartridge so I got the Shure for the time being. Some other members wrote they had negative experiences with granite. Maybe it just didnt blend in with their systems or maybe they didnt use enough dampening. Mike

It is only recently that I have experienced good isolation from vibration. I have spent at least 25 years exploring isolation devices, using bladders, spikes, mass, wood, cork, springs, like pole magnets, multiple layer shelves, carbon, and even active phase reversing electronics. I have sought to directly couple speakers with spikes all the way to decoupling them with gel. Everything had some benefits and some liabilities. Most could be heard to make a difference. None of these continued to impress me for very long.

The one device that has continued to impress me is the StillPoints new Ultra Stainless Steels and Ultra Five isolation feet, not the old cone devices. Basically these devices change vertical motion into horizontal motion and heat. The key thing is that you don't have to be concerned with where you want to take it. I no longer have concern with footfalls when playing vinyl and have great clarity and realistic sound stage.

Had problems with my suspended floor in the living room where music listening is done (wood with joists over a basement with carpet over the wood sub-floor). The bass excited the turntable, tonearm, and cartridge. The components are in a good rack with Stillpoints and other such isolation aids under all components. After many false starts with various "fixes", what worked is to allow my speakers' feet (not spikes) to sit on thick ceramic floor tiles with Vibrapods beneath the tiles. I had originally spiked the speakers to the sub-floor both over where the joists are and in between,neither worked. Getting rid of the spikes was key.

A few years ago, I hired a water-jet company to cut some slate slabs for me in order to make turntable plinths (for my own use, only). During one of my visits, I noted that they had stacks of very dense yet very light styrofoam-like slabs lying around, some about 3 inches thick and some about 5 inches thick. I use the term "styrofoam-like", because this stuff is much tougher than styrofoam and does not flake or fall apart, unlike the styrofoam we are used to. In fact, I use a handsaw to cut it. It's also black instead of white. They informed me that the stuff was packing material for heavy but fragile items that were sent to them for processing. They also invited me to take as much as I want. I am using it as an element of a vibration-absorbing structure under my SP10 Mk3. I would not claim that the net effect of my construct is superior to a Vibraplane or MinusK platform, but it works impressively well. (The Mk3 sits on 3 Stillpoints which ride on half-inch thick lucite plates that in turn sit atop the mystery packing material, which sits on a granite shelf dampened by a hardwood backing [an Adona shelf]. All of that sits on an Adona rack.) To give you an idea of the structural integrity of the packing material, it does not crush or bend in any way under the ~100-lb weight of the Mk3 in its slate and wood plinth. Yet each piece is "light as a feather", a favorable property; it would tend to dissipate energy, rather than storing it.