Damping between shelves and sandbox

Whoa! That blows the dry sand theory all to hell. How about compressible fluids for the isolation? Oh, wait! We already have gas shocks and air springs!  And compressible metals! 🤗

@onhwy61 The thicker board is a bit wider than the sandbox, so I need to lift it a bit. It`s a really nice maple board, and I am satisfied with the sandbox, trying to keep the foundations. 
@bdp24 ASC`s solution looks good, I am going to contact them
@jab the surface is steady, it`s in a basement with concrete floor. The sandbox supposed to be a "sink" for the resonance coming from the TT. My integrated amp has it own sandbox also, but the board fits there.I found sand is -so far- the best solution for the base what fits my budget too. 
@millercarbon The mineral oil is going to do the job, good idea. What quantity you used for your box? I am considering between four footers, ASC or springs. I think it`s the best not to leave gap between the two boards or am I wrong?  I am keeping the board since it`s a really nice Shun Mook maple board, I really like it. I have tried granite, I think it was "ringing", but I guess I`ve messed up something. My phono stands on 5" MDF (6 layers glued and veneered) and thinking about to DIY it`s final sandbox soon. The bottom and the walls of the boxes are 2" MDF, but If I thought It would be good to upgrade later to real wood. Maybe I should drop the idea :) What footers would you use?
@geoffkait Would you set your springs in between two layers of maple? 
Thank you!

@geoffkait Would you set your springs in between two layers of maple?
Thank you!

>>>>Yes, that’s what my Promethean Base did for many years. Now with the smaller springs you can still place them between two layers of maple or directly under the component. If you use two layers of maple you should use cones under the component and cones under the lower layer of maple.

@millercarbon The mineral oil is going to do the job, good idea. What quantity you used for your box?

No idea. Too long ago. Just pour and mix, pour and mix. You're going for not even damp, just barely enough so the stuff holds a shape with no dust.

I am considering between four footers, ASC or springs. I think it`s the best not to leave gap between the two boards or am I wrong? 

Okay there's a couple things going on. One is the sand is adding mass and damping, but almost no stiffness. Its the board or whatever goes on top that gives the required stiffness. Otherwise without that its like sorbothane, horrible, sucks all the life out of the music.

Sand and mass stops most vibrations but not the highest amplitude lowest frequency ones. Springs will work for that. But springs bounce. So if you do have something like people stomping around you still need something to control the springs. They are at best just one more tool.

I am keeping the board since it`s a really nice Shun Mook maple board, I really like it.

Great. So keep it. I would suggest trying it laying directly on the sand. That way you get a little of the maple sound you like but not as much and with more slam and dynamics. But its all a balance. The more you try the more you will see.

I have tried granite, I think it was "ringing", but I guess I`ve messed up something.

No, you're right, it rings like a bell. Its awful. Mine is on packed sand inside a massive concrete sand box and that kills a lot of it. Tap it and instead of ringing its a short sharp 'tink'. Which is not as good as "tunk" but way better than "tinggg" which is what it does with no damping. Then there's multiple layers of BDR  and even so I have to use a couple different things between the granite and the BDR. Its a pretty good balance, super dynamic and detailed, and I have got it down to where no one ever even notices any ringing. In fact the verdict is "audiophile nirvana".  Read the last system comments. But that's the thing about striving for perfection. I would try something else if doing it today.

My phono stands on 5" MDF (6 layers glued and veneered) and thinking about to DIY it`s final sandbox soon. The bottom and the walls of the boxes are 2" MDF, but If I thought It would be good to upgrade later to real wood. Maybe I should drop the idea :) What footers would you use?

Yes I would drop the wood idea. Unless you really like it. Always do what you like, never mind anyone else. All the wood species I tried imparted a very characteristic sound. I tried them because other guys thought they sounded great. MDF has a much more neutral character. But then its also a tad less stiff, therefore a tad less dynamic. Always the trade-off. Anyway if you want it to look nice simply cover with real wood veneer. That's how these subs are finished, rosewood veneer. https://systems.audiogon.com/systems/8367 
Mine is from https://www.veneersupplies.com/categories/Raw__Wood__Veneer/Wood__Veneer__A__-__G/ and I used the one with adhesive backing. Cut, peel and stick! Could hardly be easier and looks terrific! 

(I know you could just scroll up for the link to my system. But someone complained about me posting links to my system. So now guess what? Even more links to my system.)

The springs don’t bounce, silly. The combination of springs and mass acts as a mechanical filter. You desperately need to head over to your local library and read up on mass-on-spring isolation, you know the same method of isolation that the project to detect gravity waves used. Gravity waves have amplitudes on the order of the diameter of a proton and frequencies that include very very low ones, so sand, oil, Sorbothane, carbon fiber cones, etc. won’t work to obtain the very great sensitivity of the detection system required. But springs will. The best isolation is provided when the ease of motion is the greatest. Ironic, huh?