In the sand box

Well my Grand daughter likes the sand box,next time I'll give her some old equipment to play with.

Years ago I built a sandbox isolator platform for the turntable system of an audiophile buddy. By then my turntable system was in storage (where it will remain forever, sadly), so couldn’t test the efficacy of this box. But my friend said it did wonders to cut down vibrations from footsteps, doors opening/closing, etc.

As a wood working project it was simplicity itself:

1 - Using furniture grade plywood (more layers/glued laminations than regular plywood), construct a box with bottom, 4 sides, and no top face. Dimensions in this case were 18" square with 6" sides

2 - Those 5 pieces must fit together tightly/precisely & be joined by glue + screws

3 - Carefully use a router to gently roll/bevel the upward facing edges of the 4 sides

4 - Using a separate piece of the same plywood, make a top element that is 1.5" to 2" smaller than the inside measurement (Length & Width) of the box. Use the router to smooth all 4 outside edges

5 - Situate the box in the desired location in the listening room (easy to do it now, near impossible after the next step)

6 - Fill the open-topped box with play sand, enough to come w/in 3/4" of the top of the sides

7 - Drop the top element onto the sand. Use a carpenter’s level to level the top element.

8 - Place the turntable on the top element (centered securely), then re-level.

That’s it. End of vibration reaching the TT via floors, walls

Why would someone want to use sand vs something like slate, concrete, or a solid polymer?

  I just visited Taleisin west of Madison, Wi, Frank Lloyd Wright home.  The base is sandstone boulders, not concrete, and they are raising money to jack the foundation, for the third time since it was built.  Now sandstone and sand are different, as is the requirement for stabilizing a large dwelling vs an audio component, but I do think that there is a lesson contained here.

I tried a 2 " thick piece of Granite from a sink cut out from a countertop under my turntable, it caused severe ringing and the sound in the room was terrible. Staying with the sponge hockey pucks.

I've tried many isolation schemes over the decades, I prefer sand boxes to granite, concrete, various woods, soft and hard plastic products.  The platform which sits on top of the sand is critical, I have platforms made of various thickness aluminum plates, all with vibration sinks attached via structural glue, also have various wood platforms, various thickness maple and baltic birch. Finally the footers, have many to choose from, generally prefer Stillpoints. Finally I have choice of avoiding sand boxes, platforms or footers altogether, components hung from custom built stands via high test monofilament fish line. All isolation solutions editorialize to some extent, the fish line method  editorializes the least. The entire system sits on a large concrete slab over a suspended floor which is reinforced with a number of floor jacks placed in strategic positions.