Nick,
About two years ago I built a sandbox. The result was not encouraging. The sound got dry and constricted. The material underneath the box did not seem to affect this behaviour.
Of course the result is system dependent, but, in my case, I gave up the sandbox and returned to the ceraballs which produced a far more effective result.
Also tried Granite slabs (with or without cork sheets), bubble-wrap and did not liked the result also.
The CDP then was a Meridan 508.24
Vermeer
About two years ago I built a sandbox. The result was not encouraging. The sound got dry and constricted. The material underneath the box did not seem to affect this behaviour.
Of course the result is system dependent, but, in my case, I gave up the sandbox and returned to the ceraballs which produced a far more effective result.
Also tried Granite slabs (with or without cork sheets), bubble-wrap and did not liked the result also.
The CDP then was a Meridan 508.24
Vermeer