My pedestal thickness is 3/16, the height of my pedestal is slightly larger than 1/8", sometimes a little longer depending on the distance from the bottom of my playing surface, which is slightly larger than 1/8". The diameter of my pedestal is 1 5/8". I use glass over Corian or glass over glass. Try that and see if it makes a difference. I think your pedestal is too close to your playing surface. I've done that before and it was soo high pitch it wouldn't do anything except for kee kee and it was a slate.
TRKYHTR