glass shelves under components?


I have a Bello stereo/TV stand for my components which are Muse nine sig DVD/CD player, Audio Note Soro SE amp. I have these on brass cones which sit on the glass shelves. The sound had an edge to it until I put some very thin rubber between the point of the cones and the shelf and the sound warmed up to an amazing degree.

My question is: where, on a sound quality list, does glass fall? I presume it is one of the worst materials you could have under your components, and something like wood works better, but this unit worked nicely with my TV etc. Can isolation devices overcome the sound I get to an even greater degree or should I buy a new shelf system?
128x128philjolet
I had a glass shelf rack at one time and on the advice of a friend tried a very simple solution that worked for me. I purchased some 12" bicycle inner tubes at Wal Mart, one for each component. I inflated them so they would slightly flex under the weight of each component and placed them between the shelf and component. Experiment with the amount of inflation and placement till the component sits level. It was ridiculously inexpensive and worked quite well.
Glass may look great but it creates many sonic problems.
Try putting a sound absorbent board under a unit. Very inexpensive is something that Tandy Leather carries. It is called 'Poundo Board'. A 12" x 24" piece sells for about $11.
While its clolor is red, it works wonders.
Do like I did, get some custom made acrylic shelves. 1/2" acrylic that is 19" x 20" ran about $210 total for 4 shelves. That's $55.00 each with a polished front edge. You could also get 3/4" thick, that ran about $70.00 per shelf. Inexpensive compared to some isolation devices that would have to be put under each component.