Sorry about this late posting, just saw it tonight. Looks like you're almost done experimenting so I'll throw something new into the fire and see what burns! An earlier posting mentioned Maple butcher block and I thought I had seen something in an audio site. At www.audionut.com, in "Products" and "Control Vibration" tabs, they carry a 1 3/4" x 17" x 12" maple board (doesn't look like butcher block) for $50 to be placed on top of your component(!). Hmmm!?! They are also carrying an isolation foot called the Aurios, which I first noticed this summer, that seem intriguing at the very least. Might be a b*tch with large power cords, as the feet have to balance in all directions and not "pull". Neither product has been tried by anyone I know, so FYI and have fun!
Shelf Material
I have tried so many different shelf materials, and some are better than others, but I feel like I am just spraying bullets that always miss the bulls-eye. So far, I cannot live with the brightness of glass, the ringing of marble or granite, the sluggishness of acrylic, the muddiness of mdf etc. Light and rigid seems better than heavy and dense - in that I can live with the downsides more easily. I use heavily constructed welded steel racks - spiked to the floor and upward spikes supporting the shelves - and I reckon this is right. I like the way bladder products get rid of the resonances that plague shelves, but find that the way they slow down the pace of the music is hard to accept. Does anyone have some answers on this?