Granite and digital..

When granite is placed on top of air bladders or springs the presumed ringing of granite is minimized since the granite slab is isolated from the floor right along with the component. It is also fun to build dual layer mass-on-bladder/spring systems to increase isolation effectiveness. I spike the bottom granite slab AND the component on the top slab. Thicker is better since it will be stiffer and better resist bending forces.

I agree from experience--granite resonates if speakers and subs are close to your components.  I still have my amps and CDP on granite slabs but have solved the problem with footers I have made.  If you want the look of granite, just have some Corian pieces made---much more inert.  

I find granite fine. The granite slab must be isolated from the rack. Combination of cones and elastomeric products. Use your fingers to feel if the granite is vibrating. No vibration - no problem. If your not satisfied with your fingers simply put a teaspoon of salt or fine sand on the granite and play your music above the volume you like. Vibration shows up immediately. If you want to be more fanatical glue a piece of plywood or  mdf to the underside of the granite using a glue that will remain flexible to minimize all vibration. Don’t forget to further isolate from the granite and use mass as appropriate for the digital player. 2 pieces of 2.5 inches on a bladder is a no go; will just make you crazy/crazier. :). Cheers

Uh, that’s why it’s a good idea to isolate speakers and subs. Granite’s properties of high mass and stiffness are good for the sound. That’s why isolation platforms from the big boys oft come with granite top plates.

Remember/realize that geoffkait likes to spoof and drive members of this forum crazy with some of his fanciful non sense. Most comment that he seems ready for the loony bin; if not already strait jacket material :)