I've been experimenting with 1 1/4" polished granite slabs under my Genesis V speakers on a rug over a suspended wood floor. I have tried using DH cones and Pulsar points with and without the granite. Right now I'm back to just the granite slabs (24"x24") and think this sounds the best, with tightened bass response and improved detail and image focus (maybe w/ the cones the speakers are raised to high???). Haven't noticed any 'ringing' that some have commented on. If anything, it's smoother. Hope this helps.
Granite Under Speakers Over A Wood Floor
I would Like to use something over my wood floor that would not scratch it like the spikes do. I remember seeing sonus farber speakers on granite blocks. Does anyone have any experience with this? How would this sound?