I indeed have my Merlin VSM-Millennium over spikes over a granite slab (cut from a piece of my kitchen countertop where the sink goes) over wooden floor. I put four plastic "stickum" feet under each slab to isolate the slab from the floor. Works well in my opinion. I had expected the sound to be edgy (and the Merlin can sound like that in some setup) but it is not so. Very clean, detailed sound yet not fatiguing. By the way, since the kitchen counter has a shiny side, I put the rough side up to the spikes provide good coupling with the slab.
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?