Using Granite under speakers


I am considering using slabs of granite under my Von Schwiekert VR4SR speakers which currently sit on spikes on discs on suspended wood floor. Have been reading that such arrangement as I have now can bleed bass into the floor and reduce bass impact and definition. Any one with experience with using granite like this? And do you then use spikes under the speakers directly onto the granite? How thick does the granite need to be for best effect?
Thanks
Joe
128x128gammajo
Inna
Thanks for the tip. I do move them out some when critical listening, but they are front ported and they image pretty well where they are. WSF comes in terms of leaving them out several feet.
Hi all ! I went to a place that makes marbel and granite countertops . They made me two for my speakers and one to put my amp on . Think I paid 20 or $25 for each slab . Oh , and they cut them to my specs and polished all but the bottoms.