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
I came up with this tweak & have been using this tweak for many years.
Probably the best $500 tweak I could ever imagine.
I have 2 Adona 24" X 24" granite with mdf platforms that I used with Sonus Faber Stradavari's with great success.
I used the spikes with disc's that came with the speakers on the granite platforms.
http://www.paladinltd.net/System91906.jpg
#1 - It made positioning (moving) the speakers a very simple task. Once the spikes & disc's were set up on the granite platforms - toe in, toe out, a tad closer to the rear wall, side wall became a snap & now a one man job.
#2 - It allowed me to position the speakers 2' closer to the rear wall - which in my case opened up the soundstage big time.
#3 - The speakers (graphite) looked great atop the granite platforms & a perfect match for my 2 Adona racks.
*I did have to adjust/raise the rear spikes about 1" so the tweeter position was ear level.
**Do not use spikes under the granite platforms as it will kill #1 & place the tweeter even higher.
Granite works well in some cases but not always . Sandstone is the best , three inch thick and as wide and long as possible . I've used MDF filled with sand and lead too . Coupling a speaker to a wood floor that is not really solid with spikes can activate the floor , great for movies but not for music .