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?
call the company for best advice.
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.
#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 .
I have a much better idea that's works far better. I have gone down this road you are on and this next option works far better.

Get some Star Sound Sistrum platforms under your speakers and you will be amazed at the results. They come up used and work wonderfully.

The granite thing may look cool but the results are not as good. Sistrum improves focus, detail, separation of instruments, cures muddy bass lines, and let's the music flow out with improved clarity and fidelity.

They would be ideal under your speakers. I think the smaller 03 or 04's would fit. The larger SP1's may also work. Just look up the dimensions.

The granite did tighten up the bass, but did not do the other things mentioned above as well.
I have the same room conditions. I've used granite under my box speakers for 10+ years. The bass is much tighter. I tried Sound Anchor stands with my B&W 801 a few years ago and the granite performs better. I gotta get off my duff and sell them stands.
SYMPOSIUM SVELTE is much better natural,great bass, wide stage etc. Granite sounds like a rock very bad.HELLO!!
Be careful with that last post , the Symposium system works well with some speakers and awful with others , been there done that . Try before you by .
You could also try Boston Audio graphite tuneblocks either what they specifically intended for spiked components or their blocks with tangsten ball for electronics. I use the former with excellent results on wooden floor.
Thanks for all the responses. I am also considering Stillponts Ultra's, pricey but sound very effective
Off the thread a little but I suggest you move your speakers more into the room if you can.
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.
I see. Your room is very nice, and I don't just mean in terms of audio.
Thanks for the complement. We really enjoy it.
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.
Did you like the resulting sound?
HI all ! yes , it tightened up the bass a bunch and raised the speakers just a little...which was welcomed .