Slate under speakers?

I think all of this is as the 'listener' believes it to be.

We're using different speakers, on differing sorts of finished flooring, and applying what we feel or hope will improve things.

I suspect any or all of the above concoctions could be the fix for non solid floors. BUT it seems a no brainer additional attention to those instances is required for better results.

I'd like very much to try a composite layering of Ebony, Mahogany, and granite, totaling under 2in. with the Mahogany on top and stone on the bottom.

Everytime I've used Mahogany wood block footers for devices, the tones gained more harmonic presence and naturalness. Ebony added definition and dimension without inducing artifacts in the upper end.... and Mass, always has a good effect for imaging but it can be too too enhancing and appear either brittle at the extremes or too bright. The two woods would attenuate such ringing as the stone resonates or 'rings'.

Why not then give it a go?

Duckets, gentlemen, just duckets. Pricing out that plan came to well over $250 for 18x18x?.

18x18 will span the 16 on center floor joists, just about regardless their spots. Which BTW, might well be one other consideration. Setting the weight onto the joists directly and not in between them. Thus allowing for better coupling. The added 25-40lbs of each plinth won't hurt much either.

Speckled shiny black, with Ebony and Red Mahog sandwidched atop it ought to please the eye.

02-05-10: Donjr
Zargon. I'm just theorizing. It seems to me that slate or granite would resonate, where as MDF or plywood would not. If I were using slate or granite, I would put it on high density foam and not a lot of it, to cut down on how much surface area is touching the carpet. If you're going from having your speakers spiked to the floor (coupled) to putting them on slate on top of the carpet (decoupled), you will surely notice a difference for the better. Not the best though. You've still got something very heavy and dense, condensing the carpet fibers and slightly coupling itself to the floor, especially because of how much surface area there is with a slab of slate or granite. Companies such as Aurelex have done extensive research on this subject and that's why their line of products for decoupling amps (isolation risers) have very little surface area that touches the floor, yet very large surface area for the amplifier up top. The reason this phenom of slate and granite started was the WAF factor.....really. That's how this all got started. Then everytime somone posted the question, people would reply "I use slabs of granite. It made a big difference and it looks great", and everyone started doing it. I'm not saying it's a bad solution for carpeted floors, but there's better out there IMHO.

naah! I don't you have all the info/the correct info on the use of slate for isolation.
Due to the crystalline structure of granite, granite does tend to ring (& marble also exhibits similar ringing) when suspended (as in a rack). That's why some racks (Adona comes to mind) sandwich the granite between layers of wood. That basically damps the ringing within granite. OTOH, I've found that if granite is placed directly on the carpet there is no ringing in the granite.
Slate, if you look at its crystalline structure, is a very good isolation material. The structure allows for sheer movement & that provides very good isolation. And, as far as I could tell, slate did not introduce any harshness to the sound. Plus, as you stated, it has very good WAF.
Yes, there are many other solutions to isolation (as you stated) but don't discount slate as much as you have.
It might be better for you to stop theorizing & get the material into your system & do some listening?

Being retired from research NOTHING has the density of slate. The lab countertops are usually slate so your balances and micrscopes don't drift from vibration. The tops are complety dead or vibration free. For my own spaekers (been building them for 40 years) I lined my subs with slate. The bass I get with 10" Focals is fantastic. Spiking on carpeting is a must!

i have been using slate and marble under my components for many years. under a turntable is a must. i must admit never thought of trying it under my speakers.