Mapleshade boards under speakers

Late, as always- but I will offer my experience with maple stands, that echoes Thorman's.
No matter what combination of maple stands, mapleshade cones, and various elastic materials I used, the results were pretty much the same- dullness, smearing, loss of dertails and dynamics.
I've also had a few conversatons with some designers/ manufacturers of the support systems, who basically confirmed my empirical findings.
All had changed, when I switched to Sistrum platforms- without going into much detail, very significant improvements across the whole spectrum of audiophile virtues.
To oversimplify this approach- speakers need to be on a kind of support system, that can drain vibrations away from the speaker, and not to "isolate" speaker from external vibrations.

There are definetely fans of all different kinds of support systems. In my personal experience, that I shared above, I've found maple NOT having any positive effects on my system. That is not to say it didn't change the sound, it did, and not to the better. But I can see, where someone might like that change. You are right, this issue is room and system dependent, but again, I have a distinct feeling, that maple is NOT a way to go. Hence only positive comments from the users of Sistrum, SRA and HRS support systems.

My floor is carpet over concrete.

Emailists,
As a user of Sistrum and maple platforms, I don't feel they use the same philosophy- maple has (as everything else) it's own resonance freguency, and instead os "draining" vibrations away from the supported component, they "accumulate" that energy, and then release it back ( approx. the same, as the speakers cabinets do, causing "smearing" of the sound).
Sistrum on the other hand do not store energy, because of the different properties of steel vs. wood, and do release the energy into the integrated metal cones.
Under the speakers, in particular, maple on brass cones absolutely "killed" the sound, robbed it of definition, energy and dynamics. Herbies products in the same application, were even worse.