Homemade floor protectors -- advice needed


Here's my situation: I have hardwood floors that I want to protect from my speakers' spikes. I could use those little support disks, but they're a pain when adjusting the speaker position (they move out of position, and then I poke holes in the floor). Instead, I was thinking of placing two stone "tablets" on the floor, and then putting the speakers on top of them. There's a shop nearby that will cut the stone to my specs, and then polish the sharp edges.

My question is, what kind of stone would work best? Granite, marble, or something else? And would some small rubber "feet" on the floor-side of the stone still allow the tablet to couple with the floor to reduce resonances further?

Any insights you can share would help!
stevenb
Spike those puppies to the floor. Back when I owned the wood floor I used the rubber caps that came with my speakers (KEF at the time) that fitted over the spikes; now that I rent I spike my stands right into the floor. Nobody but you and maybe the scullery maid is ever going to notice. Seriously, the concept of spikes is to present as small a surface area as possible to the resonating floor while the joint is jumping. Defeat that and you wind up with a compromise no matter what kinda composites you lay down beneath your nifty spikes. Life is short...go for the gusto!
I used some of the dedicated floor protectors for my spiked speakers stands on wood floors--I needed the extra heigth in addition to keeping the landlord happy. I left the plastic on the undersides so I could slide the speaker stands aroud for positioning (three-point). Coins worked well in the past too. No sonic differences I could tell though.
Those little saucers that come along with audio points are claimed by the manufacturer (via instrument measurements) to actually improve coupling, so are not supposed to degrade the effect. If you don't want to use those (agree that sometimes it is inconvenient) what I've done is to save those data CD's that come with AOL junk-mailings, & place them under the spikes so I can slide things around a bit until best placement is determined. After that I remove them from under the spikes leaving nothing underneath, or sometimes then installing the protective coupling saucers. Those junk CD's can also be sawed into smaller size pieces if necessary.
Linn makes floor protectors called "skeets", they are heavy metal discs with holes in the middle for spikes. They slide easily when you need them to, without scratching.