What is a good base for speakers

Fussing with setting up a new system in basement. My vintage ADS L710's sit on original stands that don't have fittings for spikes. As the stands sit on a carpeted floor, they rock a lot (no pun intended). I'm thinking of some sort of base to settle them down. Looking for suggestions of a material appropriate for stability  - any experience with wood butcher block, granite or slate cutting boards as a base? More DIY than expensive. Thanks for any suggestions. 
I bought two of these cutting boards, marked and drilled 5/16 holes at the four corners inside of the drip rail.  Screw in threaded inserts and then the cone points.  Flip over and the bottom surface is now the top and is completely smooth edge to edge.  Set them in living room with a level on top of them, adjusted until dead level and tightened the locking jam collars.  No matter what speakers I put on top, floorstander or stand mount, spiked or decoupled, they have a plenty large enough base to work from and always level.  I needed to compensate for an un-level subfloor as well as gain a few inches in height because of my listening chair.  Roughly $100 all in, look pretty decent and perform well for the investment.


What you need is to keep the speakers from moving in the direction of what the drivers are moving, so that the drivers can push air without the cabinet fighting it. I believe the ADS are front firing drivers, which means you need to keep the cabinets to be kept still in the fore-aft direction, mainly. Of course it's better to eliminate motion in all directions. 

As for carpet below the stands, its best to increase mass at the base of the stands, and use something with spikes (below the stand) that penetrate the carpet and padding to mechanically couple the stand directly to the floor (wood or concrete). This hopefully eliminates the carpet/pad spring that otherwise allows the speaker to bounce or rock.

After that, you can consider stiffening the stands so it doesn't bend.
I use Deer Creek Audio steel speaker stands like these:

The focus, stability and exactness of images is top notch, despite the fact the speakers rest on felt pads affixed to areas of the steel base.

All the best,