Re Herbie's gliders.
I now have them under my big Thiel 3.7 speakers.
My speaker have sat without spikes on a shag carpet over a solid wood floor, and the bass response (and general sound) has been so even and seemingly perfect I've never bothered with spikes. (I remember trying spikes after a while of listening but they didn't do anything for the sound, and raised them higher than I wanted).
For various reasons I sometimes have to move my speakers around - even if to achieve different spatial or tonal balance effects as I desire.
I tried using some castor wheels under them - the shortest I could find - but it seemed to alter the sound to a bit too much upper bass richness (possibly, simply by raising the tweeter/woofer position higher, though it may also have changed some floor bounce characteristics).
Finally I discovered the Herbie's gliders and ordered the Giant Threaded Stud Glider. They just screw in the place of spikes and only raise the speaker something like 1/2 inch, which when the speaker is sinking into carpet a bit anyway, barely makes a difference. As to sonic benefits I thought *maybe* I heard some clearing up in the midrange...but I'm not remotely confident about that because it is far too arduous to take unscrew and screw in the gliders to compare. What I can say is that they make moving the speakers a breeze, whether over carpet or wood floor (sometimes I have to move them between rooms).
