Speaker vibration isolation

I too believed that coupling (spiking) them through the carpet to the slab would be the way to go...until it wasn't.

If it was a proper building slab of concrete some 2ft thick around the edge and some 6'-8" thick for the rest, if this wasn't best, then something else is at play.
https://s.hswstatic.com/gif/house-slab.gif

Cheers George

I feel it’s only fair to interject that whilst cement slabs do have their advantages they are nevertheless subject to the very low frequency vibration produced by the motion of the Earth’s crust, which pushes the cement slab just a tad. That is why mass on spring isolation is effective on cement slabs.

So, if I am to understand the dialogue, Martin Logans currently spiked to suspended wooden floors should benefit by a decoupling agent like the Giai 2. Right?

Typo: Gaia 

I would image dipoles do not produce much downward force compared with box speakers, thus reducing or maybe eliminating feedback problems. Whether dipoles benefit from isolation themselves, color me skeptical.