Also interesting, making some case for spikes (suitably tested on a particular setup):
"By having spikes on the base of the stand (as illustrated in diagram 1) we allow the speaker stand to ‘grip’ the floor under the carpet. As a result, we can expect the spikes to reduce how much the speaker and stand wobble around, particularly at low frequencies. Unwanted vibrations or shaking of the speaker box and stand at low frequencies could then be reduced. By holding the speaker more firmly we may alter or assist its ability to radiate low frequencies. In addition, the floor may now act as a secondary radiator or medium to convey sound vibrations to the listener. Hence spikes under a stand may well have an effect we can sense, not because they “isolate” vibrations, but for precisely the opposite reason! To do so, however, they need to effectively penetrate through the carpet so the stand can grip the floor underneath.
What the above can’t tell us, of course, is whether any changes produced by such spikes will be judged to make the resulting sound “better” or “worse” – or even if the changes will be noticeable. That will be a matter of individual circumstances and the personal preferences of the listener. There are various reasons for this. One example is that, in some cases, the movement on the springy carpet might help damp out higher-frequency resonances in the stand more effectively than being gripped by the floor. Matter of circumstances which might be judged ‘best’ for changing the performance in the way the individual user might prefer."
https://www.audiomisc.co.uk/cones/speak.html