Spike seems to be the prefer feet for the bottom of loudspeakers or stands. However, to my uneducated eyes in all manner of hifi religious believes they seem to be the chosen for mechanical reason then acoustic. After a bit of armchair research I comes up with these 2 articles of note. Jim Lesurf of University of St. Andrews provide a few more observations what they are really used for. [URL]http://www.st-and.demon.co.uk/AudioMisc/cones/speak.html[/URL] He seems to suggest what I have been thinking all along simply they are good for keeping the loudspeakers firmly on top of carpeted floors. Since they could be adjusted individually it is also easy to keep the column of speakers or speaker/stand assembly level and upright. Then having a small contact area allow for a fairly firm attactment without the need for glue, bolts or screws. If temporary physical attachment are prefered bluetak provide a cheap and easy solution. An article in UHF magazine suggest it is a good way to reduce low frequency to be propagated into the floors and annoying the hell out of the bottom dwellers. Link is provide below. See comment at the latter half for the article. [URL]http://www.uhfmag.com/Issue63/soundproofing.html[/URL] Experimenters could you place your upstair loudspeakers on spike and conform this observation? Might be a useful tip is it works.