You are perfectly correct as far as that goes, Cdc - and that's just the problem, when it comes to springy suspended wooden floors. Many speaker manufactures will specify in their owner's manuals that the spikes should be omitted in cases like this. Rigid coupling of the speaker to a non-resonant substrate, such as a poured concrete foundation underlying a carpeted first-level floor, is of course the ideal situation. But when it comes to a flexible, resonant floor like the one Marakanetz seems to be cursed with, attempting to break the mechanical coupling is about all one can try to do, as it will sound better this way even if it means the speakers are then not quite as rigidly positionally fixed in space while the music plays (which they wouldn't entirely be anyway, if the floor they were fixed to was flexing along). You do not want this type of floor acting like the soundboard of an acoustic stringed instrument, with the speaker's drivers as the strings, and the cabinet spikes as the bridge. You've got to attempt to "float" the speaker in this case, at least with near-full range floorstanders . (In my old apartment [and it was literally old], I used to fantasize about rigging up some kind of hanging cable harness to suspend my floorstanding speakers from the ceiling! Lucky me, now that I have the system set up in my new digs on a foundational substrate - when I finally decide on my speakers' ultimate positioning, I'll even be able to actually use my spikes!)