Based on what I read here, I did a little tweaking this afternoon. I have a pair of PSB Stratus Gold-i speakers. When I bought them last summer, they came with spikes and a set of little clear rubber buttons (sorbothane?) to use as feet. There were no directions on when/how to use what. At first I simply placed the speakers on the hardwood floor of the family room with neither spikes nor buttons. Sound was good (i.e., big upgrade from our old Klipsch KG-4's), but after a month, I realized the bass was a bit too boomy. So I glued on the rubber feet and noticed that the bass tightened up, thanks to less coupling with the floor. After reading the good word here about speaker vibration the light went on (Newton's 3rd law -- duh!) and I decided to try the spikes. To ensure domestic tranquility, I first went down to the woodshop and cut out a couple of rectangles of 1/2 inch birch plywood the size and shape of the speaker base plates. I scraped off the rubber buttons, screwed in the spikes, placed the plywood plates on the floor, and put the speakers on top of the plates. I pressed the top of the speaker cabinets down to drive the spikes into the plywood (about 3/16 inch -- I hate to imagine having done this to an oak floor!). Fired up the system -- ah delight! THe bass tightened up, the midrange is sweeter, and the system is more articulate. I asked my wife to audition the sound, and without prompting, agreed that the sound was more resolved, with greater presence, more engaging, and more of a feel of live performance. Bottom line: the spikes are staying. Next step, make a dressier pair of protective pads and stain to match the color of the oak floor.