Mine are stable on on hardwood or thin carpets, but I don't have any small kids or pets who might push them over (my wife and the housekeeper have been cautioned to never touch the speakers). The simplest option would be to cut a couple of pieces of mdf or plywood about four inches wider and deeper than the speakers, set these bases on the carpet, then set the speakers on the bases. If you have small kids the preferred way would be to make the bases, remove the feet from the speakers, then screw the bases to the speakers from underneath.