I believe it was Timrhu, from the community here, who gave me a very good idea once how to protect wood floors from damage. it may work for you in this case to lower the speakers. He suggested I find carriage bolts (with the rounded head) and use them inserted where the spikes would be. One can take a bit of funtiture felt (for protecting floors, the kind with an adhesive backing) and put it on the head of the carriage bolt. Worked perfectly! In your case it would lower the speaker and still get them off the floor.
