Wow, some great ideas here. Replies to some posts:
Can't contact original owner (not the seller to me). He is no longer with us.
Anything involving spike removal is not feasible either logistically or it's beyond my capability or my unwillingness to make this a life commitment.
So how to deal with the spikes. They do not go through the carpet. Can I simply rest sharp spikes on granite or marble? Should I force them into a soft wood base? Should I try something like the Hush Puppies recommended above? Again, this is not about protecting the floor or carpet, it is how to stabilize the speakers that have spikes which can't be removed.
Thank you to everyone for your thoughts and suggestions.