Personally I would not advise spikes. Why would you want to couple these speakers to a wood floor. In fact, with the mass of these speakers they are already more than adequately coupled. In my view you should want to isolate them from the floor, if anything, so you don't have to listen to the results of floor vibration any more than necesary. FWIW, I can't think of a single reason to couple speakers to a wall.
Now don't laugh too much at this suggestion, but you might consider using some hockey pucks and some felt pads on the bottoms of the pucks. That way you get some isolation and still have the ability to move your speakers about.
Now don't laugh too much at this suggestion, but you might consider using some hockey pucks and some felt pads on the bottoms of the pucks. That way you get some isolation and still have the ability to move your speakers about.