Instead of changing out spikes, could you just raise the speakers and stands onto a platform. I have wooden floors and to protect it, I put the speakers with their original spikes onto two granite slabs. Under the slabs, I use stick-um plastic or rubber feet to isolate the vibration from and to the floor. I bought two 1" thick granite slabs (check with kitchen countertop places, they have scrap granite countertops that they can cut to size for you, I paid $60 for two). In effect, you raise the speakers 1 inch without messing with the spikes. The granite slabs look nice too. You can even match your decors.
