Pretty much what Adrian said.

I do use spikes but i don't have hardwoods under my Axioms (carpet then pad then concrete). It helps to level the speakers on the carpet.

That being said, our main floor has hardwood and the Tannoys don't have rubber feet so i cut shapes of spare carpet to slip underneath the speakers, which quite ironically are also used to balance them on the floor.
"Those who preach the myths of audio are ignorant of truth."