Raising Speakers

Experimentation has made it clear that my listening position is too high. Not wanting to cut the legs off my couch leaves the alternative of raising the speakers.

The speakers are sealed cabinet floor standers (Hales Revelation Three; dimensions are 11"x14.5"x40") and the lift needs to be ~2-3 inches, stable and preferably not impinge on the decor too much. The floor is padded wall-to-wall carpet over a concrete slab. Thinking it through there seems to be two basic options.

One possibility is using taller spikes/cones. Currently the stock 1.5" tall brass ones are installed. Is there such a thing as 4.5" spikes? If so, any idea what effect would a larger mass spike would have on the sound?

Using a platform made of either wood (probably maple) or granite is also an option. Comments on the qualities these materials might have on the sound would be appreciated. Also, would it be useful to spike the platform to the floor? How about spikes between the speaker and the platform (or not)?

I'm always willing to try something new, but hope to narrow things down somewhat before investing in potential solutions. As always, thanks in advance for the input.