On carpet, one way I've found works really well: set the speaker (without the spikes of course) on a heavy piece of fabric (like a canvas drop cloth) which extends all around the base of the speaker abour 4 feet or so. It's then quite easy to pull cloth (and the speaker) across the rug in any direction.
On hard floors, you can place a (3' x 3' or so) piece of carpet sample upside down under the speaker and slide it around easily.
On hard floors, you can place a (3' x 3' or so) piece of carpet sample upside down under the speaker and slide it around easily.