Heavy difficult to move speakers- how do you deal?

OP,

I would imagine it would be possible to put castors as there is a drilled out steel plate forming its bass for the steel points. , But to take such a spectacular speaker and then significantly compromise the sound quality  with castors would be a real shame. 

@ozzy62

I always have six sliders around… vinyl side for on carpet and carpet covering for wood floors.

But seldom have I ever needed them. I have the delivery guys put in approx position and they are simple to pivot and walk one corner at a time. My speakers are about 120 lbs and it is trivial and of no real work or stress to walk them to change positions slightly. I have a bad back.