Heavy difficult to move speakers- how do you deal?

few ways out:

1. find strong neighbor to help you

2. bulk yourself up at the gym

3. use dollies instead of casters (when you get help or bulk-up)

4. if you have space for forklift, you don't need strong neighbor or bulking up.

Make sure to cyro treat the casters and have them engineered for directionality. 

Wait! There might just be a new market opening up.

Tweaks that Roll, or Moving Tweaks. Caster Snake Oil. 

I really like what @lak said.  Most of mine have a place to screw in already.  But I am little weird about them sitting on casters from a purist standpoint.

use 3 of these

2" casters, need 3" height for dual layers of ball bearings

surface mounted top plate, use screws or two 1" x 2" ez pass strips

1" wide ezypass strips

2" x 4" clear, cut to fit

THERE ARE VERY SLIPPERY  SLIDERS OUT THERE - I HAVE 6  OF THESE UNDER MY DUNLAY 6 SPEAKERS (520LBS) AND I CAN MOVE THEM SORT OF ENOUGH TO GET TO THE CONNECTORS - THESE WOULD WORK GREAT UNDER LIGHTER SPEAKERS