Another good way for cases for the JBL 10 is to use parachute bags. They are the perfect size, offer scratch prevention and only cost around $13 apiece.
I don't use any covers because I am very careful with them. But, since they are a little awkward to carry without a case because of the set up for the handle in back makes them off balance, I got some black belt webbing from a boat supply store to make handles for them.
I cut them to the right length, used a solder gun to burn holes through the belt where the screws fit through. The burning keeps the belts from unraveling.
I then took the front piece off the speaker and lined them up with the two end, top screw holes. Then I just screwed the front piece back on, and you have perfectly balanced speakers for hauling around. You can easily carry both at once.
Also, for quick set up and tear down, I leave the patch and power cords plugged in and use velcro ties to secure them to the belt handles.
Scott