After some more testing and prototyping, we decided to go the foam surround on the F10 Select drivers as well. Not only does it have a little more efficiency, but it also has a very nice, richer midrange than before. It's definitely an improvement, so we'll be switching to the new design from now on.
Improved efficiency and improving the critically vital midrange region? How do you not appreciate and welcome that? The folks at Cube Audio definitely burn the midnight oil it certainly seems.
Charles