I'm curious about that one myself(being a 3" driver")...
But "plain high school physics" dictates the more driver area you have...the more sound you can produce.
Cause Orb uses a 3" full range driver, although calling it "full range" is a bit disingenuous(because of its size)...
Other companies employing a single full range in some of their speakers...
Zu Audio
Ohm Walsh
There is even a website dedicated to the wondrous sound a single driver speaker...