If there was a way to work the Dually design into a 3x15 that would probably be ideal. I don't know what kind of impedance nightmares that would cause though. A 4x15 Dually would probably be too tall to load into most vehicles.
It will be delivered via drone to each show.
Dropped from the air it will be remote powered so that the air pushing from the speakers lets it land like a harrier.