I also couldn't really figure out the original description. If I understand the picture correctly it's a sort of tunnel of subs under the stage firing first under the drummer then out towards the front of the stage?
But then I can't make sense of the "assuming the cabs stood upright"-comment...??
Hi Frederik,
The "tunnel" description is about right, though from the OP I think there was one such setup each side of the stage rather than a single central one.
My comment about the cabinets being upright was in reference to the fact that I only show one driver in each as if you were loking down on a 2x18 from the top - just because it was quicker to sketch up that way rather than doubling the number of drivers per box in the pic.
Cheers,
David.