Had my system packed up and decided to drag it out today.
I can only say that this configuration is absolutely punishing when driven by a SS amp and the bass is turned up slightly.
Standing next to this speaker while it is playing is quite an experience, both the physical presence and the sound. I moved it around my room till the bass locked in and it is actually scary how much SPL this speaker is putting out.
I think a large part of it is that all 8 drivers are aligned together vs. fighting each other, less nodes.
I have also noticed the drivers seem to be able to take more power like this. Perhaps having the transmission lines compressed together creates some sort of damping.

Corey