Heard a pair of these at a listening party over the weekend and I was QUITE impressed
with the sound and the dynamics of the system! They look big and heavy -
but were amazingly efficient 101db!) and played quite loud with a low power tube amp!
Apparently they are a 2 1/2 way system?
There is a helper woofer, and the concentric driver -
a woofer with a blue foam-edged thats got a 2425 driver behind it.
I gather the "concentric driver" is an 801c
and the other "helper woofer" is a 2215H.
I found brochures for them here:
http://www.jblproservice.com/pdf/vintage jbl-urei electronics/urei-813.pdf
and here:
http://thehistoryofrecording.com/Man...5C_Manuals.pdf