I'll repeat what Trey explained to me, hoping he'll jump in and correct me if I make a mistake.
The current production stock of 'KB 1.1 's' are manufactured in China under authority of Klipsch, and are only sold to Ubid for resale. I have no idea how 6th avenue got them unless they bought them from Ubid.
They are slightly different than the original 'KSB 1.1 's' in that they use a different driver for the horn and a slightly different crossover network (probably because of the new driver ?).
I recently bought some of these from Ubid because I got them for an extremely good price, but I can't tell you how they sound because I haven't even opened them, I am fighting with Ubid right now to get them to take these back. I feel it is false advertising because every single auction on Ubid states these are KSB's and not KB's . Consequently the half-million of these for auction on Ebay are most likely KB's because ubid is where they all get their stock. More false advertising.
I have KSB 3.1 's and 2.1 's in my second HT setup and really like the sound for the size, but I am not even interested in keeping the KB's.
Hope the info helps!