Well, the light bulb is a waste as it mounts in the crossover. Plus it is a standard 1141 auto bulb (although it was almost too tight a fit when I replaced mine).
The horn driver is listed as a 8R 40 watt 1 inch driver HD1208R. (8R meaning 8 ohms.)
The woofer is listed as 12 inch 8R 350 watt prog neo speaker.
It appears the difference between the two revisions, A & B, is the crossover only.
Did you find the parts sheet on the Yorkville website? If not, I can email it to you. PM me here on it.
Yorkville is fairly responsive to email. I think they should be able to give you recommended high & low pass points for the components. You now have their listed wattage ratings.
I picked up a single NX20 on eBay several months back for monitor use. The guy probably thought is was bad because the light bulb was blown
It was listwed as functional
Wouldn't mind having another. Love the light weight.