(OT) Adding a ribbon tweeter to my speakers?

[voice of the theater]

There must still be a fixed pad of some type, no? as the 604 HF and LF sections don't have the same sensitivity.

Good point--there must be something in place to "tame" the higher efficiency of the horn as compared to the woofer.... Cradeldorf--do you have a schematic of your crossovers?