Sorry if reviving this thread is out of bounds, but I was reading back through about the Altec 755A. (And couldn't send a direct message)
Also, I've never read mentions of a field coil version before. Did it have a different model designation?
@GM, out of curiosity - what was your first/early exposure to them? - Monitoring in studios/radio transmission, voice PA, portable cinema installs? Given their wide application range (noted in their ads), I figured it could be a range of things! Did you develop a preference/use case for them (especially regarding cabinets)? (including any tweeter?)
Also, I've never read mentions of a field coil version before. Did it have a different model designation?