O.K., Hornies, what do the impedance curves tell us about these vintage LE175's on various horns other than, in spite of saying "8 Ohms" on the foilcal, they're 16 Ohms by contemporary standards and 10 Ohms is the appropriate L-Pad to use with them?
1) Driver only
2) Driver on 1217-1290 "Potato Masher" horn
3) Driver on HL 91 horn/lens
Is that the driver resonance down there at 400 Hz?
What's the peak above 1 kHz, then?
What's the usable LF cutoff?
They're "loading" how low?
They've rolled off -3 dB at what frequency?
Anything else useful or important revealed here?
I can provide Fs and Fmin for each, if that's helpful....