Indeed.Originally Posted by Earl K
Notwithstanding wonky L-Pads, the adjustable wants to "see" 16 Ohms. With the 20-Ohm conjugate, an 8-Ohm series resistor accomplishes that. I don't understand why JBL used 20 Ohms between and 8-Ohm L-pad and and 8-Ohm driver in N3134/5.
In any case, adding that in stabilizes the L-pad (somewhat), and the new "input" impedance measures 6.3511 Ohms at 800 Hz (below).
For the record, I ran impedance curves on four LE85s on H91 horns. The one I have been using for these determinations is the red one (middle). It's not an "oddball."
For convenient comparision, I've reposted the WT2 impedance measurement on it immediately below the CLIO determination (bottom).
[I'd call them, uhmmm, "similar." ]