I should have added, that my point is that you have to drive the
xformer with a z similar to what the mic capsule provides to make an
accuracte measuremnt. This is not easy to do since the Z of the ribbon
probably changes with frequency as it is also a coil. THe Z of the
ribbon may be very low at low frequencies and therefore the low freq
rollof that you measure may not realy happen when the xformer is driven
by the ribbon.


By the way, I should also have added I really applaud you for making
measurmets instead of just posint something like" the mic really had a
heavy solid sound to it after I made the change". Thanks