Matt, do you have the original midranges and salvaged ones, or are they the same drivers? Please provide some detailed pictures front and back, showing any labels or lettering. The TLS50 mid was an ELAC or EMI driver depending on version of speaker, and some earlier or later units used on the very early Studio or Compacts might be different or differently doped.
When did you get your speakers, and do you know when they may have been modified? Have you had a chance to recap them, because a bad cap in the midrange circuit could certainly affect the response.
Congrats Floyd15, when did you do the recap, how, and which caps did you use? Got Pics.
Folks, we'd all would like to see pictures of your IMFs so I'll post this reminder: