Mel,
Yep, my audio is poor also. Since calibration never completes, I turned off the predistortion. The audio is really poor if you turn off mic agc, then it is just loud noise transmitted. With agc, when you talk the noise is suppressed. I have not done much experimenting with compression and EQ as reported. My recollection is that with CESSB, you don't want to use compression.
Gary
W9TD
Gary W9TD