With firmware 188.8.131.52 (3CX) we are no longer able to set the microphone volume by vol_headset_mic and vol_handset_mic. The only adjustable parameters for mic are handset_agc and headset_agc.
With agc enabled the microphones are too sensitive. With agc disabled the agents are way too quiet for our customers.
So could you please provide these two paramters in the next releases?
we're working on this in order to reintroduce the manual gain tuning.
At this moment we don't have en ETA.