Adjusting PA calibration manually

It is possible to calibrate the duplex performance of the conference phone when it is connected to a PA system. The calibration level can be set automatically by the B179 device or adjusted manually to any value between 0 and 5 (0 being full duplex).
  • Increase the calibration if the other party experiences disturbing echo.

  • Decrease the calibration if the other party experiences low duplex, i.e. your voice is muted or clipped when the other party is speaking.


The position of the PA system’s microphones and speakers and the amplifier’s settings may affect full duplex performance.


  1. Select MENU > PA > CALIBRATION.

    AUTO is the default setting and is recommended in most cases. The figure shown in brackets ( ) is the measured calibration value.

  2. Select different levels and compare the audio quality to achieve your preferred setting.

Next Steps

Call someone and ask them to assess the effect(s) of any adjustment you make.