Configure Use of External Microphones Through Line-In Connection

A Poly Trio system paired with a Poly Trio VisualPro or Polycom RealPresence Group Series system can use external microphones connected to the 3.5 mm line-in connections on the video conferencing endpoints.

Once configured, the Trio system uses the connected external microphones as the system microphones during audio or video calls.


  1. Connect the external microphones to the 3.5 mm line-in connector on the Trio VisualPro or RealPresence Group Series system.
  2. Configure the following parameters in the Trio system: = "0" "TvOnly"
  3. On the Trio VisualPro or RealPresence Group Series system, go to Admin Settings > Audio/Video/Content > Audio > Audio Input > 3.5 mm and make the following changes:
    1. Set Audio Input Level to 5.
    2. Set Playback Options to Playback to Far Sites, Mute Controlled, Echo Cancelled.
    The system uses the external microphones for audio input.
  4. Optional: Go to Audio Input > Audio Meter and test the audio input from the external microphones.