Audio quality when using Teams Townhall with rtmp-in.

Hi everyone

I have broadcast a live music (orchestra) concert using Teams Townhall with rtmp-in (using Blackmagic Design web presenter).

When I checked the archive recorded on Teams, I realized that the volume of the music is being ducked automatically. All my audio sources are mixed down with a professional digital mixer before streaming to Teams so basically they have a good balanced.

I have another back-up recorded data and it does not have the same problem, so i think it is caused by the algorithm of Teams, and even if I am using an external encoder??

Is there a method to fix this problem?

I have compared the data recorded by the external device and teams. The ducking is quite obvious.