How Does disableAGC=true Query Option in the Meeting URL Works Exactly?

I am wondering how the config.disableAGC=true query option in the Jitsi Meet meeting URL works exaclty. I tried to find its official documentation, but I do not seem to be able to find any. It seems it can be a setting on the server side also, but that is not within the scope of this post because I do not expect to be able to install and run a Jitsi Meet server by myself any time soon.

I really need to know this because I keep suffering from my voice seemingly haphazardly going soft while I speak in a Jitsi Meet meeting. In the last public meeting I hosted with 10+ participants, my voice got soft repeatedly and randomly, e.g., this video at the 1:50 mark — my voice suddenly gets soft in 5 seconds. In another 15 seconds, someone tells me my voice is way too soft for them to hear.

I do believe I added #config.disableAGC=true to the URL when I joined as a moderator, but I am not 100% sure.

When I join a meeting that way, does that affect me only? Am I the only one who is supposed to be exempt from automatic gain control? Or is it supposed to affect every participant?

How to video conference in high-quality stereo using Jitsi Meet” has this to say about the URLs with audio-processing-configuring options:

Important: the instigator [= the one who joins with the URL with options] must join the room first, i.e. before all others using the simpler form of the URL [= the one with no options]. If anyone else not using these URL arguments gets there first, the normal Jitsi defaults will persist and stereo play back will not be possible.

Is this true? If it is, it means that the audio processing configuring options will have meeting-wide effects. And that should explain what I experienced recently — I tried to start a meeting but a guest had already started it.

If this is true, then I should be able to eliminate the voice-dropping-way-too-soft problem by making sure I am the very first one to start a meeting. Unfortunately, Jitsi Meet itself does not provide a feature to guarantee this, but at least I can kick everyone out if somebody has already started the meeting, terminate it, and then restart it with proper options.

Please advise me if I am on the right path or not. I have a feeling that I lost quite a few business prospects by looking unprofessional. I need to either take care of this now or find an alternative (most likely Zoom, as much as I hate the idea).

Thank you.


config.disableAGC=true affects your local audio capture only, and doesn’t affect anyone else in the meeting. There is no need to worry about whether you joined first.

This option disables the AGC algorithm running inside the browser’s WebRTC stack. Given that it’s the same algorithm for everybody, and this issue only affects you, I would suspect a hardware or microphone orientation problem and would expect this option to not solve your issue.

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Thanks, @jbg, for your resply. It seems I had completely wrong ideas about those options.

Hardware issues are probably unlikely, though. I use one of those neckband speakers from Sharp and it has worked reliably for many long (e.g., two hours or more) meetings with Zoom without a single issue. So my bet is the root cause is eleswhere.

Come to think of it, I have had this problem only when I injected audio into the call. I do not and actually cannot use the built-in feature of audio sharing in Jitsi Meet, because I need to keep showing a screen (a tab in my browser), and I need to play audio from a different app at the same time. On my Windows PC, I use Voicemeeter Banana for it. This setup has worked with Skype calls for years. Is it possible that audio routing by Voicemeeter and that by Jitsi Meet (for sharing audio from a Web page) interfere with each other?

When participants complain that my voice got suddenly soft, I mute myself and then unmute myself, which seems to solve the issue temporarily.

I undertstand that instead of using an elaborate setup by Voicemeeter, I can just share the whole desktop and share the whole system audio with Jitsi Meet alone, but I do not want to because I fear I might show something I shouldn’t — my desktop is an unholy mess.