Client OS: Windows 11 x64 24H2, with Cumulative Update from 08.07.2025
3CX Client: Softphone: 5.1 BUILT 895 (Windows Store App)
3cx Server: V20U6 Final, with Debian
Error report: audio input devices in the 3CX Softphone Client.
We are experiencing an issue where the audio input and output devices in the 3CX app change sporadically. This means that the wrong microphone is suddenly set in the 3CX app, e.g. the notebook microphone instead of the headset microphone.
In principle, the 3CX app can store the default settings for audio devices. These work reliably in most cases.
However, the following behaviour occurs:
Whenever an audio device (e.g. a headset, Bluetooth or USB device) is connected, Windows recognises it correctly. As expected, the previously defined default device is automatically set as the default again when reconnecting.
The 3CX app offers the option of adopting this Windows default device as the primary device within the app.
In practice, this works without any problems for about five times.
After that, however, an incorrect assignment suddenly occurs in 3CX: The app recognises the same devices but sets a different one as the default, regardless of the Windows configuration, which continues to work correctly.
Reproduction:
Open the 3cx Softphone Audio Options
- Spanner symbol -> “Loudspeaker symbol”-> Audio options
- Move window to the right side.
Open the Windows audio options
- Right mouse button on the loudspeaker symbol in the taskbar -> Sound Settings
- Move the window to the left-hand side
Connecting the hardware:
Connect the headset (USB).
You will see that Windows recognises the headset as the default device.
3CX also recognises the headset as either 'Communications' or 'Default'. When you connect a device, you will also notice that the fields within the 3CX audio menu flash and flicker. The app scans for and assigns devices.
Now, remove the USB headset. After 3–5 seconds, you will see that the 3CX app suddenly assigns a different default device in the audio menu. Not 'Default' or 'Communications', but something else. This results in the microphone on the notebook being selected instead of the headset microphone when a call is made.
It does not appear to be possible to make a fixed assignment (default or communications) in the 3CX menu, as a dynamic management system operates in the background that cannot be controlled.
I consider this behaviour to be a bug.
Issue 2: Dynamic device changes, e.g. 'Microphone', are not possible during the lifetime of a call.
If the microphone is incorrectly assigned during a 3CX phone call, as described above, it cannot be changed during the call. You can change the setting. However, this only applies to the next call. Even if the microphone was changed during the call, you must end the call.
Changing the microphone will only work if you end the call and make it again.
Due to the incorrect assignment on the part of 3CX, changing the microphone dynamically during the call should be possible.
People usually recognise an issue with the audio and try to fix it during the call.
If you have notebooks, you will have at least two audio output and two audio input devices.
'Dynamic changing of audio input an output devices during call lifetime should be possible, like in Teams.'
I look forward to hearing from you.
3CX Client: Softphone: 5.1 BUILT 895 (Windows Store App)
3cx Server: V20U6 Final, with Debian
Error report: audio input devices in the 3CX Softphone Client.
We are experiencing an issue where the audio input and output devices in the 3CX app change sporadically. This means that the wrong microphone is suddenly set in the 3CX app, e.g. the notebook microphone instead of the headset microphone.
In principle, the 3CX app can store the default settings for audio devices. These work reliably in most cases.
However, the following behaviour occurs:
Whenever an audio device (e.g. a headset, Bluetooth or USB device) is connected, Windows recognises it correctly. As expected, the previously defined default device is automatically set as the default again when reconnecting.
The 3CX app offers the option of adopting this Windows default device as the primary device within the app.
In practice, this works without any problems for about five times.
After that, however, an incorrect assignment suddenly occurs in 3CX: The app recognises the same devices but sets a different one as the default, regardless of the Windows configuration, which continues to work correctly.
Reproduction:
Open the 3cx Softphone Audio Options
- Spanner symbol -> “Loudspeaker symbol”-> Audio options
- Move window to the right side.
Open the Windows audio options
- Right mouse button on the loudspeaker symbol in the taskbar -> Sound Settings
- Move the window to the left-hand side
Connecting the hardware:
Connect the headset (USB).
You will see that Windows recognises the headset as the default device.
3CX also recognises the headset as either 'Communications' or 'Default'. When you connect a device, you will also notice that the fields within the 3CX audio menu flash and flicker. The app scans for and assigns devices.
Now, remove the USB headset. After 3–5 seconds, you will see that the 3CX app suddenly assigns a different default device in the audio menu. Not 'Default' or 'Communications', but something else. This results in the microphone on the notebook being selected instead of the headset microphone when a call is made.
It does not appear to be possible to make a fixed assignment (default or communications) in the 3CX menu, as a dynamic management system operates in the background that cannot be controlled.
I consider this behaviour to be a bug.
Issue 2: Dynamic device changes, e.g. 'Microphone', are not possible during the lifetime of a call.
If the microphone is incorrectly assigned during a 3CX phone call, as described above, it cannot be changed during the call. You can change the setting. However, this only applies to the next call. Even if the microphone was changed during the call, you must end the call.
Changing the microphone will only work if you end the call and make it again.
Due to the incorrect assignment on the part of 3CX, changing the microphone dynamically during the call should be possible.
People usually recognise an issue with the audio and try to fix it during the call.
If you have notebooks, you will have at least two audio output and two audio input devices.
'Dynamic changing of audio input an output devices during call lifetime should be possible, like in Teams.'
I look forward to hearing from you.
