USB headphones get muted when setting volume below a certain threshold

Using a USB Headset (Microsoft LifeChat LX3000) with Unity's default volume control in Ubuntu 14.04 LTS, the speakers suddenly mute sound when I turn the system's main volume below a certain threshold. The threshold varies, but is about 25% to 33% of the scale available. I would expect sound to gradually become quieter and quieter until reaching the muted state at zero volume instead.

How can I get that (IMHO more intuitive) behaviour? What causes the early muting?

Solution 1:

I had a similar problem (albeit with a different headset) and found the solution here:

https://chrisjean.com/fix-for-usb-audio-is-too-loud-and-mutes-at-low-volume-in-ubuntu/

I recommend you follow the advice in the above link but I've copied the relevant sections in case the website or post disappears in the future.

1. Open a terminal (CTRL + ALT + T) and enter the following to create a backup copy of the original file before editing:

   sudo cp /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common_original
   

2. Edit the file in the text editor.

   gksu gedit /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common
   

   You'll be asked for your password - enter it and you should see a file editor pop up.

3. Find the section "[Element PCM]"

   [Element PCM]
   switch = mute
   volume = merge
   override-map.1 = all 
   override-map.2 = all-left,all-right
   

4. Modify that section so it looks like this:

   [Element PCM]
   switch = mute
   volume = ignore
   volume-limit = 0.01
   override-map.1 = all 
   override-map.2 = all-left,all-right
   

5. Save the final and enter the following in your terminal to reload the config:

   pulseaudio -k
   

Notes

• The number for volume-limit (in this example 0.01) might be too loud or quiet, change the value, save the file, reload the config and repeat until you're happy. Other values tested where 0.05 (too quiet), 0.075 and 0.5 (too loud).
• This is not my guide - but it resolved my issue and hopefully will help others.

Solution 2:

The accepted solution works but for me it muted system audio as well, so i had to revert.

I am on ubuntu 18.

I was just playing around and found that in the sound settings, under output devices, there were 3 devices:

and Analog output - USB PnP Sound Device was selected, i just selected the Digital one, and it solved my issue.

Any explanation of why it worked would be perfect addition to this answer.

It solved the issue for me, and when i unplug and plug headphones again, it still works and selects Digital Output by default.