Ubuntu – Volume mutes when set below ~20% 14.04

Parts of this answer comes from Setting microphone input volume using the command line?, placed here for your convenience.

Increase volume by 5%

amixer -D pulse sset Master 5%+

Decrease volume by 5%

amixer -D pulse sset Master 5%-

Set volume to 50%

amixer -D pulse sset Master 50%

If you are using ALSA, amixer can be helpful for your script programming.

When dropping the amixer --help command in a terminal you will see something like this:

Depending on your soundcard, levels may be different than mine, but you can use alsamixer in the terminal in order to check which levels and which features in your sound card you can call in a command to set the volume as you wish.

In my example, with my principal sound card (I have 2: the embedded and a PCI audio card), levels are from 0 to 100, this way I can change the volume of a desired input/output in my soundcard by dropping in a terminal the next command:

amixer -c 0 set Front 50DB 
amixer -c 0 set Front 64DB 

In the first command, the result will set the Front panel output to 78% level and the second one will set the Front panel output to 100% level.

In order to gather information related to your mixer controls, drop the amixer command with no parameters and you will get a list. Or indicate which audio device you wish to see a list of controls with amixer -c X (where "X" is the number of your audio device).

BTW: Remember that DB values are calculated logarithmically and not linearly.

Remember that this command allow you to control parameters on whatever sound device you are currently using.

Good luck!

^{Thanks so much! This helped me with my Arch/LXDE setup - the mute button xml that is recommended on the LXDE wiki mutes all of the channels in alsamixer and doesn't unmute them (at least not for my sound card).}

How I got it fixed:

I changed the XF86AudioMute command value to:

amixer -q -D pulse sset Master toggle