I’ve been having a problem getting my volume up/down/mute keys on my keyboard to do anything at all with the volume level of my Manjaro Linux computer.
After much research I came up with a solution that works for my computer, and I will document it here for my future reference and anyone else in the Linux world who needs this information.
Originally, on askUbuntu.com someone asked, “When I press the volume up/down keys on my keyboard, the volume changes too much. How can I make the step size smaller so that I have finer control?”
This topic was close to what I needed. In my case I needed the keyboard volume up/down/mute to do something to the sound. It wasn’t.
I found the solution way down in the discussion. This solved my problem and even after repeated reboots still works.

This easy solution works and does not require CCSM.

You will not have on-screen volume bar action when you use the keyboard shortcuts, but you will have however fine-grained volume control as you wish.

  1. System Settings > Keyboard > “Application Shortcuts” tab
  2. At the bottom click the “+ Add” button
  3. The “Shortcut Command” dialogue pops up. Where it says “Command” type
    amixer set Master 2%+

    Experiment with the percentages. You may ned to go more or less than 2% at a time. The “+” increases the volume by that amount.

  4. Assign a key or key combo: Select a shortcut and press the desired key on your keyboard (volume up).
  5. Click OK and follow step 1 -3 for each of the following two set of commands:
    Name: Volume Down
    Command: amixer set Master 3%-
    Name: Volume Mute
    Command: amixer set Master toggle

After this, when you use your keyboard volume controls you should have whatever volume increments you specified. You can always go back to the original behavior by disabling your custom shortcuts and re-enabling the premade ones in the “Sound and Media” category.