How to Adjust Volume Using 'amixer' (with examples)

The amixer command is an essential tool for managing audio settings on systems that utilize the ALSA (Advanced Linux Sound Architecture) sound card driver. This command-line mixer provides users with an efficient method to adjust audio levels, channel settings, and more directly from the terminal. It’s particularly useful for users who prefer or require terminal-based solutions for sound management, as well as for incorporation into scripts for automated audio adjustment.

Use case 1: Turn up the master volume by 10%

Code:

amixer -D pulse sset Master 10%+

Motivation:

There are several scenarios where one would want to increase the master volume by a specific percentage increment. For example, you might find your current audio output too soft, whether streaming a video, playing music, or during a video call, and seeking a quick way to boost the volume without navigating through a GUI interface. Adjusting the volume by a set increment like 10% enables precise control over sound levels, ensuring you reach your desired audio output without overshooting, which could potentially disturb others or lead to speaker distortion.

Explanation:

• amixer: This is the command-line utility you are utilizing to control the ALSA sound system’s mixer.
• -D pulse: This flag specifies the audio device you are targeting. ‘pulse’ refers to the PulseAudio sound server, which is commonly used in conjunction with ALSA on Linux systems.
• sset: Short for ‘set sound’, this subcommand indicates you intend to set a volume or sound level.
• Master: This specifies the channel you are adjusting. ‘Master’ refers to the overall main volume control for your audio device.
• 10%+: This syntax modifies the current volume level by adding 10% to it. The percentage allows you to define the volume change relative to the current level, rather than specifying an absolute value.

Example output:

Simple mixer control 'Master',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined 
  Playback channels: Mono
  Limits: Playback 0 - 65536
  Mono: Playback 45000 [69%] [on]

In this output, you’ll notice that the volume has been adjusted and the new percentage level is displayed, giving you instant feedback on the command’s effect.

Use case 2: Turn down the master volume by 10%

Code:

amixer -D pulse sset Master 10%-

Motivation:

Conversely, there are instances where lowering the volume is necessary, such as late at night when louder audio could disturb others or when you notice that the sound output becomes distorted at higher levels. It’s helpful for users in a transient environment where the audio intensity needs to be reduced with precision. Adjusting the volume by a percentage allows the user to decrement the sound gradually and evenly, preventing a jarring experience that could occur with more significant reductions.

Explanation:

• amixer: The command-line tool for controlling ALSA-related audio configurations.
• -D pulse: Indicates that the specified device for controlling sound is the PulseAudio interface.
• sset: Signifies that you desire to set or adjust sound levels.
• Master: The main volume control. Adjustments here affect the overall sound output of your device.
• 10%-: This decreases the current volume level by 10%, reducing the audio output in manageable steps.

Example output:

Simple mixer control 'Master',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined 
  Playback channels: Mono
  Limits: Playback 0 - 65536
  Mono: Playback 40000 [59%] [on]

With this output, you observe the volume has dropped by 10% from the previously set level, confirming the successful application of your volume adjustment.

Conclusion:

The amixer command is a highly efficient tool for managing audio settings directly through the command line on systems running ALSA. Understanding how to adjust the master volume with precision using the amixer command can significantly enhance your control over audio dynamics, whether you wish to increase or decrease the sound. These straightforward examples illustrate its practicality and the manner in which it becomes invaluable for minimalistic setups and automated scripting scenarios.