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ALSA Mixer

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AlsaMixer is one of the least deceptive of the volume control apps available on DICE. However operating it is still not entirely straightforward.

Launch AlsaMixer using $ alsamixer. This starts the mixer with your default ALSA sound card. You'll see something like the following:

┌─────────[AlsaMixer v1.0.17 (Press Escape to quit)]─────────┐
│ Card: Intel ICH7                                           │
│ Chip: Analog Devices AD1981B                               │
│ View: [Playback] Capture  All                              │
│ Item: Master [dB gain=-12.00, -12.00]                      │
│                                                            │
│    ┌──┐     ┌──┐      ┌──┐               ┌──┐     ┌──┐     │
│    │  │     │  │      │  │               │  │     │  │     │
│    │  │     │  │      │  │               │  │     │  │     │
│    │  │     │  │      │  │               │  │     │  │     >
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     >
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     >
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     >
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     >
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     >
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     │
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     │
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     │
│    │▒▒│     │▒▒│      │▒▒│               │▒▒│     │  │     │
│    ├──┤     ├──┤      ├──┤     ┌──┐      ├──┤     ├──┤     │
│    │OO│     │OO│      │OO│     │MM│      │OO│     │MM│     │
│    └──┘     └──┘      └──┘     └──┘      └──┘     └──┘     │
│   74<>74     74      74<>74             74<>74    0<>0     │
│ < Master >Master M  Headphon Headphon    PCM      Line     │
└────────────────────────────────────────────────────────────┘

At the top, note the status information. Make sure that 'Card' says something sensible (usually Intel something, but whatever makes sense for that machine). Also make sure you're adjusting the Playback or Capture (record) views as appropriate, to avoid confusion: you can choose between these with Tab.

You can move between alsamixer lines with the arrow keys, as you'd expect: your current selected line is <bracketed> , and its full name is shown in the "Item" status line at the top. Note the ">" symbols on the right border, indicating that further volume lines are hidden off-screen. You can adjust volume on these lines with up and down, and toggle their mute status with 'M' key.

Note, on a typical DICE machine, the multiple 'Master' volume lines, the 'OO' (On) and 'MM' (Mute) states, and the lines without a volume bar (notably the second of the 'Headphon' entries).

Typically important volume lines:

  • Master: all output (apart from Master Mono) will depend on this, headphone or otherwise. Shouldn't typically be muted.
  • Master Mono: this will control the built-in speaker on most hardware. Shouldn't typically need to be muted unless external speakers are plugged in, or the headphone jack sense isn't doing its job.
  • Headphone: often this controls only the headphone socket on the front of the PC, not at the back. Generally should not be muted.
  • Headphone Jack Sense: when enabled (OO) this line should disable other sources of sound when headphones are plugged into the headphone socket.
  • PCM: 'regular' audio (sound files, videos, etc.) is processed through this line. This should never be muted (unless you don't want to head audio). Unless things are very quiet you should also take care to keep this at a gain level of no more than 0dB (on this line, alsamixer represents amplification in red, so about 3/4 volume represents the highest unamplified level).
  • External Amplifier: enabled (OO) if you are using external, powered speakers (not headphones); disabled (MM) otherwise.

Final note: Quit using Esc - for some reason this is not instantaneous but be patient! Don't impatiently stab at q, as I tend to do: q/z adjust the left-channel volume up and down by one unit, and will leave you feeling a little unbalanced!

Troubleshooting

No sound

Check that 'Master', 'Master Mono', and 'PCM' are all unmuted and above minimum volume.

Distorted sound

Check that the PCM and any similar lines do not have gain above 0dB.

Sound comes out of the front speaker when it shouldn't

Check that 'Headphone Jack Sense' is ON (showing OO): toggle with the 'M' key. Failing that you can mute the internal speaker by muting (with 'M') the 'Master Mono' line.

Error starting alsamixer: ...

For example:

$ alsamixer
alsamixer: function snd_ctl_open failed for default: No such device

This suggests that there's no sound card available. You can try opening an alternative device using

 $ alsamixer -c#

where # is a number (0 is the default as confirmed by the alsacard command).

Mixer doesn't control any volume levels

You're probably using an external / alternative sound card. Try changing the card, as in the above question. You can also select an ALSA device by name, e.g.

$ alsamixer -c usb

Also check that you've not slipped into 'Capture' or 'All' views: press Tab and make sure you're on Playback so that you can only adjust playback lines.

Last reviewed: 
10/05/2017

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