Default sound volume for all ALSA devices

alsaaudioconfiguration

I woud like to set up the default sound volume once for all, for all ALSA devices that will be connected ever.

Of course, I could do amixer ... or even alsamixer to modify the volume of currently available soundcards.
But I really want to modify the default volume even for future soundcards that will be added later.

In which config file should I set this default sound volume?

I've seen /var/lib/alsa/asound.state but the content is specific to currently connected soundcards.
What I want is a solution that will apply to any soundcard that will be connected.

Context : why do I want this? I'm providing a ready-to-use Debian image for my project SamplerBox. User #1 might use the computer's built-in-soundcard, User #2 might have a USB DAC, User #3 might have another soundcard…
I would like to provide a default -3dB volume that will work for any ALSA soundcard people could have…

Note: I reinstalled a fresh new system and it seems that, by default, the volume is -20dB for all devices :

enter image description here

Best Answer

There are some generic and driver-specific config files in /usr/share/alsa/init/, where you can specify settings like ENV{ppercent}:="75%" and ENV{pvolume}:="-20dB" (pvolume = playback volume, cvolume = capture volume, etc.). /usr/share/alsa/init/default should already contain those settings, so you can use it as an example.

You can force ALSA to re-initialize all devices with alsactl init and can also override the default configuration files for that with alsactl -i /usr/share/alsa/init/foo init.

For some reason, ALSA seems to ignore the ppercent and pvolume settings on my system, but from your comments it seems like they worked for you. If anyone can enlighten me on why the configuration might be ignored, I'd be glad to amend this answer.

Related Solutions

ALSA: send audio to two audio devices

Here's one way to do it from ~/.asoundrc ; example shows an on-board and soundblaster live card united under the default PCM.

# duplicate audio to both devices
pcm.!default plug:both

ctl.!default {
  type hw
  card SB
}

pcm.both {
  type route;
  slave.pcm {
      type multi;
      slaves.a.pcm "sblive";
      slaves.b.pcm "onboard";
      slaves.a.channels 2;
      slaves.b.channels 4;
      bindings.0.slave a;
      bindings.0.channel 0;
      bindings.1.slave a;
      bindings.1.channel 1;

      bindings.2.slave b;
      bindings.2.channel 0;
      bindings.3.slave b;
      bindings.3.channel 1;
      bindings.4.slave b;
      bindings.4.channel 2;
      bindings.5.slave b;
      bindings.5.channel 3;
  }

  ttable.0.0 1;
  ttable.1.1 1;

  ttable.0.2 1; # front left
  ttable.1.3 1; # front right
  ttable.0.4 1; # copy front left to rear left
  ttable.1.5 1; # copy front right to rear right
}

ctl.both {
  type hw;
  card Live;
}

pcm.onboard {
   type dmix
   ipc_key 1024
   slave {
       pcm "hw:0,1"
       period_time 0
       period_size 2048
       buffer_size 65536
       buffer_time 0
       periods 128
       rate 48000
       channels 4
    }
    bindings {
       0 0
       1 1
       2 2
       3 3
    }
}

pcm.sblive {
   type dmix
   ipc_key 2048
   slave {
       pcm "hw:1,0"
       period_time 0
       period_size 2048
       buffer_size 65536
       buffer_time 0
       periods 128
       rate 48000
       channels 2
    }
    bindings {
       0 0
       1 1
    }
}

ctl.onboard {
   type hw
   card "SB"
}

ctl.sblive {
   type hw
   card "Live"
}

(Source)

How to get the unsupported sound card to work with ALSA

Partial answer:

The info you provided has a section about the codec, and that tells you that this particular codec is not recognized:

Codec: Realtek Generic
...
Vendor Id: 0x10ec0287
Subsystem Id: 0x17aa3813
Revision Id: 0x100002

On my system, the first line says

Codec: Realtek ALC892

The code for the patches that deal with the various codecs is in /sound/pci/hda/patch_realtek.c, at least for the relatively old kernel I use at the moment.

So to get your sound working, you need to debug what's going wrong with the codec, then write a patch, and include it in the code, so everyone else with that hardware can have it working.

The codec information can be dumped with cat /proc/asound/card*/codec\#*. Read up on how an Intel HDA Codec works, and debug it.

I recommend disabling Pulseaudio. hda-verb from the alsa-tools package (at least that's how it is called on Debian) may also help.

You can google datasheets for older codecs to understand how they work.

Best Answer

Related Solutions

ALSA: send audio to two audio devices

How to get the unsupported sound card to work with ALSA

Related Question