Alsamixer

Some not so obvious things that you might miss reading the manual.

Audio devices

Audio devices are in '/dev/snd/';

0 drwxr-xr-x  3 root root      200 2024-02-14 15:44 .
0 drwxr-xr-x 16 root root     3400 2024-02-16 18:40 ..
0 drwxr-xr-x  2 root root       60 2024-02-14 15:44 by-path
0 crw-rw----  1 root audio 116,  6 2024-02-14 15:44 controlC0
0 crw-rw----  1 root audio 116,  5 2024-02-14 15:44 hwC0D0
0 crw-rw----  1 root audio 116,  3 2024-03-20 19:24 pcmC0D0c
0 crw-rw----  1 root audio 116,  2 2024-03-20 19:33 pcmC0D0p
0 crw-rw----  1 root audio 116,  4 2024-03-20 19:09 pcmC0D2c
0 crw-rw----  1 root audio 116,  1 2024-02-14 15:44 seq
0 crw-rw----  1 root audio 116, 33 2024-02-14 15:44 timer

Device file names ending in 'c' are capture devices. Device file names ending in 'p' are playback devices. You need both for a VoIP client.

Show more

Show both inputs and outputs: F5. The default behaviour is to show inputs only. You need to set both for VoIP.
Select sound card: F6. For VoIP, you need the sound card that is connected to your head set.

Input or Output On / Off

Toggle on / off with 'm' (Mute).
Bottom of slider: Left is Off ('MM'), right is On ('OO');

   ┃  ┃     ┃  ┃   
   ┣━━┫     ┣━━┫   
   ┃MM┃     ┃OO┃
   ┗━━┛     ┗━━┛   
                  
  65<>65   65<>65 
 Front Mi Front Mi

Sometimes there is no switch. And sometimes there is no slider;

   ┏━━┓     ┏━━┓   
   ┃MM┃     ┃OO┃   
   ┗━━┛     ┗━━┛   
                  
                  
  S/PDIF   S/PDIF  

Capture On / Off

Toggle on / off with space;
Bottom of slider: Left is Off ('-------'), right is On ('CAPTURE');

   ┃  ┃     ┃  ┃   
   ┗━━┛     ┗━━┛  
                 
           L    R
 -------  CAPTURE 
  42<>42   42<>42 
 Capture  Capture 

Note: You need this if you want to record sound or use it for VoIP! If your microphone doesn't work you probably got this wrong.

Input Source

This is front mic, rear mic or line.
If you want to use a soft phone with a head set, set this to 'Front mic'.

Input Values

Some input values that work for me.
Note: Things may get weird if these are way off!

Auto-Mute

This will switch off speakers when you plug-in headphones.
If you want to use both headphones and speakers, set this to 'disabled'.

Loopback

With this enabled you can hear yourself. Nice for tests. Otherwise set to 'disabled'.