Linux: alsa sound commands, howto

Pulse Audio (linux command pavucontrol) is definitely one of the best ways to handle sound settings under linux. Once in a while it might however be good to use the alsa sound commands directly since they offer some extra settings dependent on the sound cards capabilities.

Listing alsa devices and sound cards

One would expect that alsamixer is able to provide control of all sound card features and that is the case but you need the card number or device and alsamixer is not capable to list the available choices. You need to use aplay or arecord to get that information:
List card numbers: aplay -l or arecord -l List devices (things within a card): play -L or arecord -L

Examples:
guido@ecopad ~ $ arecord -l **** List of CAPTURE Hardware Devices **** card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 1: Device [USB Audio Device], device 0: USB Audio [USB Audio] Subdevices: 1/1 Subdevice #0: subdevice #0 guido@ecopad ~ $ arecord -L default:CARD=Intel HDA Intel, CONEXANT Analog Default Audio Device front:CARD=Intel,DEV=0 HDA Intel, CONEXANT Analog Front speakers surround40:CARD=Intel,DEV=0 HDA Intel, CONEXANT Analog 4.0 Surround output to Front and Rear speakers surround41:CARD=Intel,DEV=0 HDA Intel, CONEXANT Analog 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=Intel,DEV=0 HDA Intel, CONEXANT Analog 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=Intel,DEV=0 HDA Intel, CONEXANT Analog 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=Intel,DEV=0 HDA Intel, CONEXANT Analog 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers null Discard all samples (playback) or generate zero samples (capture) default:CARD=Device USB Audio Device, USB Audio Default Audio Device front:CARD=Device,DEV=0 USB Audio Device, USB Audio Front speakers surround40:CARD=Device,DEV=0 USB Audio Device, USB Audio 4.0 Surround output to Front and Rear speakers surround41:CARD=Device,DEV=0 USB Audio Device, USB Audio 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=Device,DEV=0 USB Audio Device, USB Audio 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=Device,DEV=0 USB Audio Device, USB Audio 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=Device,DEV=0 USB Audio Device, USB Audio 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=Device,DEV=0 USB Audio Device, USB Audio IEC958 (S/PDIF) Digital Audio Output

Using alsamixer

In most cases it's the easiest to start alsamixer for a specific card. To know which card is which you use the above commands.
Start alsamixer for card 1: alsamixer -V all -c 1 You quit alsamixer with Esc. The first card (usally the on-board audio card) is card 0.

To go from control to you use the arrow left and right keys. You change the volume with the arrow up/down keys and you can mute or un-mute a controller with the m-key.

F1 displays a help and you get out of help by pressing Enter.

© Guido Socher,