MIXER(8)                FreeBSD System Manager's Manual               MIXER(8)

NAME

     mixer - manipulate soundcard mixer controls

SYNOPSIS

     mixer [-f device] [-d pcmX | X] [-os] [dev[.control[=value]]] ...
     mixer [-os] -a
     mixer -h

DESCRIPTION

     The mixer utility is used to set and display soundcard mixer device
     controls.

     The options are as follows:

     -a           Print the values for all mixer devices available in the
                  system (see FILES).

     -d pcmX | X  Change the default audio card to pcmX, where X is the
                  device's unit number (e.g for pcm0, the unit number is 0).
                  See EXAMPLES on how to list all available audio devices in
                  the system.

     -f device    Open device as the mixer device (see FILES).

     -h           Print a help message.

     -o           Print mixer values in a format suitable for use inside
                  scripts.  The mixer's header (name, audio card name, ...)
                  will not be printed.

     -s           Print only the recording source(s) of the mixer device.

     The list of mixer devices that may be modified are:

           vol, bass, treble, synth, pcm, speaker, line, mic, cd, mix, pcm2,
           rec, igain, ogain, line1, line2, line3, dig1, dig2, dig3, phin,
           phout, video, radio, and monitor.

     Not all mixer devices are available.

     Without any arguments, mixer displays all information for each one of the
     mixer's supported devices to stdout.  If the dev argument is specified,
     mixer displays only the values for dev.  More than one device may be
     specified.

     Commands use the following format:

           Name                        Action
           dev                         Display all controls
           dev.control                 Display only the specified control
           dev.control=value           Set control value

     The available controls are as follows (replace dev with one of the
     available devices):

           Name                        Value
           dev.volume                  vol|[+|-]lvol[%][:[+|-]rvol[%]]
           dev.mute                    off|on|toggle
           dev.recsrc                  toggle|add|remove|set

     The dev.volume control modifies a device's volume.  The optional lvol
     and/or rvol values have to be specified.  The values should typically be
     decimal numbers between 0 and 1 with at most 2 digits after the decimal
     point.  A trailing percent sign indicates that the value should be
     treated as a percentage of 1.0, rather than an absolute value.  Thus, 70%
     means the same as 0.7.  If the left or right volume values are prefixed
     with + or -, the value following will be used as a relative adjustment,
     modifying the current settings by the amount specified.  Note that
     relative percentages are still relative to 1.0, not to the current value.
     If the volume is currently 0.40 and an adjustment of +20% is specified,
     then the final volume will be set to 0.60.

     Volume can also be set using the shorthand dev=value.  This syntax does
     not apply to other controls.

     The dev.mute control (un)mutes a device.  The following values are
     available:

           off         unmutes dev

           on          mutes dev

           toggle      toggles the mute of dev

     The dev.recsrc control modifies the recording sources of a mixer.  mixer
     marks devices which can be used as a recording source with rec.
     Recording sources are marked with src.  To modify the recording source
     you can use one of the following modifiers on a rec device:

           toggle      toggles dev of possible recording devices

           add         adds dev to possible recording devices

           remove      removes dev from possible recording devices

           set         makes dev the only recording device.

FILES

     /dev/mixerX  The mixer device, where X is the unit number of that device,
                  /dev/dsp* devices and /dev/mixer* devices have a 1:1
                  relationship, which means that, for instance, /dev/mixer0 is
                  the mixer device for /dev/dsp0.
     /dev/mixer   Alias to the default device's mixer device.  mixer opens
                  this when the -f device option is not specified.

EXAMPLES

     List all available audio devices in the system:

           $ mixer -a | grep ^pcm

     Increase the vol device's volume by 5%:

           $ mixer vol=+5%

     Change the volume for the vol device of the /dev/mixer0 mixer device to
     0.65:

           $ mixer -f /dev/mixer0 vol.volume=0.65

     Increase the mic device's left volume by 0.10 and decrease the right
     volume by 0.05:

           $ mixer mic.volume=+0.10:-0.05

     Toggle the mute for vol:

           $ mixer vol.mute=toggle

     Add mic and remove line from the recording devices:

           $ mixer mic.recsrc=add line.recsrc=remove

     Dump /dev/mixer0 information to a file and retrieve back later:

           $ mixer -f /dev/mixer0 -o > info
           ...
           $ mixer -f /dev/mixer0 `cat info`

SEE ALSO

     mixer(3), sound(4), sysctl(8)

HISTORY

     The mixer utility first appeared in FreeBSD 2.0.5 and was rewritten
     completely in FreeBSD 14.0.

AUTHORS

     Christos Margiolis <christos@FreeBSD.org>

FreeBSD 15.1-STABLE-HBSD         April 4, 2026                        MIXER(8)