freebsd man page for mixer

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

NAME
     mixer -- set/display soundcard mixer values

SYNOPSIS
     mixer [-f device] [-s | -S] [dev [[+|-]lvol[:[+|-]rvol]]] ...
     mixer [-f device] [-s | -S] recsrc ...
     mixer [-f device] [-s | -S] {^|+|-|=}rec rdev ...

DESCRIPTION
     The mixer utility is used to set and display soundcard mixer device levels.  It may also be used to start and stop recording from the sound-
     card.  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 the current settings for all supported devices, followed by information about the current recording
     input devices.  If the dev argument is specified, mixer displays only the value for that dev.

     To modify the mixer value dev, the optional left and right channel settings of lvol[:rvol] may be specified.  The lvol and rvol arguments may
     be from 0 - 100.  Omitting dev and including only the channel settings will change the main volume level.

     If the left or right channel settings are prefixed with + or -, the value following will be used as a relative adjustment, modifying the cur-
     rent settings by the amount specified.

     If the -s flag is used, the current mixer values will be displayed in a format suitable for use as the command-line arguments to a future
     invocation of mixer (as above).

     The -S flag provides the above output without mixing field separators.

     To change the recording device you use one of:

	   ^rec  toggles rdev of possible recording devices

	   +rec  adds rdev to possible recording devices

	   -rec  removes rdev from possible recording devices

	   =rec  sets the recording device to rdev

     The above commands work on an internal mask.  After all the options have been parsed, it will set then read the mask from the sound card.
     This will let you see EXACTLY what the soundcard is using for the recording device(s).

     The option recsrc will display the current recording devices.

     The option -f device will open device as the mixer device.

FILES
     /dev/mixer  the default mixer device

SEE ALSO
     cdcontrol(1), sound(4)

HISTORY
     The mixer utility first appeared in FreeBSD 2.0.5.

AUTHORS
     Original source by Craig Metz <cmetz@thor.tjhsst.edu> and Hannu Savolainen.  Mostly rewritten by John-Mark Gurney <jmg@FreeBSD.org>.  This
     manual page was written by Mike Pritchard <mpp@FreeBSD.org>.

BSD
								   June 2, 2014 							       BSD