The top-left corner of alsamixer is the are to show some basic information: the card name, the mixer chip name, the current view mode and the currently selected mixer item. When the mixer item is switched off, [Off] is displayed in its name.
Volume bars are located below the basic information area. You can scroll left/right when all controls can't be put in a single screen. The name of each control is shown in the bottom below the volume bars. The currently selected item is drawn in red and/of emphasized.
Each mixer control with volume capability shows a box and the current volume filled in that box. The volume percentages are displayed below the volume bar for left and right channels. For a mono control, only one value is shown there.
When a mixer control is turned off, M (mute) appears below the volume bar. When it's turned on, O in green appears instead. You can toggle the switch via m key.
When a mixer control has capture capability, the capture flag appears below the volume bar, too. When the capture is turned off, ------- is shown. CAPTURE in red appears when the capture switch is turned on. In addition, L and R letters appear in left and right side to indicate that left and the right channels are turned on.
Some controls have the enumeration list, and don't show boxes but only texts which indicate the currently active item. You can change the item via up/down keys.
The default view mode is the playback view. You can change it via -V option.
Each view mode can be switched via keyboard commands, too. See the next section.
The Left and right arrow keys are used to select the channel (or device, depending on your preferred terminology). You can also use n ("next") and p ("previous").
The Up and Down Arrows control the volume for the
currently selected device. You can also use + or - for the
same purpose. Both the left and right signals are affected. For
independent left and right control, see below.
The B or = key adjusts the balance of volumes on left and right channels.
M toggles muting for the current channel (both left and right). If the hardware supports it, you can mute left and right independently by using , (or <) and . (or >) respectively.
SPACE enables recording for the current channel. If any other channels have recording enabled, they will have their recording function disabled first. This only works for valid input channels, of course.
L re-draws the screen.
F3, F4 and F5 keys are used to switch to playback, capture and all view mode, respectively. TAB key toggles the current view mode circularly.
PageUp increases volume by 5.
PageDown decreases volume by 5.
End sets volume to 0.
You can also control left & right levels for the current channel independently, as follows:
[Q | W | E ] -- turn UP [ left | both | right ]
[Z | X | C ] -- turn DOWN [ left | both | right ]
If the currently selected mixer channel is not a stereo channel, then all UP keys will work like W, and all DOWN keys will work like X.
The number keys from 0 to 9 are to change the absolute volume quickly. They correspond to 0 to 90% volume.
You can select another sound card by pressing the F6 or S keys. This will show a list of available sound cards to choose from, and an entry to enter the mixer device name by hand.
Quit the program with ALT Q, or by hitting ESC. Please note that you might need to hit ESC twice on some terminals since it's regarded as a prefix key.
Only for controls without dB information, a linear mapping of the hardware volume register values is used (this is the same algorithm as used in the old alsamixer).
This manual page was provided by Paul Winkler <firstname.lastname@example.org>.