Mic Gain


Does anyone know how to adjust the microphone gain?
OS: Linux
which command can set mic gain?
in PM8916 Spec Microphone can be adjust to 24dB(maximum gain).


You can use,
amixer cset iface=MIXER,name='ADC2 Volume’
mixer control to adjust the mic gain for headset mic and secondary mic.



thank you.

but i need to know how to send command to adjust it. not use mixer control.


What do mean by sending command?

amixer is the command to set the the volume.

You can adjust Analog Gain control from 0 dB to +24 dB in 6 dB steps using the mixer control I mentioned in last comment.

Or you can set 100% volume using command
amixer set ‘ADC2’ 100%

for more details source code is available at https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/sound/soc/codecs/msm8916-wcd-analog.c?id=refs/tags/v4.10-rc3#n262



Hi srini,

How could I adjust Primary Microphone control by amixer command?



Hi Miles,
Primary mic goes via ADC1, so “amixer set ‘ADC1’ 100%” command should do the job.
TBH, I did not get chance to test primary mic on my setup.


Hi srini,

I check the ADC1 100% [dB gain:48.00]
But the GUI tool “PulseAudio Volume Control” only adjust Maximum 11dB.
It is the same situation if I use ADC2.
Why “PulseAudio Volume Control” cannot adjust up to 48dB?