Mic Gain

Products Support DragonBoard410c
#1

hi
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).
thanks…

#2

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

thanks,
srini

#3

thank you.

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

#4

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

–srini

#5

Hi srini,

How could I adjust Primary Microphone control by amixer command?

Thanks.

#6

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.
thanks,
srini

#7

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?

Thanks.