Control jack output volume

Products & Technology ReSpeaker
#1

Device: Respeaker Mic Array v2

Raspberry Pi with Raspbian Stretch



I’m trying to figure out how I can change the output volume for the jack output on the Respeaker Mic Array.



Since the output channel uses S24_LE I don’t think I can use the normal alsamixer controls? Or is my .asoundrc wrong?

[code]
pcm.!default {
type plug
slave {
pcm “hw:1,0”
}
}

ctl.!default {
type hw
card 1
}
[/code]

Also, I tried to use the pixel_ring python code and use “pixel_ring.set_volume(10)” (and other numbers) to change the output volume. But maybe I misunderstand what that line does. Is it supposed to change the jack output volume? Because it doesn’t seem to do anything…

#2

Hi there,



We can use alsa+softvol or pulseaudio to control the mic array v2.0 volume. thanks.



Bill

#3

Hi Bill,



That is good to hear! However, in my case this doesn’t seem to work. Is my .asoundrc in my first post wrong? Or am I doing something else wrong?

#4

Hi

After a couple of hours trying to figure out how alsa + softvol works from various sources, here is my working /etc/asound.conf file , in the hope it may help newbies in alsa/sound conf like me.



This card (usb ReSpeaker 4 Mic Array) doesn’t allow sound volume hardware configuration : you need to create a “softvol” “virtual” device that will allow you to modify the sound volume before sending it to the card PCM device. Check by launching “alsamixer”, F3 to change card/device -> warning message.

[code]
pcm.bcm2835 {
type hw
card ALSA
}
pcm.ArrayUAC10 {
type plug
slave.pcm “hw:1,0”
}

pcm.softvol {
type softvol
slave {
pcm “ArrayUAC10”
}
control {
name “Master”
card 0
}
}

pcm.!default {
type asym
playback.pcm “plug:softvol”
capture.pcm “ArrayUAC10”
}
[/code]

My configuration : Pi3 B+ with ReSpeaker 4 Mic Array v2 (UAC1.0) plugged via USB cable

This conf defaults to :

  • output via ReSpeaker Jack (to benefits from Noise Cancelation etc…)
  • Input (capture) from Array Mics



    No reboot needed but…

    Check with ‘alsamixer’ or ‘amixer’ : a new “Master” mixer sound control is now available :


amixer

Simple mixer control ‘Master’,0

Capabilities: volume

Playback channels: Front Left - Front Right

Capture channels: Front Left - Front Right

Limits: 0 - 255

Front Left: 237 [93%]

Front Right: 237 [93%]

Simple mixer control ‘PCM’,0

Capabilities: pvolume pvolume-joined pswitch pswitch-joined

Playback channels: Mono

Limits: Playback -10239 - 400

Mono: Playback 311 [99%] [3.11dB] [on]



Test with : aplay -f cd test.wav

adjust sound via command line : amixer sset ‘Master’ 70%



Source who helped :

<LINK_TEXT text=“https://alsa.opensrc.org/How_to_use_sof … ter_volume”>https://alsa.opensrc.org/How_to_use_softvol_to_control_the_master_volume</LINK_TEXT>



My usecase : https://snips.ai/ (alexa/GHome (real/serious/capable) alternative voice assistant not using any Cloud, speech recognition is 100% made on the Pi : PRIVACY by design)

#5

This Github issue addresses the question of having simpler volume control for the headphone jack.