Set up default audio device on Ubuntu 20.04 LTS

readme.md

Problem

I have a notebook connected to a port replicator. I want to use the build-in speakers and microfone and not the external ones. If I boot my notebook in my port replicator Ubuntu changes the devices to external.

Solution

1. Find your internal speaker

pactl list short sinks

0	alsa_output.usb-Generic_USB_Audio_201405280001-00.analog-stereo	module-alsa-card.c	s16le 2ch 44100Hz	SUSPENDED
1	alsa_output.pci-0000_00_1f.3.analog-stereo	module-alsa-card.c	s16le 2ch 44100Hz	SUSPENDED

2. Set your internal speaker as default pactl set-default-sink <DEVICE> e.g. pactl set-default-sink alsa_output.pci-0000_00_1f.3.analog-stereo

3. Add to "Startup Applications" ("Startprogramme" in German)

• Open the application "Startup Applications" (Should be preinstalled on Ubuntu)
• Click on "Add"
• Give your startup item a name
• Copy your command from above into the command field.
• Click on "Save".

4. Find your internal microfone

pactl list short sources

0	alsa_output.usb-Generic_USB_Audio_201405280001-00.analog-stereo.monitormodule-alsa-card.c	s16le 2ch 44100Hz	SUSPENDED
1	alsa_input.usb-Generic_USB_Audio_201405280001-00.iec958-stereo	module-alsa-card.c	s16le 2ch 44100Hz	RUNNING
2	alsa_output.pci-0000_00_1f.3.analog-stereo.monitor	module-alsa-card.c	s16le 2ch 48000Hz	SUSPENDED
3	alsa_input.pci-0000_00_1f.3.analog-stereo	module-alsa-card.c	s16le 2ch 44100Hz	SUSPENDED

5. Set your internal speaker as default pactl set-default-source <DEVICE> e.g. pactl set-default-source alsa_input.pci-0000_00_1f.3.analog-stereo

6. Repeat step 3.

Edit etc/pulse/default.pa is the better solution. However, the comments above seem not working in my case Ubuntu 20.04.4 (desktop with sound card + web cam + USB headset) because:

• The numerical ID of sinks & sources change at each reboot. So hard-coding an ID is inaccurate
• set-default-... alone is not enough, I end up with two devices enabled. The one pre-selected by PulseAudio (which I don't know based on which criteria) and the one I set by set-default-...

The working solution for me is:

1. Get the current default devices selected by PulseAudio (those having RUNNING as status)

echo '\nSINKS (output)' && pactl list short sinks && echo '\nSOURCES (input)' && pactl list short sources

SINKS (output)
0       alsa_output.pci-0000_04_00.1.hdmi-stereo        module-alsa-card.c      s16le 2ch 48000Hz       SUSPENDED
1       alsa_output.usb-Logitech_Logitech_B530_USB_Headset-00.analog-stereo     module-alsa-card.c      s16le 2ch 48000Hz       RUNNING
2       alsa_output.pci-0000_00_1b.0.analog-stereo      module-alsa-card.c      s16le 2ch 48000Hz       SUSPENDED

SOURCES (input)
0       alsa_output.pci-0000_04_00.1.hdmi-stereo.monitor        module-alsa-card.c      s16le 2ch 48000Hz       SUSPENDED
1       alsa_output.usb-Logitech_Logitech_B530_USB_Headset-00.analog-stereo.monitor     module-alsa-card.c      s16le 2ch 48000Hz       SUSPENDED
2       alsa_input.usb-Logitech_Logitech_B530_USB_Headset-00.mono-fallback      module-alsa-card.c      s16le 1ch 48000Hz       SUSPENDED
3       alsa_input.usb-HK_5M_EKACOM-K20E_200901010001-02.analog-stereo  module-alsa-card.c      s16le 2ch 48000Hz       RUNNING
4       alsa_output.pci-0000_00_1b.0.analog-stereo.monitor      module-alsa-card.c      s16le 2ch 48000Hz       IDLE

2. Edit /etc/pulse/default.pa explicitly suspend the devices selected by PulseAudio and set-default the one you want

# CHANGE
#set-default-sink output
#set-default-source input

# TO
suspend-sink alsa_output.usb-Logitech_Logitech_B530_USB_Headset-00.analog-stereo true
set-default-sink alsa_output.pci-0000_00_1b.0.analog-stereo
suspend-source alsa_input.usb-HK_5M_EKACOM-K20E_200901010001-02.analog-stereo true
set-default-source alsa_input.usb-Logitech_Logitech_B530_USB_Headset-00.mono-fallback

3. Reboot. Maybe pulseaudio --kill && pulseaudio --start would be enough but in my case I tested the real use-case with a reboot.

Reference: Ubuntu manual - pactl

(Ubuntu 22.04 LTS) doing the same when logging into Ubuntu Desktop did it for me:

vi ~/.config/autostart/my_script.desktop

[Desktop Entry]
Type=Application
Name=My Script
Exec=/home/<path-to-your-script>/install-sound.sh
Icon=system-run
X-GNOME-Autostart-enabled=true

vi /home/<path-to-your-script>/install-sound.sh

#!/bin/bash

# get list of available available audio output devices (sinks)
# pactl list short sinks
# set default output device to HDMI/DisplayPort LG monitor

pactl set-default-sink alsa_output.pci-0000_01_00.1.hdmi-stereo

# get list of available available audio input devices (sources):
#pactl list short sources
# set default audio input to USB BRIO web camera

pactl set-default-source alsa_input.usb-046d_Logitech_BRIO_301280B8-02.analog-stereo

+1

thank you very much worked perfectly

Thank you! This fixed my problem!

How do I find out the location of install-sound.sh file??

Thank you so much!! 🔊 🎶

I see no difference in my pactl list short sinks output when plugging out or plugging in my headphones:

Just this list of 4 sinks, all in a suspended state.
Is there a way to find the device using the human friendly name that's in settings instead?

Gnome really needs something like this:

Or just remember the state of the previously selected audio device on reboot.

How would one handle if there are multiple defaults?

For example when my bt headphones is disconnected i'd like to default to the speakers but when i connect my headphones it should default to the headphones.

Or is this entirely beyond the scope of what is attempted here?

edit: answered my own question with some searching, this is a combination of the above and an udev rule.
see https://askubuntu.com/questions/686144/run-a-shell-command-after-a-bluetooth-input-device-is-detected for the info i used

edit2: you need to add the --server= flag to the pactl command for udev to set your sink or source, you can get the server with pactl info use the server string, you need this because root will run your script which has no known pulseaudio session.
Now my bt headset and default speakers switch seamlessly (both ways) ^^

Thank you the solution is still working, I thought that it was enough setting up the line output as it was picking up the Microphone default correctly, but no, it did not work until I also setup the default microphone.

Works great on Ubuntu 20.04, thank you!

It's still working on Ubuntu 24.04.1 LTS, thanks for the trick 👍

Working on 24.04.01 LTS, thank you so much for this! [U+1F601]