First: List the audio output devices using:
pactl list short sources
Example of the output:
0 alsa_output.usb-Dell_Dell_AC511_USB_SoundBar-00.analog-stereo.monitor module-alsa-card.c s16le 2ch 44100Hz SUSPENDED
1 alsa_input.usb-Dell_Dell_AC511_USB_SoundBar-00.analog-stereo module-alsa-card.c s16le 2ch 44100Hz SUSPENDED
2 alsa_output.pci-0000_00_1b.0.analog-stereo.monitor module-alsa-card.c s16le 2ch 44100Hz IDLE
3 alsa_input.pci-0000_00_1b.0.analog-stereo module-alsa-card.c s16le 2ch 44100Hz SUSPENDED
4 alsa_input.usb-046d_HD_Pro_Webcam_C920_627B04DF-02.analog-stereo module-alsa-card.c s16le 2ch 32000Hz SUSPENDED
Now, to make this work at every restart, follow this :
sudo -H gedit /etc/pulse/default.pa
Example of the edit:
### Make some devices default ### sink(for output) / source(for input)
#set-default-sink output
#set-default-source input
set-default-sink alsa_output.pci-0000_00_1b.0.analog-stereo.monitor
#set-default-source input
----
Sources:
AskUbuntu
Rastating.
