Audio Splitting in Linux

Pre-Requisites

You’ll need to have both pulseaudio and pavucontrol installed on your system

Install For Ubuntu

sudo apt-get pulseaudio pavucontrol

Install For Arch

pacman -S pulseaudio pavucontrol

# OR

yay -S pulseaudio pavucontrol

Setting up a new audio sink

Make a new directory called .pulse in your home directory, this is the default pulseaudio config folder. Note that depending on your OS, the default pulseaudio directory could be in a different path or different folder name. Check your man pages with man pulseaudio.

 mkdir ~/.pulse

Copy the default pulseaudio config, default.pa, into the new folder.

cp /etc/pulse/default.pa ~/.pulse/

Make sure the new file is in your directory

ls -la ~/.pulse

Next, you need to find all of your current audio sinks:

pacmd list-sinks | grep -e 'index:' -e 'name:'

This will show all of your audio output devices. Your output should look something like this:

    index: 0
 name: <alsa_output.pci-0000_01_00.1.hdmi-stereo>
  * index: 1
 name: <alsa_output.usb-Razer_Razer_Kraken_7.1_V2_00000000-00.analog-stereo>
    index: 2
 name: <alsa_output.pci-0000_00_1f.3.analog-stereo>

The * symbol shows your currently active audio output.

Copy the audio output you want to direct audio towards. For me, I want to be able to send all audio source I’m monitoring to my headset. So I would copy alsa_output.usb-Razer_Razer_Kraken_7.1_V2_00000000-00.analog-stereo. Paste this in a empty text document. You’ll need this info later.

Next, you’ll want to make a dummy audio sink. To do this, open up ~/.pulse/default.pa in a text editor. Go all the way to the bottom of the document and use this template to define your new audio sink.

Here is a template that you can use:

load-module module-null-sink sink_name=channelname
update-sink-proplist channelname device.description="channelname Audio"
update-source-proplist channelname.monitor device.description='Monitor of channelname Audio'
load-module module-loopback source=channelname.monitor sink=outputdevicename latency_msec=1

Replace channelname with your audio sink name, then replace outputdevicename with the audio output device we copied earlier.

Example

I used this to better control which audio source I want to be streamed on twitch through OBS but still be able to monitor and hear everything. Here’s what my default.pa looks like

load-module module-null-sink sink_name=twitchaudio
update-sink-proplist twitchaudio device.description='Twitch Streaming Audio'
update-source-proplist twitchaudio.monitor device.description='Monitor of Twitch Audio'
load-module module-loopback source=twitchaudio.monitor sink=alsa_output.usb-Razer_Razer_Kraken_7.1_V2_00000000-00.analog-stereo latency_msec=1

Restart Pulseaudio And All Of Your Apps

After you’re done making custom audio sinks, make sure to restart pulseaudio using this command:

pulseaudio --kill

This should automatically restart pulseaudio, but if it doesn’t, you can manually start it with:

pulseaudio --start

After restarting pulseaudio, you’ll find that there’s no audio. You’ll need to restart all your apps that streams audio to your speakers.

Pulseaudio Volume Control App (pavucontrol)

From here launch pavucontrol and you’ll be able to see your new audio sink in the recording, playback, and output devices tabs. ` This app will let you control where you want all of your audio sources to be directed to.

Misc

For more info, check out the arch wiki page: wiki.archlinux.org