A personal repository with notes about installing, configuring, and using Linux applications. This is all part of the learning and documenting process!
tags: #audio
This is a guide on how to set up JACK, a powerful audio driver for Linux used for media, podcasting, streaming and music production, but can also be for personal use for sound device management. Due to lack of documentation (except perhaps for the Arch Wiki), JACK is sometimes difficult to implement. After scrounging around, I eventually managed to get it working. I’m hoping these notes will help anyone who is having difficulty setting it up.
These instructions assume you’re using PulseAudio by default, as we’ll be routing JACK through it. I am also writing these instructions while using Pop_OS 22.04. However, I’ve also managed to do this through Linux Mint, so am assuming this will working on most, if not all debian-based distros.
You can also configure JACK without Cadence / Claudia / Catia and simply use the light-weight Qjackctl. At the time of writing, I opted to step away from the KXstudio tools as they’re using LADISH, which is now deprecated.
Let’s install PAVUcontrol as it will allow us to direct any application to any audio device. Particularly useful to route Audio Cables to the right place. Unfortunately, PulseAudio doesn’t allow us to do this by default.
sudo apt install pavucontrol
In the Configuration tab, turn off all turn off all unnecessary audio devices. We will return here later once we’ve set up audio modules in PulseAudio.
As we’re feeding PulseAudio through JACK, it’s important to install the following PA module: sudo apt install pulseaudio-module-jack. The configuration files for PulseAudio have JACK instructions embedded in them already. This will allow you to add virtual cables to customize JACK the way you want.
Cadence is an all-in-one type of application by KXStudio that acts as a Front-end for JACK, ALSA and LADISH. However, LADISH is now deprecated and has been for several years. The replacement to it is New Session Manager (NSM). Catia is the only application in the KXStudio suite which supports NSM.
Navigate to the KXStudio Repositories and follow the instructions on how to add the necessary repos to install Cadence.
Download the .deb for Cadence. It will include all the tools, Carla, Catia and Claudia. Install Cadence
Open Cadence and follow the instructions below to have JACK start when you boot your PC.
Auto-start JACK or LADISH at login
... and select the appropriate Studio.Export hardware ports + Start with Jack toggled on.Configure:
Ignore all self connect requests. This option is bugged. See Claudia on how to circumvent this.Duplex Mode.System Checks, if you see that your user hasn’t been added to the audio grounp automatically (there’s a big red No sign) you can enter the following command: sudo adduser {insert username} audio. On your next reboot, there should be a green checkmark.The following page on the Arch Wiki does a great job explaining how to add audio drivers to PulseAudio: Arch Wiki PulseAudio Examples
We add some extra sound modules in PulseAudio to allow us to separate and reroute sound from certain applications through Jack_Mixer and back into our Speakers. This is particularly useful for streaming, podcasting and whatnot. You can now route your music, radio, voice calls, etc., through your Microphone which would otherwise not be possible through PulseAudio alone. Navigate to /etc/pulse/ and add the following lines in default.pa (You may need to run as root):
load-module module-jack-sink client_name=WebMusic_OUT
load-module module-jack-sink client_name=Discord_OUT
load-module module-jack-source client_name=Discord_IN
I typically place these after the line saying “Load these modules statically”.
The Discord_In is useful for when you want Discord calls to be able to listen to your music or desktop audio through your microphone.
Add more as needed. Remember that an Output (Sink) is where the sound would come from, whereas the Input (Source) is where the sound is going into.
In order for to see if you’ve created the audio cables properly, run pulseaudio -k in your terminal. Check to see if your newly created cables appear in your sound devices menu. Otherwise, reboot your PC.
Jack-Mixer is just that – A volume mixer for your sound devices. It’s a great way to feed your connections’ inputs and outputs in Claudia. However, it’s not exactly the simplest thing to configure.
Jack-Mixer may be available through the APT repos if you’re using a debian-based distro. You can install it easily with the following command:
sudo apt install jack-mixer
Otherwise, follow the instructions below to install Jack-Mixer.
Start by checking your Python version using Python3 --version. If it’s close to the current release, you’ll be fine. You may need to also install pip if your distro doesn’t currently have it:
sudo apt update
sudo apt install python3-venv python3-pip
python -m pip install --upgrade pip
Then, follow the instructions to install Jack-Mixer: For Ubuntu/Debian based distros
On the documentation for Jack-Mixer, python3-appdirs, ninja-build, and gettext are forgotten. If we don’t install these, we get errors during the build steps. Or at least I did. On top of the dependencies and requirements from the Jack-Mixer repo, I recommend installing the following as well:
sudo apt-get install python3-appdirs ninja-build gettext
Once it’s all installed and running, configure Jack_Mixer and add inputs for the speakers and microphone. Add additional inputs for your other programs (the ones for which you created modules in you intend on connecting separately (such as Discord, Google Voice, Spotify, etc.). Save the config as config.xml under the path ~/.config/jack_mixer/
Claudia is a visual front-end for LADISH connections. It allows you to connect your audio devices to one another. It also allows you to connect Equalizers and Mixers, such as Jack_Mixer, and saves your connections as a studio so they can be loaded when you start JACK.
In Claudia, add a custom application and add the following in the command text box:
jack_mixer -c ~/.config/jack_mixer/config.xml
Do not toggle the Run in terminal option. Leave at Level 0. Jack_Mixer will now run automatically everytime we start our Studio in Claudia. As our studio also begins on system startup, so will Jack_Mixer.
Connect your inputs and outputs as you see fit. Once all your connections are setup, go ahead and save your Studio. You can then have your studio start automatically when JACK starts (See Step 1 in Configuration).
There is currently a bug in Cadence which ignores the Ignore All Self-Connect Requests option in the settings. That means that everytime you start up your studio, your connections will be reset and you will see connection all over the place. The current workaround is to modify your Studio .xml file. This workaround gets reset every time you save your studio. It’s best to do this once all your connections are finalized. Navigate to ~/.ladish/studios/, then open your Studio .xml file. Add an a in the <parameter path="/engine/self-connect-mode">a</parameter> line. The a tells Cadence to ignore all self-connect requests. Save and exit the config file.
Catia is a similar application to Claudia, but is used for the current session only. When you restart your PC, all connections made under Catia are lost. If you want to save your connections, it’s best to use Claudia.
As mentioned previous, Qjackctl is a light-weight JACK tool which accomplishes many of the same functions as KXStudio. However, it’s not as feature-rich. At the time of writing, my needs don’t require me to use more than this.
To install, simply run the following command through the APT repos:
sudo apt install Qjackctl
Qjackctl has a few options: a Connections tab that looks a lot like Catia (Which only works for the current session), a Patchbay which persists whenever you reboot your PC (this is the one you likely want) and a Session, which is a sort of mix between Connections and the Patchbay.
Once you click on Setup, you’ll want to configure it to your liking. Here is how I’ve set mine up:
Samplerate: 48Khz Frames/Period: 1024 Periods/Buffer: 2 Realtime: checked Driver: alsa
Self connect mode: Ignore all self connect requests Then set your Output/Input devices.
I’ve checked the following boxes:
Instead of modifying the /etc/pulse/default.pa, you can create a bash
script which will create the JACK audio modules in PulseAudio and which
will run at system startup.
Create a bash script:
vi jackpulse.sh
Then copy the following text:
jack_mixer -c ~/.config/jack_mixer/config.xml &
pacmd load-module module-null-sink media.class=Audio/Sink sink_name=pipe_sink
pacmd load-module module-null-sink media.class=Audio/Sink sink_name=WebMusic_OUT channel_map=stereo
pacmd load-module module-null-sink media.class=Audio/Duplex sink_name=DISCORD_IN_OUT channel_map=stereo
pacmd set-default-sink pipe_sink
This creates a default sink/source for your default speakers and microphone. It also creates a few audio cables for my browser / Spotify, and another for Discord. Finally, it sets the first cables as my default ones.
If you have a headset like I do, then you may want to be able to route some software solely to your headset (like Discord), and others to your speakers. The alsa_out line creates another audio cable to your soundcard found in your headset. Keep in mind that JACK does not “support this” as it may cause some audio to be delayed after a while, but the option is there.
In Qjackctl, toggle Execute script after Startup and add the script
you just created. If you have a Scripts folder for example, you can
input something that looks like this: /home/<username>/Scripts/jackpulse.sh
If you run all your devices through JACK-MIXER for example, and you want it to start with Qjackctl, you can toggle the Execute script on Startup, and input something like this (based on the instructions above in the JACK-MIXER segment:
jack_mixer -c ~/.config/jack_mixer/config.xml &
The & is important so you can continue to perform actions w/ Qjackctl.
You’ll also want to toggle Activate Patchbay Persistence once you’ve configured your connections to your liking and saved the session so you it starts whenever you boot your PC.
If you want JACK to start on system boot, simply add Qjackctl or Cadence (depending on the option you choose) to your startup applications.