To produce music for the games I'm writing, had to get set up for GNU/Linux pro-audio. I installed the KXStudio repos on a vanilla Ubuntu 16.04 install on a Lenovo T520, and ran into 4 issues before I had a comfortable set-up and audio functioning. Some of these may apply to you, so hopefully my info on how to solve them could help you out!
In light of these issues and other paper-cuts, I'd highly recommend instead installing the KXStudio distro on a separate partition, which is what I ended up doing in the end. Click here for my original post which talks a bit about that process.
Issue #1: User not in audio or realtime group
My Issue: Cannot create a session in Ardour
Solution: Add your user to realtime and audio groups.
The first thing I tried to do was create a session in Ardour. It immediately failed and crashed, saying that it could not create a new project. The error message made me think it was file-permission related, but it actually had nothing to do with it: Between helpful JACK documentation and reading old Ardour forum threads, I figured out that it can report this error when the user is not in the realtime and audio groups, which can be fixed as follows:
sudo usermod -a -G realtime $USER
sudo usermod -a -G audio $USER
($USER gets auto-substituted for your username.)
Issue #2: JACK is not started
My Issue: Started Claudio session manager, and it said it couldn't connect to JACK.
Solution: Start JACK, just type jack_control --start
This is an obvious one, but for some reason I thought JACK would autostart by default with the KXStudio repos, which is not the case. Howwever, KXStudio does provide a few nicer ways of tarting JACK:
- Use Cadence - this is what I use, it's a GUI control panel for monitoring and managing audio
- qjackctl - popular older GUI solution
- Ardour can start and manage it automatically.
Issue #3: Pulse audio not killed, no MIDI
My Issue: Claudio starts, but it doesn't show hardware MIDI
Solution: For me, the issue was pulse audio was still running. Kill it pulseaudio --kill
You'll probably want a more elegant solution to disable it permanently.
Issue #4: JACK's ALSA output not hooked up to the audio
Issue: Everything seemed fine and I could route audio through JACK, but nothing came out of my speakers or headphones.
Solution: For some reason JACK wasn't hooked up to my hardware.
I personally solved it using the KXStudio JACK manager Cadence as such:
- In Cadence, click the "Configure" button
- Now click "Driver"
- Then click "ALSA"
- Finally, look at the option Output Device and select the one that makes sense
My conclusion for pro-audio on Linux (and maybe in general on all platforms): keep a separate partition, hard-drive, OR computer with your pro-audio set-up, running a distribution dedicated to audio. This may sound like over-kill, but its actually less effort in the long-run.
Check out my first post on this if you are curious.