Audio glitching with RME UCX Fireface

[faunchile]

Ubuntu Version:
24.10

Desktop Environment (if applicable):
KDE Plasma

Problem Description:
I am experiencing audio glitches when in general use, listening to Spotify and Firefox. They are irregular, intermittent. At first I thought it was sampling mismatching between, Spotify, Firefox (for example) and the interface, however I have everything set to 44.1khz.

The Linux audio architecture is certainly quite confusing, Pulseaudio, Alsa, Jack, Pipewire, Plumbwire… I guess I’m still demystifying this…

Relevant System Information:
Lenovo Legion Pro 7i Gen 9, 64Gb

Screenshots or Error Messages:

What I’ve Tried:
Removed Pulseaudio to force pipewire-pulse: When Pulseaudio was running with Pipewire the glitching seemed more regular.

Checking that sample rates are matching across the system, ie that I’m not running the interface at 44.1kHz while forcing the system into 48kHz.

Tried plugging into different USB ports to see if I could put it on it’s own bus. However it seems Lenovo USB ports all use the same bus, this was a GPT suggestion and might just be rubbish.

Thanks in advance I could try and record and example of the ‘glitch’ sound if that helps.

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[halogen2]

If you are still using Pipewire for audio, the next troubleshooting step would be to try running pw-top in Terminal and while that is running, reproduce the glitchy audio and see what pw-top shows while the audio is glitching?
(To stop/exit pw-top just press q)

[eeickmeyer]

@faunchile

Removed Pulseaudio to force pipewire-pulse: When Pulseaudio was running with Pipewire the glitching seemed more regular.

Having pulseaudio installed is not part of the Ubuntu Studio audio setup anyhow (as of 23.04, so for two years now). 24.04 can optionally switch to it, but it’s unsupported. In 24.10, it’s not even an option, so I have no idea why it’s even there.

If it got uninstalled, reinstall ubuntustudio-pipewire-config and that should have all you need, meaning PipeWire will just work with anything that’s looking for JACK or PulseAudio.

I have the feeling you’re following some outdated guides you may have done a websearch for telling you to do some lowlatency configurations. That’s no longer necessary. See Ubuntu Studio Audio Configuration – Ubuntu Studio

You might also have to switch the audio interface to the “Pro Audio” profile (you can do this in the hamburger menu for each device, shown below), which forces PipeWire to run it without sample rate translated, which is something PipeWire does by default.

For casual use, you really should be using the default (1024 buffer at 48000Hz) since most applications want to use that anyhow. Set that using Ubuntu Studio Audio Configuration by leaving the field “blank” in “Change Audio Configuration”:

Other than that, I am not familiar with that audio interface, so I cannot help with that. However, here is a list of compatible audio interfaces/cards and their drivers: https://www.alsa-project.org/wiki/Matrix:Main. It’s pretty extensive, but not exhaustive.

Taking a cursory glance at your interface, it appears as though it requires special drivers when used on macOS. This gives me the impression it is not a class-compliant device and is, therefore, not guaranteed to work with the Linux kernel. For what it’s worth, I have a Behringer Uphoria UMC404HD and a Behringer UMC22. Both work perfectly with Ubuntu Studio as both are class-compliant device. RME has other interfaces that are class-compliant, but yours doesn’t appear to be so.

@faunchile

this was a GPT suggestion and might just be rubbish.

Yeah, blindly following those instructions isn’t a good idea. Luckily you’re in the right place.