Audio Crackle und Linux

Hello forum,

after years of only using Linux for Servers I wanted to use it on a Deskmini for general computing and I experience audio crackle at random moments in playback. Had the exact same problem with 2 distros (Fedora 41 and Tumbleweed). Crackle Appears independent of software used for playback.
Currently running Tumbleweed with KDE under Wayland.

Hardware:
Presonus Audiobox USB (confirmed to not crackle under Windows, OSx and Linux years ago using Jack and Alsa)
Asrock Deskmini X600 (latest bios)
AMD 9700X

What I’ve done so far:
Disabled USB autosuspend (via sysfs and udev rule)

Set PipeWire buffer config:
clock.rate = 48000
quantum = 1024
Confirmed via pw-top that the values apply

Created WirePlumber rule targeting the AudioBox to apply:
period-size = 1024
period-num = 4
headroom = 512
node.latency = 1024/48000

Enabled realtime audio limits:
Created systemd user overrides for pipewire.service and pipewire-pulse.service
Set LimitRTPRIO=95, LimitMEMLOCK=infinity, LimitNICE=-11
Verified with systemctl --user show pipewire that these limits are in effect

Switched CPU governor to performance

Locked sample rate to 48000 across PipeWire to avoid resampling

Confirmed realtime priority working (ulimit -r is 95 for PipeWire, not for shell)

Despite all that, the crackling persists. Happens even under low CPU load, and pw-top shows no underruns. Tried different USB ports. Audio crackles in everything, not just one app.
The crackling is not part of the audio files.

Of course I already searched the internet and found a lot of people with the issue but for a lot of them it never resolved.

I am a bit disappointed to be honest because a decade ago even with PulseAudio which was garbage at least the audio did not crackle with the same output device. Since I am not planning on doing audioproduction on this device (thank god), I was really not looking forward to mess around with JACK again.

Anything else I can try besides deciding that 2025 is not the year of the Linux Desktop?

And we can close this…
Turns out the Presonus Audiobox does not give a shit if its running on an USB 3.0 port under Windows but under Linux it causes the crackling. The Topping DX7Pro+ which I had lying around did not produce the crackling even with reduced latency.

Presonus Audiobox has a lot of issues, even under Windows. I could red line the inputs with the mic pre’s and inputs on zero. Spoke to PreSonus about it…one of several design flaws. Glad you found a substitute device.