USB-audio using PipeWire on F36 adds 20ms latency to Jamulus


These days, I have been trying to get Jamulus (an online musical jamming program) running with a tolerable delay. Using Fedora 36, PipeWire and an 8-channel USB-audio interface, I started with about 90ms.

I asked the Jamulus people for help (see this issue on GitHub) and got it down to about 45ms. That’s not bad, but it could be much better.

One of the folks said:

Looks like there’s around 20ms extra latency coming from somewhere.

Can someone help me find the cause for this unexplained 20ms additional delay?

These are the specs of my setup (output of inxi --system --audio):

  Host: WaanzinsPC2 Kernel: 5.19.9-200.fc36.x86_64 arch: x86_64 bits: 64
    Desktop: GNOME v: 42.5 Distro: Fedora release 36 (Thirty Six)
  Device-1: Intel Xeon E3-1200 v3/4th Gen Core Processor HD Audio
    driver: snd_hda_intel
  Device-2: Intel 8 Series/C220 Series High Definition Audio
    driver: snd_hda_intel
  Sound Server-1: ALSA v: k5.19.9-200.fc36.x86_64 running: yes
  Sound Server-2: PipeWire v: 0.3.58 running: yes

Frans-Willem (FWieP)