I have a Raspberry PI5 and am trying to use an Auracast bluetooth dongle connected to a USB audio interface (actually I’ve tried 3 different ones) via pipewire using qpwgraph. If i connect the dongle and the interface to the PI directly I get a lot of white noise coming out the bluetooth receiver. If I put the dongle on a powered hub or a long USB extender the noise goes away. Though very occasionally I get a clean signal when both are directly connected to the Pi. I tried using a high speed USB isolator on the dongle and that didn’t help. if I run pw-top it shows the rate and quantum of the dongle to be 0. This is the same whether noise free on the usb hub or connected directly to the Pi. I don’t think it is rf noise because when on the extender or hub I can put the dongle over the PI with no interference. I get the sense it is some kind of conflict with pipewire. I’ve tried changing the quantum with pw-metadata with no change. When I run audio from Firefox to the dongle via qpwgraph the rate and quantum for the dongle are reported correctly. If I connect the input of the audio interface to the output of the interface in qpwgraph the sound is good so the noise is coming after the sound goes from the interface into the PI.Anyone have any thoughts on this one?
I discovered if I shut down Pipewire and use the alsaloop command the noise goes away. Still unsure what in Pipewire is causing the issue?
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