Distorted Audio from RNBO Patch on Raspberry Pi 4 via Headphone Jack
Hi,
I’m running RNBO on a Raspberry Pi 4 and trying to get clean audio output through the headphone jack. I’ve followed the setup guide, and I can now load patches through the RNBO Runner Panel in the browser.
However, when I run a simple sine wave patch from RNBO, the output sounds aliasy and distorted — as if the sample rate is incorrect or the waveform is being bitcrushed. However, other system audio (like speaker-test) sounds perfectly clean. I've triple checked the export bit rate, sample rate, bit depth, within the export settings of RNBO and all seems correct.
Weirdly if I launch JACK manually via terminal with:
jackd -R -dalsa -dhw:1 -r44100 -p1024 -n3
...the sine wave sounds cleaner (though still slightly imperfect), but then I lose control from the RNBO Runner Panel.
Any idea what might be going on? How can I get clean output from RNBO?
macOS Sonoma 14.6.1, RNBO 1.3.4, max 8
Initially the headphone jack wasn’t supported by RNBO. I seem to have a dark memory that it might have changed with some later release. But I am not sure. The same dark memory tells me that Jack had to be started with some special settings/parameters to get it to work…
Hopefully someone else here has a better memory than I
I need to use the "extra args" to specify the number of inputs and outputs for this to work right.
Check out the details of "Jack Extra Args" if you scroll down a bit here: https://cycling74.com/forums/rnbo-132-released
I had the same problem with the distorted sound from the Headphone Jack output of the pi (Pi 4 Model B 4GB RAM).
The problem was solved with "Extra Args" in the audio settings on the Web Interface (Settings -> Audio -> Extra Args). You need to type in -o 2 -i 0 .
It probably has something to do with input/output priority, forcing the Jack Socket to act as an output.
Tho on the RNBO 1.3.2 release forum, theres a link to more Jack configuration options
You can find many Jack configuration options here
but the link seems broken.. I would've love to see more options.
This did the trick! Thanks so much for your help Zak.