I'm running SPAN in Rogue Amoeba SoundSource 4 (https://rogueamoeba.com/soundsource/) but it seems that there's an issue with routing configurations.

1) Set Routing to Mid-Side Stereo (the Mid channel is selected by default here)

2) Hit Solo to try and solo the Mid channel - it has no effect, the full stereo signal is still heard.

Same thing happens on pretty much all Routing options.  Any idea on how to get this working correctly?

I contacted the developers and their response was:

"The way the Span plugin is currently designed, it's not fully functional with SoundSource.  If the plugin developer is able to make an update that ensures the Solo setting is stored by the plugin, then it should work better with SoundSource."

Is this something you're able to address in Span?

That's the thing though, I'm trying to use it for real time audition of the Mid / Side channels whilst also seeing the spectrum in Mid / Side mode.  Using the MSED plugin can't achieve this because Soundsource only lets you see 1 plugin GUI at a time.

Soundsource is a super useful tool for inserting AU plugins into the Core Audio signal path between your DAW's output and your audio hardware, for monitoring purposes.  So basically you can use SPAN (or other plugins) across all audio going to your soundcard - your web browser, Spotify, Apple Music, everything.  It's very handy.

Being able to properly use SPAN with the app would be amazing and very useful, is there any way you can possible implement what's needed here?

No I'm just trying to use SPAN to see the FFT plot of whatever's playing back through my interface in Mid / Side mode, and also be able to solo the Mid / Side channels at the same time.

In my use case I definitely don't need it to recall its state from session to session, I definitely prefer SPAN opening to the default setting I've saved for it, and then I can switch to Mid / Side mode only when necessary (which is not all the time).