Unable to change between speaker and headphones on macOS 12 / M1 Pro machine

• Jan 17, 2022 - 02:51
Reported version
S4 - Minor

Device: Macbook Pro (16-inch, 2021), with M1 Pro; OS: macOS 12.2 Beta (21D5025f).
Application installed via Homebrew and currently running via Rosetta 2.

Musescore "about" dialog report:
OS: macOS 10.16, Arch.: x86_64, MuseScore version (64-bit):, revision: 3224f34

The Bug:
Musescore will only use the system-wide default audio output device at app launch as its audio output device, and any change to the "Devices" selection or system-wide default audio output device have no effect at all on Musescore's audio playback device selection [A] – most prominently, Musescore will not recognize headphones if it is not plugged in before app launch. The only exception observed now is that Musescore will correctly switch to internal speakers if headphones were its audio output device but subsequently unplugged.

Preference → I/O - CoreAudio - Devices shows:
1. only "Macbook Pro Speakers" and "Macbook Pro Microphone", and "Macbook Pro Speakers" is selected – if no headphones were present at app launch;
2. "External Headphones" and "External Microphone" in addition to the above, and "External Headphones" is selected – if headphones were present at app launch and used as system default audio device (even if it is removed afterwards).

Removing the headphone will cause Musescore to use speakers as audio output device, though the "Devices" selection still shows "external Headphones" as selected.

Changing the I/O from "CoreAudio" to "JACK Audio Server" (not present on device and thus disables audio playback) and then changing back to CoreAudio seems to force Musescore to pick whatever the system-wide default audio output again – this means headphones will be used if it is plugged in after app launch and before changing the I/O. The behavior described at [A] persists.

I don't have another audio output device I can test right now, but I will test a USB audio output later if I find one.

This bug in its naive, "it won't recognized my headphones!" form has been reliably reproduced all the time on my machine on macOS 12.1 Beta and the current 12.2 Beta, but the more detailed investigations was done on macOS 12.2 Beta. It was not seen on my Intel-based macs running macOS 10.13 through 10.15.

Workaround I use is simply relaunching the app with headphones already plugged in, but it seems like changing the I/O is a plausible workaround too.