Prevent Display Sleep while there is a audio output

Estartu wrote:

The Mac Mini Speaker is really crap. My Display Speakers a really good. I do not want to listen to music on the Mac Mini Speaker. I do it all the Time on my Display Speakers.

As for the Test. What are to aiming at. Yes I will hear the sound when the display is of. But as I said, it's no fun.

Regards

Estartu

Right, I understand — you want to keep using the display’s speakers but prevent it from sleeping while audio is playing.

Unfortunately, macOS doesn’t treat “audio playback” over a USB-C display as an “activity” that keeps the screen awake. On older Intel Macs, the behavior may have been different due to how the GPU and audio drivers handled USB-C displays.

You could try one of these workarounds:

1. App-based approach: Use an app like Amphetamine or KeepingYouAwake and set a rule to keep the display awake only when specific apps (like Music or Firefox) are playing audio.
2. Script approach: Use a small script or automation that runs a caffeinate command while audio output is active, and stops it when silent.
3. Feedback to Apple: Since this seems like a regression from your Intel Mac, you might want to report it via the Feedback Assistant app — Apple may adjust this in a future macOS update.

System Setting >> Lock Screen on left panel

Change the setting to " Never "

This issue a I see it ( no pun intended "

The Sound Output is being sent to the Displays builtin Speaker

As a Test

Keep your Display setting as they are

Change the Should Output to the Internal Speakers of the M4 Mac Mini