With Apple macOS Catalina (10.15), their latest release, I was surprised to see the volume on my external speakers could not be adjusted within the operating system or by the keys on my Bluetooth keyboard.
The speakers go through my 4K monitor via a 3.5mm jack. The monitor is connected via HDMI to my Dell Thunderbolt 3 port replicator. The port replicator powers my MacBook Pro 13 via Thunderbolt 3.
Doing further research, it turns out macOS doesn’t support volume control with external devices. Instead, I have to figure out how to physically access the volume control. Or I can use a “hack”, like SoundFlower, to intercept the signal and adjust the audio level. This was unexpected and is strange, especially given the removal of audio jacks on computers (which is fine – I prefer to use a port replicator to minimize connecting devices, especially with multiple computers sharing the use of the port replicator). It is odd the other operating systems support such a user-friendly feature (and for the longest time), while Apple does not. What gives? It is time to provide users with an obvious user experience.