Got 2 players running with the amazing Infineon MERUS HAT. One on the left speaker, another on the right speaker (BTW: MERUS is missing in the GUI setup, but adding the line “dtoverlay=merus-amp” in config.txt fixes that). Both players have the Spotify 2 plugin.
The two players can be grouped into one. So one player seems to be the “master” and when selected in Spotify, music comes out on both speakers. So far so good.
But. How to get the volume control in Spotify to control the volume (on both left and right players at the same time)?
The only way to control volume I have found so far is to go into the “Zones & Output” window on the app and tap both volume sliders (very difficult to adjust as they are quite small).