Spotify - how to add 2nd pair and play music through both

[alandbush]

OK, I found out how to do it from the DESKTOP version of Spark, but not the Android version.

In the Android version select the ROOMS tab.
Then select, hold and drag the icon of the room that you wish to move into the room that you wish to join.
Similarly, to eject a room, select, hold and drag it to the EJECT bar that appears under that room.