An example method includes, based on an adjustment to a first displayed volume control, instructing the first playback device to adjust playback volume level; based on an adjustment to a second displayed volume control, instructing the second playback device to adjust playback volume level; after sending the commands, instructing the first and/or second playback device to process an audio stream into a first and/or second channel and to reproduce a respective one of the first and second channel, wherein the grouped first and second playback devices provide multi-channel sound; and based on an adjustment to a third displayed volume control, instructing the first and/or second playback device to adjust a group volume level for both the first and second playback devices.