Question

Within the group settings, the Group Graphic EQ works allright but the Relative Group Volume +/- keys have no effect on the level, despite the visual level changes, there is no audible effect on the sound.

Room Control for iOS on an iPad, version 1.1.3 on iOS 10.0.1

Answer 1

In each individual speaker setting page you must enable the speaker volume control for the Group Volume to affect it.

As a start point, set Group Volume to 0db then go to each speaker in turn and enable the volume control ensuring it is also set to 0db.  If the speaker levels are unbalanced you can turn down the ones which are to loud here.

Any change you make to group volume will affect all the speakers proportionately, but it does it by adjusting the individual speaker level, it's not a separate control.