I would like to have different groups of sounds in such a way that I can set a different volume for each group. I am now creating several AudioManager instances. However, when I call myAudioManager.setVolume(0.5) I get the warning:
:audio(warning): FmodAudioManager::set_volume has no effect.
which seems to be right, cuz I hear no difference 
. Is there a fundamental reason why set_volume has no effect or has it simply not been implemented?
Alternatively, could I achieve the same thing in a different way?