The reason I didn't do this is that the raw C-string is freed once group goes out of scope and I didn't want to check that every use of the string was safe (didn't hang on to the pointer) in EngineMicrophone/EngineAux. I just looked though and everything seems fine but it doesn't protect us from future developers storing the C-string expecting it to last forever. 

Can you just strdup it for now (and leak the memory) and add a comment that all groups should be QStrings someday instead of ```const char*```?