Can anyone tell me why there is no speaker balance control enabled for the optical out setting on the Mac? I have Z5500 Digital speakers and the sound output is terrific, but the layout of my room has me offset from centre and my back is beginning to ache from leaning towards the furthest speakers to get the sweet spot. I could add an amp with a balance control, but that seems to be a bit of an overkill. If it can't be done in OSX does anyone know if there is an app somewhere that gets around the problem?