Can one stream sound to a pair of speakers connected to Apple TV, while the television is off? I'm thinking of connecting the speakers to the Apple TV via the optical audio port, so that nothing goes through the television, except the HDMI from Apple TV of course. I'm asking because my current setup is: AirPort Express for AirPlay, Time Capsule for backup and Apple TV for entertainment. As you can see there is a slight overlap here somewhere, I'm hoping to remove the AirPort Express while still not needing to turn the TV on. Thanks.