I want to connect 3 devices (my MacBook Pro, new Apple TV, and iPhone 6s) to a "mixer"-like device and then use one pair of headphones to listen to all 3 devices. I'd be able to mute a device at any time and adjust volume as well. Preferably, the "mixer"-like device would have Bluetooth functionality so I could use a pair of Bluetooth headphones. What's the best thing to get for this type of thing? Does anyone know?