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How to Set a Room for Your Apple TV and HomePod for AirPlay 2 - The Mac Observer
You updated to iOS 11.4 on your iPhone or iPad, tvOS 11.4 on your Apple TV, and HomePod 11.4 on your HomePod so you have AirPlay 2 support. Now you need to assign rooms to your speakers so you can control where you're playing music. Here's how.