Apple recently updated its HomePod software, introducing AirPlay 2 and support for stereo pairing.
I&ve been using these features since they arrived, and this is what I think so far:What are the improvementsApple iOS 11.4 update introduced HomePod 11.4, which brought two significant new features to HomePod systems: AirPlay 2 and stereo pairing support.AirPlay 2AirPlay 2 lets you control music playback around your home using Siri, HomePod and AirPlay 2 supporting speaker systems from third-party manufacturers.
So long as all your systems are on the same Wi-Fi network, you get multi-room playback and controls.