One Echo is good; several is better. Amazon's Echo devices have multiroom audio support, allowing users to simultaneously stream music across multiple speakers, making it feasible for people to outfit their entire homes with Amazon's smart speaker.
The feature lets you play audio from Amazon Music, TuneIn, iHeartRadio, Pandora, Spotify and Sirius XM over multiple speakers. Added Apple Music Support last December.
To set up multiroom audio, open the Alexa app and select Devices. Tap the + icon in the top right, and select Add Multi-Room Music Speakers. The app will then prompt you to create a group, making it easier to control music playback by saying things like “Alexa play music upstairs” instead of calling out individual speakers. Once you created your group (s), add your desired devices and the setup is complete.
Using multiroom audio is as simple as everything else with the echo – just say where you want the music to play. Saying "Play Justin Timberlake" followed by the name of your group will activate the music in your desired location, and so it works flawlessly in my testing.
Now if you like me, you can easily find the use of multi-room audio support – but would like to use it with better speakers, like Sonos for example – you can do that as well. First, you have to use your Alexa app to add the Sonos Skill and discover your Sonos devices. You should also add the music services that you are using with your Sonos system (any music services you need to use on both the Alexa and Sonos apps). You can control your device using Alexa and create groups of products within your Alexa app. (You can also associate with a single Sonos speaker and use your Sonos app to create a group associated with that speaker.)
Amazon has released an API to allow third-party Alexa speakers to operate within the multiroom audio playback setup.
Multiroom audio playback is available to Echo owners in the US, UK, and Germany on Echo. , Echo Dot, and Echo Show devices.