Maybe it's just fond memories from a long-ago era, but didn't the original Airport Express have multi-room audio? I remember it working quite well.
How is this a feature, 15 years later?
How is this a feature, 15 years later?
However, you can't really do that with a phone, since it eats battery and needs a stable wifi connection.
AirPlay 2 solves that by allowing the phone to buffer minutes of audio to one speaker, which then distributes that buffer to the rest of the speakers.
I just remember that chromecast's protocol was actually unusable on a slower connection.
The problem is synchronizing the streams, not the bandwidth used by an MP3.