Home Technology AirPlay 2 'hubs' vs AirPlay 2 'clients'

Discussion in 'HomeKit, HomePod, CarPlay, Home & Auto Technology' started by Macwick, Aug 29, 2018.

  1. Macwick macrumors 6502

    Dec 9, 2008
    (This is a slightly modified cross-post from the AirPort Express AirPlay 2 news thread.)

    I don't know about everyone else, but it's taken me a while to fully piece together what the AirPlay 2 ecosystem can really do and how we're supposed to use it.

    The promise of AirPlay 2 is multi-room audio - and it (largely) delivers on that. However there are some important nuances about this new eco-system that are worth understanding. There are also some gaps that I think Apple needs to fill to truly achieve this vision.

    First, it's important to recognize that not all AirPlay 2 compatible devices are created equal:
    • iOS-based devices - such as HomePods, iPhones, iPads, and Apple TVs - are essentially AirPlay 'hubs'. These devices can stream audio directly from Apple Music and (in the case of Apple TVs, iPhones and iPads) other online audio sources. Furthermore, these hubs can 'multicast' these streams to any other AirPlay 2 device (whether these devices are hubs or not).
    • Other AirPlay 2 compatible devices - such as the recently updated AirPort Express - are more like AirPlay 'clients'. They can be streaming *destinations* for hub devices, but cannot themselves stream audio directly from the Internet. (Thus far I only have direct experience with the AirPort Express, but my guess is that other third party AirPlay 2 compatible devices (i.e. amps, Sonos, etc.) operate the same way. Someone please correct me if I'm wrong).
    Note that Apple does not explicitly make this distinction - it's not documented anywhere, as far as I can tell. However, it is a meaningful distinction. Why? Consider these use cases:

    If I ask Siri on my iPhone to 'play Foo Fighters in the Living Room' (an AirPort Express). It will stream the music from my iPhone to the AirPort Express. My iPhone is now 'in use' - if I turn it off, start listening to something else on it, or leave the house with it, the music in the Living Room will stop.

    It's slightly better if I ask my HomePod to 'play Foo Fighters in the Living Room', as it will stream the music from the HomePod to the Living Room (and any other destination I specify). This means I can turn off my phone, use it to make calls, etc. However, the HomePod in my kitchen is now 'in use'. If I then ask my HomePod to play something else in the kitchen, Foo Fighters will stop playing in the Living Room.

    Things work much better if you ask Siri on one device to play music on one or more other 'hub' devices. For example, if I ask Siri on my iPhone to 'play the Beatles in the Kitchen' (a HomePod), the HomePod will begin streaming this music directly from the Internet, with no dependency on my phone. Or if I ask my HomePod to play music on my Family Room Apple TV, the Apple TV will begin streaming this music directly, with no dependency on my HomePod.

    Furthermore, I can independently control playback on 'hubs' via the iOS Music App on my iPhone or iPad, and even see lyrics and 'Up Next' there (you can't yet edit the 'Up Next' list for a remote hub, but hopefully this feature will be added at some point).

    As I think I've demonstrated in these use cases, the experience is somewhat inconsistent depending on whether the target device in question is a hub or a client.

    So what's the solution? We're actually closer than you might think. I think that AirPlay 'clients' are fine as a low cost alternative and probably work well enough for most people. But there should be at least one AirPlay 'hub' device on the market (a HomePod lite?) with audio out to support rooms with existing amps - such as built-in speaker systems, outdoor speaker systems, etc. This would allow those of us with these types of use cases (and willing to pay a premium) to realize the full multi-room audio experience - the ability to independently control - from any device - the playback of audio on any other device in the house.

    Would love to hear other people's experience thus far and if they agree or disagree with this assessment (or am I the only one crazy enough to spend this much time and effort on AirPlay 2?!).
  2. brilliantthings macrumors 6502

    Feb 13, 2011
    The only thing I'd add is that an iPhone can make or take a call while streaming to a client without interrupting the streaming.
  3. melancholy macrumors 6502


    Aug 25, 2016
    I don’t believe any other AirPlay 2 speaker will have this ‘hub’ feature that you’re talking about. Because in order for that to work independently, the device will need access to Apple Music on its own, along with other features. Currently no speakers are built to have a brain to run ‘apps’ such as Apple Music, and I don’t believe Apple has given any manufacturers to do so. Unlike Sonos, I believe their hub is run on a local server, whereas Apple uses a device independently and streams the content onto speakers via AirPlay 2.

    The ‘hubs’ you were referring to are also not AirPlay 2, but I guess they are technically hubs. However, they’re just meant for remote controlling your devices, and they happen to be able to AirPlay to and from.

    The AirPlay 2-enabled speakers you see listed beneath the controllers are actually the ones utilizing AirPlay 2. And only those ‘hubs’ stream to those speakers to allow multi-room sounds.

    I’m assuming one of the reasons why HomePod is prioritized first when you say ‘Hey Siri’ is because you are likely to use music commands and Apple would rather have you use AirPlay 2 features (such as multi-room) be streamed from HomePod rather than your iPhone.

    Technically AirPlay 2 isn’t as ‘independent’ per speaker like Sonos speakers are. AirPlay 2 is only meant to allow Siri controls, multi-room sounds, longer buffer times, etc. It’s meant for streaming. To have it’s own ‘Now Playing’ pane in Control Center like HomePod and Apple TV, it needs an actual brain to process and stream those content (like HomePod and Apple TV, and of course iPhone and iPad).

    These ‘hubs’ are actually the ‘source’. And even though HomePod, Apple TV, iPhone, iPad, and Mac are all ‘sources’ for AirPlay 2 speakers, only HomePod and Apple TV show up in the Now Playing panes because they’re HomeKit home accessories, and Apple only allows multi-streaming on home accessories. iOS devices aren’t meant to be remote controlled because they’re not home accessories, and you cannot stream music with multiple iOS devices.
  4. Macwick thread starter macrumors 6502

    Dec 9, 2008
    I'm inclined to agree with you. I think such a device would have to be made by Apple as it would be a full-blown iOS device. This is why I'm holding out hope they release some kind of HomePod device with audio out. This would enable you to have 'hubs' in every room (including those rooms/zones with their own amps)....
    --- Post Merged, Aug 30, 2018 ---
    I agree, but it leads to a pretty arbitrary and inconsistent user experience. Let's say I'm standing near my HomePod (holding my iPhone) and say 'Hey Siri, play Smashing Pumpkins in the basement'.

    If the HomePod picks that up, it handles the streaming (and my phone is free to use). If my iPhone hears it, it will stream the music itself, which leads to a different experience (i.e. if I launch another app with audio, or turn off the phone it interferes with streaming).

    I think that the iPhone should be used as a streaming source only as a last resort (no other iOS AirPlay 'hubs' available).
  5. cynics macrumors G4

    Jan 8, 2012
    I know nothing is perfect however if you are standing near your HomePod holding your phone by your mouth as long as the HomePod can hear you Siri on your phone shouldn't be activated (or quickly deactivated by the HomePods Siri request). The HomePod takes priority over other Siri devices.

    This is the important part though. Be specific! If you specify the room the device is located in it will play FROM the device in that room if that device is capable of it regardless which initial device you asked.

    So I just whispered to my iPhone in my office "Hey Siri play Blazo in the living room" and I have this.


    As you can see my Music isn't playing from my phone its playing from the Living Room AppleTV.
  6. Macwick thread starter macrumors 6502

    Dec 9, 2008
    Yes, all very good points. And you're right - as long as the 'target' device(s) are 'hubs', then it really doesn't matter which device you make the request from - the 'target' device(s) will stream the music themselves.

    Which leads me back to the fact that the only real gap at this point is a 'hub' device that can be hooked up to an external amp.
  7. cynics macrumors G4

    Jan 8, 2012
    I often have the same issue you are having with Apple. Generally I'm overthinking it though, they want to make things simple and somehow they make things so simple it doesn't make sense anymore.

    AirPlay 2 'hubs' (as we are calling them here) can send audio without playing it on themselves as well. Since the HomePod tries to prioritize itself with a Hey Siri command saying "Hey Siri play Foo Fighters in the living room" will make your HomePod in the kitchen (assuming it could hear you say Hey Siri) send the audio to the living room airport express.

    I don't have an AirPort Express or any device that isn't a hub however you will see something similar to this. HomePod -> Living Room, with the arrow indicating the HomePod is sending the audio, obviously HomePod + Living Room means both are playing.


    I could play something different on my iPhone right now or not use it at all.

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