I used something different. Basic details for your entertainment/edification/comedy source material follow mostly so you can shortcut a comparison if you're building something at your place.
2) Class D amp, Aiyima, Fosi, Loxjie etc Aliexpress is one place to get these. I've used and like Aiyima A03 and their ali store delivers fast.
3) Some nice, high-quality, 2nd hand speakers you like. Wharfedale, JBL, B&W, Acoustic Research, Yamaha. (Or get some active speakers you like and skip #2, eg B&O beolab 6000)
5) configure owntone with your spotify premium, takes less than a minute. (And with your music that you own - takes longer because you take more care).
You now have a multiroom setup with fantastic sound that you can control with http://owntone.local:3689/ including with your phone. And/or you can use the "Retune" app on droid and apple's "itunes remote" app on ios. Better sound than most alternatives for less dollars.
All integrates well with Homeasistant because of course it does.
I really like how mine turned out. Having half a dozen sets of speakers all playing the same music in perfect sync as you move from one room to another while doing chores on the weekend fills me with more joy that I would have guessed. YMMV.
I’ve a similar setup but added a dedicated DAC. Honestly not sure I could tell the difference, only got it because I read the built in DAC is not the best. Could be worth looking into if you care about great sound.
Not sure I understand the question. If you have airplay speakers something has to send music to them? Airplay 1 does multiroom just fine and always has.
Owntone on your local network gives a nice persisten connection to whichever speakers you decided to switch on. The music signal is not being relayed from your phone to the speakers so it doesn't degrade as you move about doing your thing.
You control owntone and tell owntone, enable the speakers in the bedroom, livingroom and deck setting each volume separately and play this m3u playlist of your music, or this album, or this spotify playlist or podcast or whatever to all of them at the same time, synchronized.
Owntone does the job of the apple music/itunes software on a mac (ie the software that ships with a mac laptop to play mp3 files), which does multiroom to airplay 1 speakers. Iphones don't do this and don't do it with spotify. I mean not even an iphone to an appleTV plugged into an amp does spotify reliably. Apple's phone controlling an appleTV box requires constant reboots to function which is enough to stop anybody from using spotify with that setup. Is that intentional? Spotify clearly think so. Doesn't look good but I don't have deeper evidence than these observations of what works and what does not.
Owntone development isn't being controlled by apple for their business interests, eg it does spotify, lastfm and works like apple doesn't in my experience of it with the stuff the devs wanted to work (get involved and hack it to your needs if you have more?) - whatever you think is the reason the apple software not working, it clearly doesn't and owntone does. It works controlled from android, or your laptop, or your desktop, or tablet with the music you want not what apple "allows" or "cares enough to not have be broken" or insert some other excuse (maybe there's a convincing one but I can't think of it).
orange-pi zero 2 boxes attached to wifi or ethernet for input and output to class D amp and speakers, also have to power them. You put the pi's running shairport sync where you want the speakers.
Eg plug the pi into power and the amp, plug the amp into power and the speakers. No other wires.
They all synchronise perfectly over wifi or ethernet, which is the point of shairport-sync. They identify themselves on your network as AirPlay 1 speakers. Note that they actually work with the spotify app directly in a reliable way just like AppleTV doesn't - your AppleTV will require a reboot every time you want it to be the output of spotify. So either I'm a better engineer with off the shelf parts and open source software than apple's full time paid professional engineers or maybe Spotify has a point when complaining about Apple non-competitive behaviour? I wish it were the former but somehow doubt it.
1) Pi-zero running shairport-sync (couldn't get them, got orange-pi zero 2 which works great) https://github.com/mikebrady/shairport-sync. I have a few of these.
2) Class D amp, Aiyima, Fosi, Loxjie etc Aliexpress is one place to get these. I've used and like Aiyima A03 and their ali store delivers fast.
3) Some nice, high-quality, 2nd hand speakers you like. Wharfedale, JBL, B&W, Acoustic Research, Yamaha. (Or get some active speakers you like and skip #2, eg B&O beolab 6000)
4) owntone (formerly known as forked-daapd) https://owntone.github.io/owntone-server/
5) configure owntone with your spotify premium, takes less than a minute. (And with your music that you own - takes longer because you take more care).
You now have a multiroom setup with fantastic sound that you can control with http://owntone.local:3689/ including with your phone. And/or you can use the "Retune" app on droid and apple's "itunes remote" app on ios. Better sound than most alternatives for less dollars.
All integrates well with Homeasistant because of course it does.
I really like how mine turned out. Having half a dozen sets of speakers all playing the same music in perfect sync as you move from one room to another while doing chores on the weekend fills me with more joy that I would have guessed. YMMV.