Audio sync problem with multiple HomePod after update to IOS18

Hello good people!

After months of audio problems with HomePods and AppleTV, iPhone or AirPlay—it’s hard to say exactly which—I’ve finally found a solution. I’ve tested it for a while now, and there are NO issues regardless of the app or device. I’ve tried it with Apple Music and Spotify in AppleTV and iPhone, and it now works flawlessly. I should also mention that I’m running the iOS 18.4 Developer version on all my devices. The problems I experienced were crackling sounds or sync issuesafter a while as I tried playing on multiple HomePods in the home, usually playing on different HomePods in stereo pairs, and the speakers in the stereo pairs losing sync.

Now for the solution. In my case, it was IGMP/multicast-related. My switches had IGMP snooping enabled—as did my Asus WiFi(Mesh) routers—but they only had IGMP snooping activated on WiFi. I had to enable multicast routing on the LAN as well. On Asus devices, you can find these settings under Wireless > Professional and LAN > IPTV. Now everything works perfectly again.

Hope this helps someone find a solution.

\Dan

Hi, Since you have multiple HomePods, the issue might be related to Wi-Fi signal strength. Some HomePods that are farther from the router may experience weaker signals, causing the delay.

Try grouping all your HomePods closer to the router and test again. If the problem persists, follow these steps:

Possible Solutions:

• Restart your router

• Restart all your HomePods

• Sign out of your iCloud account and sign back in

• Check if your devices need software updates

• Ensure all HomePods are connected to the same Wi-Fi network

• Unplug all HomePods, wait 2–3 minutes, and plug them back in

• Toggle the Lossless Audio option in your iPhone settings and the Home app

• If your router supports both 2.4GHz and 5GHz bands, try connecting all HomePods to 5GHz. If that doesn’t help, switch to 2.4GHz

Alternative Solution:

• Reset all your HomePods

• Reset your router

Let me know if any of these steps help!

I’ve been doing several tests. I reset all the HomePods, but it didn’t solve the issue. I disabled Atmos and Lossless, but the same errors persisted. What I noticed is that it seems to be related to the iPhone. On the iPhone, the issue only affects Apple Music when trying to stream to multiple HomePods. When I stream via the Music app on my MacBook, this error doesn’t occur. I haven’t tried performing a factory reset on the iPhone yet.

I had already disabled Dolby Atmos without improvement. I disabled Lossless and after 1 days full operation it was better. Using 1 Homepod Gen2 and 1 Homepod Mini stereo pair playing together all day without sync issues. Adding in 4 other Homepod Mini's did result in sync issues. I doubt Lossless is a significant quality loss when using Homepods but this would be a quality loss for uses using Apple Music through a hifi music streamer. For me being able to play our main room HP and Mini pair is a workable solution. Obviously there is a problem with HP's being able to stream more then 2 units with Lossless enabled and more then 3-4 unit with it disabled. At least for me. I'll update again after using the non-Lossless setting for a few days. Cheers!

My stereo pair HomePods had the same issue and 18.2 fixed it.

This issue was happened in 16.0-16.1/17.0-17.1/18.0-18.1 and fixed in 16.2/17.2/18.2.

Apple, please test stereo pair before updating OS.

yes, playing from thye iphone apple music app will cause multiple HomePod out of sync every 2-3 songs. But when play from the Apple TV app….. the problem is gone!!! Have no explanation to this….

Very likely this issue has to do with Wi-fi coverage in your house.

In most Wi-Fi routers, you can check their admin interface to learn about the connection speed of any Wi-Fi device. This could be a step toward troubleshooting this. Find your HomePod's in the admin interface and see what connection speed they are on. You'd want to look at the following:

TxRate: (Transfer Rate). This should be a rate above 50 Mbps. Ideally something more like a few hundred Mbps to be sure there is plenty bandwidth to stream uninterruptedly.

18.2 fixed - at least for now - the issue where the song would end early, then the next one would start a few seconds in, stop, and then start at the beginning. But the sync issues are much worse. I tried assigning all the one on the same level to the same room, which has helped some, but they still go out of sync after about 10-15 minutes. Which is an improvement on the 1-2 minutes it took before I reassigned them.

My setup - one stereo pair of HP2, two unpaired HP2s, and three minis in different rooms. Small house, but a very sound-sensitive person so no one speaker can be loud enough to hear in a larger area. Playing my own music through Apple Music.

I have disabled lossless and Dolby. That solved the problem for me.

If they aren’t working as they should, a restart is your best option to resolve this. You can restart them via the Home App or unplug for 10 seconds to restart them.

have a pair of HomePod mini (gen 2) as default audio pair on AppleTV 4K (gen 1) all running iOS / tvOS public betas. I also have a gen 1 HomePod which I like to use as a “bass extension” for the pair of minis.

Playing the gen 1 HomePod alone, no problems. Playing gen 1 and gen 2 HomePods at the same time, the gen 1 gets further and further out of sync and soon the gen1 starts making horrible “BUUU.UUU.UUUUUUU.PPPPP.PPP” farty noises.

disconnect the gen 2 HomePods, gen 1 sounds as good as new.

Still happening to me with 18.2. But the problem is just with Apple Music. I’m testing with Spotify and youtube and no problem at all. I have 2 HP 1st gen in stereo, 1 HP 1st, 2 mini in stereo and other 2 mini singles and all of them have the same problem when put together playing.

For those who, like me, were hoping 18.3 would fix the sync issues, the answer is no. I had switched over to playing my downloaded music from my Mac instead of using Apple Music streaming. Still the very occasional abrupt end and false start, which setting the slider back to the beginning of the song fixed for another day or two. But no speakers going out of sync several times an hour.

My free trial of Apple Music ends on February 27. Unless this has been fixed by then, I'm canceling it before then. If I see from these boards that a future release has fixed it, I'll subscribe again. Yes, I have all of my pre-subscription music saved, so I won't lose anything.

Maybe someone else has better news?

This issue occurred for me since v17.x. Still occurring with 18.5 but maybe a bit less often... still occurs multiple times a day. Have to either restart the current tune, skip to next tune, or pause and then un-pause current tune to resolve the sync issue.

iTunes Remote app - how did I not know about this?

Okay, so I subscribed to Apple Music only because I want to be able to control what is playing from all of my and my family's devices. I only play the music that I have ripped from CDs or downloaded.

But the sync issues have been so bad that I ended up only playing from my Mac, which meant I could control it only from there.

But... maybe I'm late to the party, but why isn't iTunes Remote (Apple app) more widely known? I set it up yesterday on all of our devices, and now we have the same controls we have when playing through Apple Music. Volume, which HomePods to connect, and even change the playlist. The only thing it doesn't seem to work on is the other Macs. It will show what is playing, but there are no controls. But that is also true with Apple Music.

I hope this helps someone who is struggling with sync issues.