Rendering to Google Home speaker groups no longer works

[Jesse Pelton]

For years my speaker groups (consisting entirely of Chromecast Audio devices) worked well with BubbleUPnP. They still work from Chrome on a Mac or from a Google app like Google Podcasts on my phone, so I've got them set up correctly, but several months ago they stopped working with BubbleUPnP, perhaps as a result of Chromecast changes required by the outcome of the Sonos suit against Google.

When I cast to the group from BubbleUPnP, only one speaker plays the audio. The others beep when I adjust the volume, so they're communicating, just not getting the desired audio.

Is anyone successfully using BubbleUPnP with Google Home speaker groups? Does the app need to be updated in some way?

[Bubblesoft]

Hi,

Playing to a group of 2 Chromecast Audio (CCA) works fine here on my setup.

Though when testing, I had a weird issue on one of the CCA, were only 1 of the (stereo) speaker was outputting audio.

I fixed it going into the Home app, tapping the CCA, gear icon, tap 'Audio', and disable and re-enable the 'Dynamic Range' settings.

Do you have only Chromecast Audio devices in the group, or mixed devices ?

[Jesse Pelton]

Only CCA devices. There's a Polk Audio soundbar on the network whose firmware apparently isn't being updated, but it's not part of the group. (I haven't even added the device to Home.)

Incidentally, when I said "only one speaker," I was using "speaker" as Google Home does, meaning one or more physical speakers connected to a CCA. In my case, all of the CCAs are connected to stereo speakers, and both speakers in each pair are working when I cast to that Home speaker.

Would logs be useful?

[Bubblesoft]

When you play to a Chromecast group in BubbleUPnP, the group is entirely a black box for the app:

from its POV, it plays to a unique renderer and it is Google magic that actually plays to multiple CCAs of the group.

That's why a log file would not help as the app doesn't know if individual devices of the group are actually outputting audio or not.

I suppose you may already have looked at that, but when you play to the group (and only 1 CCA is outputting audio),

start the Google Home app and verify that the volume of the silent CCAs of the group is not 0 or muted.

Also, you can try to delete the group and recreate it entirely, just in case it fixes the problem (although unlikely).

[Jesse Pelton]

I have indeed checked the volume on each speaker. Furthermore, if I adjust the phone volume while casting to the group from BubbleUPnP, I hear the volume adjustment sound on the speakers that aren't playing the cast audio. Really weird.

I've been through the whole delete/recreate cycle several times. Most recently, I reset all the CCAs, uninstalled Home, restarted the router, reinstalled Home, added the devices, and recreated the group.

Maybe this is relevant. If I tap a speaker in Google Home, a "Cast my audio" button appears below a volume control for the speaker. If I tap a speaker group, though, there's no option to cast to the group. The only way to I've found to cast to a group is from an app that supports casting like Google Podcasts. Are you able to cast to a group from Google Home?

[Bubblesoft]

I do not have "Cast my audio" button for the group as well.

No idea what is causing this issue, as I cannot reproduce it on my system.

The whole group casting is a black box to me and the app.

[Jesse Pelton]

I've tried some other apps. One worked fine if I started casting from outside the app (by telling Google Assistant to "cast my phone"). Another with built-in casting support behaves the same as BubbleUPnP. YouTube Music, which says "Sorry, you can't cast device files" when I try to cast music from my library from within the app, but if I start casting outside the app, it works fine.

In short, it's all a mess, and everything indicates that it's Google's mess.

One more question: when you cast successfully from within BubbleUPnP, are you playing audio from your device or from a streaming service?

[Bubblesoft]

Playing locally stored mp3 or flac, browsing the Library tab, 'Local and Cloud' Library.

[Jesse Pelton]

I ended up installing a simple app called Cast Shortcut. It makes it about as easy as possible to start casting your phone. (There are a number of apps that look like they do something similar, but this one worked for me, so I didn't try any others.) Then I run BubbleUPnP using the local renderer and all the speakers in my group play the audio. Maybe the same will work for other BubbleUPnP fans who find themselves in my predicament.