Multiroom Audio not always synced

Tagged: Audio Sync, DLNA, LMS, Multiroom, reference signal

This topic has 6 replies, 3 voices, and was last updated 4 years, 6 months ago by Mark-in-Seattle_GMT8 premium.

Viewing 7 posts - 1 through 7 (of 7 total)

Back to forum

Posted in: Max2Play on Raspberry PI
djvj premium

25. April 2020 at 6:22 #48612

I have 3 rooms at the moment.

Room 1: RPi 3b+ with a HifiBerry Amp 2
Room 2: Sonos
Room 3: Firestick 4K with Kodi

Using Group Players plugin, along with the UPnP/DLNA Bridge plugin. I would say about 50% of the time rooms 1 and 2 are in sync and the other 50% they have either the slightest delay or 1/2 second delay. Completely random. Under the Group Players plugin I have „Synchronize to Group Players“ and „Always synchronize all members“ options enabled.

Room 3 is always a good 1-3 seconds out of sync from rooms 1 and 2. Since the rooms are next to each other it’s very obvious when even the slightest out of sync occurs.

Does anyone know what else I can do to get these always in sync? I feel like there’s not much else I can adjust.
- This topic was modified 4 years, 6 months ago by djvj.
MarioM Moderator

28. April 2020 at 14:33 #48636

Hi djvj,

The reason for such synchronization problems is often the internet connection. Did you connect your devices to the internet via WiFi? A LAN connection may help here.

djvj premium

28. April 2020 at 16:41 #48647

Room 1 and room 3 are ethernet. Room 2 being sonos is not. There is an ethernet connection right there I can test temporarily. Just about every non-handheld device in my house is hardwired except sonos and Alexas.

MarioM Moderator

29. April 2020 at 15:19 #48660

Hi djvj,

If possible, try connecting the Sonos via Ethernet to test whether the small delays between room 1 and 2 disappear. There are many factors that can cause latency with the Fire Tv Stick though. You could try installing another DLNA app on the stick, since Kodi is no longer officially supported by the Fire TV. Which file formats do you transfer via DLNA? Do the latencies only occur with certain formats?
djvj premium

2. Mai 2020 at 0:48 #48682

Ok so tested Sonos on ethernet and the desyncing happens far less than via wifi. What was about 4 of 5 songs not in sync before, is now more like 1 of 2. Tested starting/stopping 20 songs. Sometimes Sonos is slightly ahead, others its slightly behind. There really is no pattern to it.

My network consists of gigabit switch over cat6, and network is not busy with much.

During the testing, I’ve noticed songs will randomly start desynced, but if I pause and resume, I can often get it in sync. One song I tried 3 times pause/resume and there was different amounts of delay between the 2 zones. I then fast forwarded and they went perfectly synced for the remaining of the song.

I’m not sure what the culprit would be, but it seems like it would be more how each device handles DLNA streams. I’m planning on getting another Pi and eventually for another zone, but don’t have 2 of the same hardware to test yet.

About the Firestick, what’s another app that’s suggested to use? Plex?

I use mp3 at the moment, mostly vbr. I can try to find some flacs if you think that would make a difference.
- This reply was modified 4 years, 6 months ago by djvj.
MarioM Moderator

5. Mai 2020 at 14:41 #48698

Hi djvj,

You could try Plex, but it probably won’t help much. It looks like the Fire TV Stick is generally not really suitable as a multiroom audio player, since it does not support protocols supported by the Squeezebox Server officially. All solutions to integrate it require third party applications or other workarounds where it is impossible to say which processes are running in the background that may delay playback.
I can only recommend you to test another Pi running Squeezelite in your multiroom setup and see if it can be properly synchronized with the rest.

Mark-in-Seattle_GMT8 premium

12. Mai 2020 at 9:55 #48756

Sorry to discover you are battling multi-room audio sync issues. This issue is very annoying and difficult to remove.

In my experience multi-speaker, multi-amplifier syncing works very well using Squeezebox server (LMS) and squeezebox clients. The older original Squeezebox receivers in our house (3 units) and squeezelite running on a Raspberry-Pi3b with a HiFiBerry Amp2 stacked on top, can play songs from the LMS server all day staying perfectly in sync. It is amazing technology, to stay in sync, which I did not appreciate until I tried other music server and receiver options: DLNA digital speakers and others which drifted in an out of sync as unfortunately you are describing. Our LMS server is hosted by the same Raspberry-Pi3b mated to the HiFiBerry Amp2. The max2play OS runs squeezelite locally directing audio output thru the HiFiBerry Amp2. My Squeezeboxes are on ethernet, but thru multiple switches. For a while one was connected to the LMS via WiFi. Didn’t matter, they all stayed in sync regardless of digital transmission paths.

When experimenting with (6) Insignia brand, model# CSPGASP2 DLNA digital speakers (WiFi links only) I believe the fault of not staying in sync for them was due to poor design of the server software and not the technology in the speakers themselves (a german company I believe designed the WiFi speakers). These speakers had chips with „stay-in-sync-reference-timing-clocks“ built in the speaker electronics. Some music server software knows how to use this shared reference clock technology to sync the speakers and other servers do not. Squeezebox server (LMS) seems to enable it’s own receivers to use a shared reference timing clock, so the audio always stays synced.

My point in mentioning this is to suggest keeping multi-room speakers „in-sync“ is not an accident due to the absence of transmission delay, variable path effects …etc. In-sync audio across multiple digital delivery paths is a deliberate and specific function enabled by the architecture of the music server software communicating and re-characterizing, during playback, the amount of delay injected to each receiver channel to KEEP everything in sync for our benefit. This is active control by the server utilizing feedback from the receiver/speakers. Perhaps some receivers also utilize electronic circuitry built into the receiver/amplifiers that make accepting synchronization control instructions from different server software possible, not just one proprietary version (LMS, Sonos) … don’t know for sure.

I do know Squeezebox receivers have this built-in. Change the signal path, they still stay in sync. The Insignia speakers also have a „stay-in-sync-reference-clock“ design, but the truly awful Google Home app that must be used to initially configure Insignia speakers could not broadcast an audio stream to keep them all in sync. However, under the right conditions, in certain modes, I could get my Squeezebox server (LMS) with a DLNA plugin to use „stay-in-sync-ref-signal“ with the Insignia speakers and all (6) stayed in sync throughout our house. That was very nice.

Just suggestions as to how to approach the issue. Hope it helps your experiments ultimately be successful.