Multichannel PCM 5.1 dropping out since 14.10 update


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Anyone else experiencing the same issue? Multichannel PCM 5.1 blanks out for a second every 1-2 minutes. I don’t think it’s a bandwidth issue as it works flawlessly with Multichannel PCM 7.1 (thorough test) and Dolby TrueHD Atmos (quick test). And it may have been caused by the Sonos 14.10 update. Setup is PS5→ LG C1→ Beam 2 (via earc).

 

2 weeks ago before the 14.10 update, I watched a bluray film wherein I had my PS5 transcode the DTS-HD MA 5.1 audio to Multichannel PCM 5.1 (as the C1 does not support DTS) and had no issues. Earlier today, I played a bluray film for the first time in 2 weeks and I encountered consistent audio dropouts every 1-2 minutes. It had the same setup where DTS-HD MA 5.1 → Multichannel PCM 5.1. I tested other bluray discs including the one I watched 2 weeks ago and they all now have the same issue.

 

Curiously, I’ve been gaming heavily on my PS5 the past two 2 weeks and haven’t had any audio issues. Then I realized that I’ve been using Multichannel PCM 7.1 when gaming on my PS5. So I made some changes under the PS5 sound settings to make it output Multichannel PCM 5.1 instead. Lo and behold, I am now getting the same consistent dropouts in games and even on the PS5 main menu.

 

I think it’s due to the Sonos 14.10 update as that’s the only firmware update I’ve done in the last 2 weeks. No PS5 update, no LG C1 update. Well actually while I was composing this post, I received and applied the latest LG C1 firmware update and I still have the same issue.

Corry P 8 months ago

Hi @throwawaybeam2 et al

We now recommend you reach out to the TV manufacturer (LG) as this behaviour is also occurring with different soundbar manufacturers (so it’s not a Sonos-specific issue).

Alternatively, please utilize different audio formats from McLPCM 5.1 (e.g., McLPCM 7.1, DD+, etc).

I hope this helps.

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Sounds like it’s an issue in the TV set somewhere. Sonos plays whatever it’s handed. 

Couldn't possibly be a Sonos bug, right? Despite the Beam 2 having internal audio buffers for lip sync, true play, multi-room, and having CEC control and HDMI handshakes and considerable DSP. Could be in the C1 too from the experiences posted, but let’s try to remain objective and keep the apologist rhetoric to the first page of these threads?

Edit: That being said I noticed there is a new LG C1 firmware released (03.33.26) which I have yet to install, will report back if this changes the behaviour of the dropouts

Did the firmware update fix the issue ? I am having the same issue with an LG C1 but it looks like your region got that update I am on the US and we are still on .11

03.33.26 seems to have gone missing. It installed on my A1, but not on my C1. There’s a reference to it on reddit about a month ago, but not much discussion. So unfortunately, I’ve no further observations to add yet. 

I made an incorrect assumption (unrelated to Sonos). I just checked on the UK LG support site, looks like A1 and C1 are on different firmware branches. The A1 shares a branch with the B1 OLED, but also the NANO models, which surprised me. So who knows when (or even if) 03.33.26 will arrive for the C1, and that’s despite both TV sets spamming me with the “We kindly inform you that LG Smart TV is scheduled to be updated...” messages on power up.

Beam 2 + LG G2 + PS5. Exact same issue with the audio dropping every few seconds, only when PS5 is set to AV Amplifier 5.1 LPCM.

After so many people here complained on the exact same issue I really don’t understand why Sonos is having such a hard time replicating it. All it takes is an LG TV and a Beam 2 with some 5.1 LPCM track.

This wasn’t an issue with my LG C9 btw. Seems like Sonos doesn’t like LG and LG doesn’t like Sonos back.

Ok so, it seems like, hopefully, I managed to fix the problem. I disabled “QuickStart+” in the TV menu, played around back and forth with some of the audio settings for a few minutes (bitstream->pcm and back, passthrough->auto and back, eARC on and off etc. multiple times) then set my PS5 to AV amplifier mode with 5.1 channels and while leaving it on and browsing the web for more info on the problem I noticed that there are no more drops in the sound (the PS5 was on the sound menu for some 15 minutes while it was idle). I found it odd so I went ahead and played a game for several hours, making sure it’s on 5.1 channels mode with LPCM, and there were no more sound drops. I then also noticed that I was not using the Sonos hdmi cable provided with the soundbar but some generic hdmi cable (because the Sonos one was too short). I went ahead and tried replacing it with the Sonos cable just for good measure as I’ve read it’s higher quality. Since then several days have passed and I’ve had no more drops. I don’t know if QuickStart+ was the culprit, or fiddling around with the settings helped, or perhaps it was even the cable, so I know it sounds a little bit like voodoo, but all of these steps together fixed the problem for me, at least so far.

Might be worth a shot for you guys too! Let me know if it helped anyone.

This this!! Thank you! I turned off QuckiStart+ and no more drop out is pcm 5.1 I tested the apple tv nintendo switch and PS5 multiple hours with games movies and tv shows

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Beam 2 + LG G2 + PS5. Exact same issue with the audio dropping every few seconds, only when PS5 is set to AV Amplifier 5.1 LPCM.

After so many people here complained on the exact same issue I really don’t understand why Sonos is having such a hard time replicating it. All it takes is an LG TV and a Beam 2 with some 5.1 LPCM track.

This wasn’t an issue with my LG C9 btw. Seems like Sonos doesn’t like LG and LG doesn’t like Sonos back.

Ok so, it seems like, hopefully, I managed to fix the problem. I disabled “QuickStart+” in the TV menu, played around back and forth with some of the audio settings for a few minutes (bitstream->pcm and back, passthrough->auto and back, eARC on and off etc. multiple times) then set my PS5 to AV amplifier mode with 5.1 channels and while leaving it on and browsing the web for more info on the problem I noticed that there are no more drops in the sound (the PS5 was on the sound menu for some 15 minutes while it was idle). I found it odd so I went ahead and played a game for several hours, making sure it’s on 5.1 channels mode with LPCM, and there were no more sound drops. I then also noticed that I was not using the Sonos hdmi cable provided with the soundbar but some generic hdmi cable (because the Sonos one was too short). I went ahead and tried replacing it with the Sonos cable just for good measure as I’ve read it’s higher quality. Since then several days have passed and I’ve had no more drops. I don’t know if QuickStart+ was the culprit, or fiddling around with the settings helped, or perhaps it was even the cable, so I know it sounds a little bit like voodoo, but all of these steps together fixed the problem for me, at least so far.

Might be worth a shot for you guys too! Let me know if it helped anyone.

This this!! Thank you! I turned off QuckiStart+ and no more drop out is pcm 5.1 I tested the apple tv nintendo switch and PS5 multiple hours with games movies and tv shows

I had to look up what QuickStart+ even was, but I can see how this might be cause, possible apps running in the background trying to take control of the audio output stream at regular intervals, but they only understand 5.1, so don’t impact an HDMI 7.1 stream? Reboots/setting changes may force some background apps to stop, and exhibiting different behaviour?

https://www.reddit.com/r/LGOLED/comments/s3v03d/guys_turn_off_quick_start_on_your_lg_oleds_if_you/

Also, if owners are switching off QS+ for other reasons, might explain the reduced number of reports of this problem.

However, I just checked and my QS+ was already disabled even though I hear the dropouts...

I'm also having this issue with the Sonos Beam Gen 2 and the LG C1. I had already disabled QuickStart+ and turn off the TV has not helped.

 

Is it the consensus that this is an LG bug? Is there any point contacting their support?

So after 3-4 days the issue returned after turning off QuckiStart+ LG recently started the roll out of a new update it is available on a few countries but no in the US 

I will download it manually through the LG Korea website and install it manually via USB and see if it is finally fixed 

@Ariel47 

 

Let us know if that works.

 

Downloaded new update from Korea LG website and updated it from USB. For the moment, it seems the problem is finally solved!! Will see how it goes the upcoming days… Fingers crossed!

Has anyone else tried the new firmware to resolve this issue?

After a movie and an hour of switch gaming no drop outs so far with the new firmware 

Awesome. I'll try it myself today. 

I applied the update and I still have the issue. I think I read somewhere that HDMI-CEC might be broken. I'm going to try restarting everything and see if that helps. I can't disable CEC on the TV while the Beam is plugged in.

After two days the issue returned unfortunately

I am losing my mind trying to fix this. Been going on for so long. it suddenly starts working for a period and then restarts again. Beam 2, One, and Sub 3 with LG CX

I feel like we can't narrow down what hardware is causing this issue. It could be Sonos or LG.

Does anyone have an eArc soundbar from another manufacturer they could test with 5.1 pcm?

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Beam 2, One, and Sub 3 with LG CX

I feel like we can't narrow down what hardware is causing this issue. It could be Sonos or LG.

If I remember the posts on this thread correctly, on the Sonos side it seems limited to Beam 2 reporting issues with the C1, and now CX. Several users have reported no issues with the Sonos Arc (it’s a frustrating name to search amongst ARC, eARC and Arcana...).

Does anyone have an eArc soundbar from another manufacturer they could test with 5.1 pcm?

I may be able to run a brief test on an eARC enabled AVR soon, although if I don’t hear the dropouts that won’t prove much.

Was troubleshooting with chat for the last hour or so. We got to this, “We can see clearly where the initial audio format, that should be fine, changes to something unsupported, causing the audio issue to start, since we cannot decode the forma.”

Chat support not able to troubleshoot further said I would need to talk to phone support, so I guess I will try that when they are open.

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I wanted to wait until the new firmware arrived for the CX but it hasn’t fixed this issue, surely Sonos can look further into this and respond here in the forums? 

Annoyingly… The fault has stopped again so I can’t call them right now. Just waiting for it to break again. 🙄

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Annoyingly… The fault has stopped again so I can’t call them right now. Just waiting for it to break again. 🙄

Same here, so I’m now holding off upgrading the LG firmware and wiring in the eArc amplifier until it returns.

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If you want the issue to reappear again try unplugging and plugging again the beam2/arc from the mains. I have done this for the night multiple times when there was no issue only to find it had returned following morning.

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If you want the issue to reappear again try unplugging and plugging again the beam2/arc from the mains. I have done this for the night multiple times when there was no issue only to find it had returned following morning.

Quick power cycle and the drop outs returned immediately. I think I’ll keep the LG firmware on 03.33.11 until I’ve tried the other eArc device over the weekend.

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I’ve managed to get the system into a state where hot swapping the EARC HDMI cable between Beam 2 and eARC AVR results in the dropouts remaining on the Beam 2 and none on the AVR. AVR confirms that it’s receiving 5.1 channel PCM at 96KHz. 

In an earlier test the Beam2 played without dropouts after swapping back from the AVR, they returned after a mains power cycle. I’ve power cycled the AVR in the same way but no dropouts after power up

I think this means I can only narrow down to one (or more) of the following:

  • There is a bug in Beam 2
  • The Beam 2 is behaving correctly but negotiates the C1 into a glitch state which some other eARC products do not.

These have been brief tests though. I plan to watch some DTS blurays on the C1/AVR over the weekend for soak testing before returning it to its own system (actually prefer the Sonos sound in this room at the moment although I put no effort into setting up the AVR just found any old front speakers and no room correction).

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For me the problem has not returned since I solved it by turning off that LG feature I previously mentioned, even with multiple power cycles. But I’m not using an AVR.

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I’ve managed to get the system into a state where hot swapping the EARC HDMI cable between Beam 2 and eARC AVR results in the dropouts remaining on the Beam 2 and none on the AVR. AVR confirms that it’s receiving 5.1 channel PCM at 96KHz

Could be an invalid test though, maybe the Sonos is receiving 48KHz.

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I’ve managed to get the system into a state where hot swapping the EARC HDMI cable between Beam 2 and eARC AVR results in the dropouts remaining on the Beam 2 and none on the AVR. AVR confirms that it’s receiving 5.1 channel PCM at 96KHz

Could be an invalid test though, maybe the Sonos is receiving 48KHz.

I’ve repeated the tests with 5.1 PCM @ 48kHz, same outcome. Dropouts repeatable on Beam 2, no dropouts on AVR. I’m confident the issue is limited to the Beam 2 and LG OLED combination, but not sure if the Beam is actually mis-behaving or just negotiating a valid, but buggy mode in the TV that other eARC devices do not use.

LG firmware is now 03.34.55 and the dropouts persist.

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