Trending Lyricist I

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.

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Pinned Reply By Corry P

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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RANDUSR23296

Enthusiast I

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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RANDUSR23296

Enthusiast I

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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OmriP

Lyricist III

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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RANDUSR23296

Enthusiast I

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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RANDUSR23296

Enthusiast I

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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OmriP

Lyricist III

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.

Had several power outages for a few consecutive days and now the problem has returned after being gone for about a month.

This is so frustrating, and neither Sonos nor LG seem to care.

I’m on LG G2, so it’s definitely not limited to the C1.

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ste_ms

Enthusiast I

Back again for me, this is becoming a complete deal breaker now.

Please, please Sonos can we get some kind of acknowledgement of this @Corry P, it’s been near the top of these forums for 6 months now with a wide variety of users reporting the exact same problem on the same hardware - surely an easy one to replicate?

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OmriP

Lyricist III

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.

Had several power outages for a few consecutive days and now the problem has returned after being gone for about a month.

This is so frustrating, and neither Sonos nor LG seem to care.

I’m on LG G2, so it’s definitely not limited to the C1.

Ok so twice more I have been able to make it go away. I don’t know how but it definitely involves turning QuickStart+ on then turn off the tv, wait a few minutes, turn on tv wait a while, turn off QuickStart+ then start playing randomly with every setting related to sound (simplink, passthrough to pcm or auto, bitstream to pcm, turn on and off eARC repeatedly etc). Then turn off tv, wait a while, turn it back on and leave it on some screen playing music (for example Home Screen of ps5). Then this error just goes away after a while and doesn’t return unless there’s another power outage. I know it sounds like total voodoo and hand waving but it already worked 3 times for me. I’m even wondering if my actions actually have any effect or it’s simply time passing that fixes it but anyway that’s all I have for you so take it for what it is and I hope it helps. The method is a bit random but the results are consistent and stay fixed.

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RANDUSR23296

Enthusiast I

Seems odd that power cycling the Beam reverts to the dropouts, but does power cycling the TV? Is there some sort of HDMI negotiation that happens only when the Beam powers up versus pulling the HDMI cable?

It’s also odd that I can hot swap another eARC device but only the Beam has the dropouts, as if the the buggy state is in the Beam, or the LG is remembering devices that have previously negotiated on power up (or the two devices are just using somehow different flavours of PCM 5.1 on the wire, hard to tell just by trusting the status labels of the vendor’s apps).

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Eruvatar

Contributor I

I just noticed that there is a new firmware for LG C1 and a new Sonos update, I won’t be home for a while so I can’t test, did it solve the dropouts by any chance ?

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