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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M

MJW75

Enthusiast I

Nice one. It is good that you could replicate this.

So whatever the Beam is sending to the TV to cause the drop outs is something that would go down the optical part. I guess that could narrow it down, but I’d guess Sonos already knows what the issue is. Either way, if this workaround works for the long haul, it is good enough for me.

R

RANDUSR23296

Enthusiast I

Nice one. It is good that you could replicate this.

So whatever the Beam is sending to the TV to cause the drop outs is something that would go down the optical part. I guess that could narrow it down, but I’d guess Sonos already knows what the issue is. Either way, if this workaround works for the long haul, it is good enough for me.

I re-wired my sacrificial Amazon Basics “HDMI with ethernet cable”. Pins 1-12 (3xTMDS data and TMDS clock) are now “open circuit” and pins 13-19 (HEAC/eARC, DDC, HP, 5V) and shield are connected (I finally found my HDMI cable tester as per photo). Behaves the same as the reversed optical cable which means that the active components (e.g. I2C buffers) inside the optical cable can be eliminated from contributing to the workaround.

My guess is that the TV is losing TMDS clock sync, although there is apparently some control data sent over the TMDS lines too. Either way, you’ve isolated the issue even further, and not only, as you say, should Sonos know the cause already, they could have offered a workaround months ago by defeating their TMDS signal (it’s still not enough evidence to attribute an actual bug to either/both the TV/Beam2).

So, @Corry P - feature request please: a switch to disable the B-roll video stream on the Beam 2 until a full fix is implemented. It’s not like it does anything useful anyway, a “now playing” screen would have been much better use of the video output.

Corry P

Sonos Staff

Hi @RANDUSR23296

I’m not sure a feature would be added to mitigate an issue that we’re not yet sure is for us to resolve, but that’s not for me to decide. To make a request, however, you’ll need to start a new topic thread with the request in it - please feel free to do so.

"Common sense is the collection of prejudices acquired by age eighteen." - Albert Einstein

S

ste_ms

Enthusiast I

Looks like no fix in 15.2, disappointing as I hoped this would be the one.

R

RANDUSR23296

Enthusiast I

Looks like no fix in 15.2, disappointing as I hoped this would be the one.

After 8 months, Sonos still don't know if it's even their bug...

M

MJW75

Enthusiast I

Looks like no fix in 15.2, disappointing as I hoped this would be the one.

That is disappointing. At least my workaround is still working (see my previous posts if you haven’t already), so I’m happy enough that it will no longer cause me issues. I’ll still follow this for a proper fix though.

For anyone interested, this is a the cable I’m using which fixed the problem for me.
https://www.amazon.co.uk/dp/B09YPR5SD4

O

OmriP

Lyricist III

Looks like no fix in 15.2, disappointing as I hoped this would be the one.

That is disappointing. At least my workaround is still working (see my previous posts if you haven’t already), so I’m happy enough that it will no longer cause me issues. I’ll still follow this for a proper fix though.

For anyone interested, this is a the cable I’m using which fixed the problem for me.
https://www.amazon.co.uk/dp/B09YPR5SD4

Dang unfortunately they don’t ship to Israel or it’s all out of stock, but Amazon says currently unavailable :(

R

RANDUSR23296

Enthusiast I

Looks like no fix in 15.2, disappointing as I hoped this would be the one.

That is disappointing. At least my workaround is still working (see my previous posts if you have t already), so I’m happy enough that it will no longer cause me issues. I’ll still follow this for a proper fix though.

For anyone interested, this is a the cable I’m using which fixed the problem for me.

Arguably, there's even less chance of seeing a change in the Beam 2 now there's a relatively cheap external workaround identified.

However, how does your reversed optical perform with Atmos streams? Mine keeps dropping them so I won't recommend my optical cable as a workaround. I may make up a more robust TMDS-less cable and see how that behaves on DD/MAT

M

MJW75

Enthusiast I

Looks like no fix in 15.2, disappointing as I hoped this would be the one.

That is disappointing. At least my workaround is still working (see my previous posts if you have t already), so I’m happy enough that it will no longer cause me issues. I’ll still follow this for a proper fix though.

For anyone interested, this is a the cable I’m using which fixed the problem for me.

Arguably, there's even less chance of seeing a change in the Beam 2 now there's a relatively cheap external workaround identified.

However, how does your reversed optical perform with Atmos streams? Mine keeps dropping them so I won't recommend my optical cable as a workaround. I may make up a more robust TMDS-less cable and see how that behaves on DD/MAT

No issue with Atmos here, although one time audio just disappeared completely but I’m pretty sure the Apple TV just crashed (restart sorted it).

Y

yofalat611

Enthusiast I

Looks like no fix in 15.2, disappointing as I hoped this would be the one.

After 8 months, Sonos still don't know if it's even their bug...

Would be one thing if they can confidently proclaim it isn’t theirs. But to still be clueless after almost 9 months? Bravo. I’m not expecting anything from Sonos anymore. Just biding my time until the next upgrade.

Anyway HDMI1 still works for me and I turn off my power strip 2-3 times a week. I’ve only skimmed recent posts -- does a way one cable disable/downgrade HDMI-CEC? I’ve actually ran out of ports so I use an HDMI switcher on HDMI1 where I connect all devices that regularly use PCM 5.1. I guess that’s another option people may consider.

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