Multichannel PCM 5.1 dropping out since 14.10 update
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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Hi @yofalat611
Thank you for your concern. Yes, I can officially confirm that we, the community team, are making our engineering teams aware of these kinds of topics. Just yesterday I updated the document in which we track all the relevant information from this topic, and made sure the engineering team is aware of it. During the update, I also noted that while there is quite a few users in this topic, there are not nearly as many registered cases, or, their community account is not the same as the account they use for their Sonos system. So again, I can only reiterate that if you’re experiencing this issue, please get in contact with our support team if you haven’t done so already.
When I’m on my ps5 and audio is playing, I turn on my Apple TV (without switching to its source) and the moment it turns on, the audio cuts, just as it does regularly. It returns moments later.
I can repeat this behaviour, as you say it does sound exactly like the regular audio drops. I pulled the power on the ATV a few seconds after the PCM 5.1 dropped on the active HDMI port. There were 3 short audio drops whilst the ATV booted and then the next scheduled dropped occurred at 59 seconds. I’ll try with the A1 next time I have access to the HDMI ports.
Also, I managed to trap the bug into a single HDMI port. Further to observing the PS5 was bugged and the ATV wasn’t, I then repeatedly swapped the HDMI cables between ports 1 and 3 at the TV end. It didn’t matter which device was playing on port 3, it was the bugged one. HDMI 1 also continued without dropouts, regardless if the source device was PS5 or the apple TV. Suggests the C1 isn’t blameless?
C1 firmware updated to 3.34.70, no change in audio drops.
I also sacrificed a “high speed with ethernet” HDMI cable and cut what I think is pin 13 (CEC), but whilst the HDMI 2 video is intact, and I’m now able to de-activate CEC (the remote also stays working), the TV doesn’t engage either eARC or ARC and audio is limited to the TV speaker. I cut the red wire - maybe I should have cut blue
What you’re saying is interesting. For me the ATV is on HDMI 1 and I don’t have sound drops (although it’s usually playing Atmos or stereo content), and the Switch is on HDMI 3 and the PS5 on HDMI 4.
Perhaps it’s HDMI 3 and 4 only which are bugged…
Anyway it’s looking like something with some kind of device polling every 59 seconds.
The problem has always been my ATV on HDMI3, the PS5 on HDMI1 is fine. I had previously moved the ATV to HDMI4 but that never fixed it.
Perhaps the HDMI sockets are split into 2 banks somehow with the Beam being on the HDMI 1 and 2 ‘bank’ due to ARC being HDMI2? Then perhaps it is some kind of interrupt from the 3/4 bank that is causing the issue? I still can’t work out why the Arc would be unaffected though
This is my best guess as well.
It has gotten noticeably worse since the last few updates too.
I am having this same issue and it has been going on for months. This is specifically woth my switch which can only do pcm 5.1.
To further reinforce some other people's notes - this problem only occurs on my switch which is on hdmi 4. Same issue with hdmi 3. But like other people said - hdmi 1 did NOT have this issue when I tried the switch on that. Hdmi 2 is the earc so can't use that one.
What is going on here? I really want to use my surrounds but the constant sound cut off is driving me nuts. My hdmi 1 is for my ps5 and don't want to be limited to one hdmi. This did not always used to happen so it's very frustrating.
Keep this menu displayed when playing 5.1 audio and when an audio drop comes, ‘6CH’ drops to ‘2CH’ momentarily before coming back (I managed to get this on video). Hit the up button on the remote every minute to stop the menu timing out while you do this.
Good spot, this is new behaviour. I’ve recently seen the TV flick between 6ch and 2ch on this menu when I’ve confused it by making too many changes, but it’s the first time I’ve noticed the TV show any reaction at the time of a drop out. In my case it has just flicked between 6ch → 4ch → 6ch during the drop. It didn’t do this when I started looking at this months ago (when I’m certain HDMI 1 was also buggy). Perhaps this indicates LG is looking into this bug after all (or that I just have a bad memory...)
So it is not the sound bar. It is either the source (although no issue on my other TVs) or the TV. I’m guessing TV as why would it work on HDMI 1 if it was the source?.
There’s no issue on my alternative eARC devices either (Marantz in my case or Sonos ARC according to this thread), so that logic doesn’t quite stack up. Whilst the Beam 2 may not turn out to be buggy it isn’t blameless in this issue.
Same issue here. I have the latest Apple TV 4K (3rd Gen), LG C2 and Sonos Beam Gen 2 (all on the I also tried an earlier Apple TV 4K box (2nd Gen) and this bizarrely sends 5.1 audio as 7.1 - so I couldn’t use it to test with.
This is confirmed by a few posts on this thread - could be a h/w revision change between gen 1&2 and 3, or just that some manufacturers have no interest I back porting s/w fixes. I’m guessing Beam 3 won’t trigger this issue, will be interesting to see how C3 behaves (if not solved one way or the other by then).
Contributing factors to the bug seem to be:
Beam 2 reboots
CX-C2 (and G family) TVs
HDMI 3 (and 4?)
TV cache of HDMI devices (disconnecting the Beam 2 and reconnecting doesn’t clear the bug but fiddling with some of the TV audio/CEC settings can do)
So it is not the sound bar. It is either the source (although no issue on my other TVs) or the TV. I’m guessing TV as why would it work on HDMI 1 if it was the source?.
There’s no issue on my alternative eARC devices either (Marantz in my case or Sonos ARC according to this thread), so that logic doesn’t quite stack up. Whilst the Beam 2 may not turn out to be buggy it isn’t blameless in this issue.
Fair enough. My thinking was that the hidden details state HDMI 3 (or 4) drops to 4CH (correction from above, it drops to 4CH not 2CH, but not every time). The TV is set to pass through audio, so it shouldn’t change the number of channels, but I also guess there is some kind of handshake going on with the Beam that could feed back different source requirements, causing the TV to stumble……? Either way, it sounds like exchanging the TV won’t help and everything now seem to work with Apple TV on HDMI 1. The devices on HDMI 3 and 4 don’t seem to output ‘Multistream PCM 5.1’, so that isn’t an issue.
See video below of the audio drop out and the channel number dropping to 4.
but I also guess there is some kind of handshake going on with the Beam that could feed back different source requirements, causing the TV to stumble……?
That’s my guess too. eARC has it’s own handshake: the Beam presents the TV with a Capabilities Data Structure (CDS), independently but similar to how the TV presents the AppleTV (and Beam) with an EDID. The CDS received by the TV on HDMI2 would drive the logic in the TV on what audio sink to present to the Apple TV in the EDID on HDMI3.
Without knowing what the audio stream on HDMI3 looks like during the dropout it’s difficult to know if the AppleTV is involved (maybe an HDFury device can “sniff” this) in dropping the audio. Having read a little about the HDMI port implementations it’s also difficult to know which point the 11111 menu is picking to determine the audio format. Is it really what’s in the TMDS stream, or is it examining a transposed stream on an internal I2S link or ARM bus - in which case the Beam 2 may already have had chance to interfere indirectly via the HDMI3 control registers (via a CDS handshake every 59s) whilst the AppleTV keeps streaming Audio/Video happily to HDMI3 as if everything is stable. We do know that the video stream is not interrupted.
I haven’t yet thought of a way to prove/dismiss the above with any of the equipment I have to hand though. Introducing any kind of passthrough sniffer device may even alter the signalling enough to fix the problem enough so that it can’t be observed :(
I have contacted LG UK (since I just assumed the local LG Israel here will be completely useless in addressing the matter) and after a good 4 days they responded to my email. I will update if I come up with anything useful.
Regardless it feels that we’re homing in on the issue here
Also encouraging that recently more unique posters are finding this thread and describing similar experiences
I’m sure I checked the HDMI status to see if it changed during the dropouts but didn’t see it previously - possibly a tweak in the firmware since then? The app never shows a change from PCM 5.1 when it drops out that I’ve seen.
Sometimes it didn’t do it. It was about 1 in 3 change of showing. In the app, when you start playing something it takes a second or so for the app to show the format. I’m guessing the dropout is so quick that the app doesn’t have time to react.
Update on HDMI 1 - I’ve watched my Apple TV 4K Gen 3 for maybe 6 hours and it seems good so far.
Also - my previous TV was a LG SM9000 which also has eARC. I had no issues with this at all running the same Apple TV 4K Gen 3 and the Beam Gen 2.
I contacted Sonos support so they know there is another user with the same issue.
Same problem here…
LG C2 Beam Gen2, Sub Mini, 2 x One SL HDMI 1: Apple TV (Gen2) HDMI 2: Beam HDMI 3: PS5 (currently set to 7.1., for no dropouts…) HDMI 4: Switch (annoying dropouts… sometimes even NO sound)
My Apple TV is connected with an HDMI CEC Blocker. But i am using mostly the TV Apps. Playing around with connections and power cycles and suddenly it was working. PCM 5.1 was running without issues for about 6-7 weeks.
After a Sonos Update dropouts again… Trying around with power cycles, Ethernet/wifi connections, settings and unplugged HDMI 1. Working again with no dropouts.
Sonos Update yesterday… Dropouts…
HDMI 1 has the same dropouts! Not only HDMI 3/4. In the Sonos App „PCM 5.1.“ is disappearing for very short moment when the dropout accurs.
Only stable but not acceptable „workaround“: don`t use Apple TV, PS5 7.1 Mode, Switch Stereo Mode.
LG C2 and having pcm 5.1 dropouts from PS5 in HDMI 3 and 4. Moved PS5 to HDMI 1 so far no dropouts. Having contacted LG support bout this issue and this forum, I have had LG response:
"I am just getting in contact as our Technical Team has responded on file and have advised that there are no differences in the HDMI ports and so there should not be any reason as to why HDMI 3 and HDMI 4 would be different to HDMI 1. They have advised that we can book this in for a repair as this could be an issue with the HDMI 3 and 4 ports themselves."
So am now booked in for HDMI repair.
Waste of time IMHO, your TV behaves exactly the same as any other LG TV of its model.
It works “as intended”, the problem is that the “as intended” is faulty.
It almost seems to infer that the LG Technical Team are aware of a hardware issue with that TV model. I would have the repair and just see what happens after that.
LG C2 and having pcm 5.1 dropouts from PS5 in HDMI 3 and 4. Moved PS5 to HDMI 1 so far no dropouts. Having contacted LG support bout this issue and this forum, I have had LG response:
"I am just getting in contact as our Technical Team has responded on file and have advised that there are no differences in the HDMI ports and so there should not be any reason as to why HDMI 3 and HDMI 4 would be different to HDMI 1. They have advised that we can book this in for a repair as this could be an issue with the HDMI 3 and 4 ports themselves."
So am now booked in for HDMI repair.
Waste of time IMHO, your TV behaves exactly the same as any other LG TV of its model.
It works “as intended”, the problem is that the “as intended” is faulty.
It almost seems to infer that the LG Technical Team are aware of a hardware issue with that TV model. I would have the repair and just see what happens after that.
It really doesn't, but agreed, if LG are willing to commit some visible effort into trying to isolate this fault then worth pursuing. If they have prepared a h/w HDMI fix for C2, don't fancy the chances of it being back ported to C1/CX.
Will give the LG repair team a chance. As it is strange that the 5.1pcm works fine on hdmi 1 for the last week where in hdmi 3 for the last 3 months I've had to resort to 7.1pcm as the pauses in 5.1pcm have been very annoying. Had the same on hdmi 4 but only tested for a few hours but it was immediately stuttering.
Yeah, I wouldn’t read too much into it either. Probably just a standard response from local LG support. As you are under warranty, they are willing to take a look at your TV. They probably don’t even know that this an issue specific to the Sonos Beam Gen 2 only.
If it’s home service, then you’ve got nothing to lose. But if you have to send the TV to them, I personally wouldn’t bother as it’s a high risk (they could damage the TV), low reward play. In my country, repair is limited to basic diagnostics and part replacement. They don’t tinker. Last resort, they simply replace the TV. And I doubt a simple part/TV replacement would do anything.
Yeah home repair, wouldn't have bothered if it had to go.
@RANDUSR23296 Damn. Sonos should at least send you an Era 300 for all your work lmao. But thanks to you and @OmriP for zeroing in on the HDMI1 thing. If this lasts for me, I could probably hold off on sidegrading now for a real upgrade later.
@RANDUSR23296 Damn. Sonos should at least send you an Era 300 for all your work lmao. But thanks to you and @OmriP for zeroing in on the HDMI1 thing. If this lasts for me, I could probably hold off on sidegrading now for a real upgrade later.
I’d settle for Sonos sending me a human readable log of what events my Beam 2 (in my house, on my network) is seeing on the HDMI eARC pins around the 59s window Realistically, having spent a while on Google, the HDMI spec (1.4 and above) is such a trade secret there’s at least one good reason why that will never happen.
@MJW75 really made a break-though spotting the blips on the 11111 menu. I’ve tried pulling the HDMI plug on a 6ch source on my A1 and it immediately drops to 0Ch, so there’s a difference in how that signal is reported between those chipsets. Maybe the/another bug causes this difference, maybe it’s a recent intentional change from LG to monitor this specific issue. Unfortunately I don’t have a downloaded copy of C1 v03.33.11 firmware to downgrade to find out.
When I run the following commands on Raspbian on a Raspberry Pi3 with Beam2 on eARC:
the 11111 menu displays either 'PCM 6Ch 48000Hz' or 'PCM 8Ch 48000Hz' during streaming and Sonos app also shows the appropriate Multichannel LPCM mode.
When speaker-test is killed, Beam2 goes silent, Sonos app format goes blank immediately, 'cat /proc/asound/card1/pcm0p/sub0/hw_params' shows the RPI’s sound card device is already closed, but:
HDMI1 (not bugged) - 11111 holds the same PCM mode until a different speaker-test format stream is started, up to several minutes later
HDMI3 (bugged) - 11111 holds the same PCM mode, but only until the 59th second after the previous dropout, then 11111 shows the format being pushed to PCM 2.0, where it then stays (again, until a new speaker-test format is streamed)
The above behaviour is the same for 6Ch and 8Ch, the only difference I observed being that if speaker-test is streaming 6Ch during the 59th second on HDMI3, the Beam2 audio (as we know) is interrupted for 1 second. There is a 59 second event for both 5.1 and 7.1, but it is only audible on 5.1.
Replacing the Beam2 with an eARC AVR - when speaker-test is killed on HDMI3 there is no drop down to PCM 2Ch at 59s, both formats remain until a new stream is started. This doesn't give any indication how Beam2 is involved, but only its presence is triggering the TV into doing something every 59s. I couldn't find any obvious HDMI events/errors (CEC, handshakes, etc) on the RPI at the 59s intervals.
A post I found recently observes the dropout period is not tied to the amount of content played (back when it was approximately 40s):
If I unplug the HDMI cable after killing speaker-test, 11111 shows HPD/5V/etc drop low, Video shows 0x0I@0.0Hz, but audio still holds the most recent PCM 6Ch/8Ch value. This is the same on HDMI1 and HDMI3, for the RPI and PS5 as sources. The TV is not reporting the audio format on the input wire. Rather, I guess it’s whatever the mode the next circuit in the audio path was most recently configured to based on the the last frame of audio received. PCM 2.0 is only displayed again when HDMI cable is reconnected. On HDMI3, streaming 5.1/7.1 then resumes the 59s timer.
Bruh Sonos should be paying you for doing their job.
On another note, the sound drops stopped on their own since I installed the last Sonos update and I don’t know if it’s because of the update or because of some unrelated voodoo. I’ve had this problem for weeks now and gave up on fiddling around because it seemed unlike last time this time nothing I did worked, but yesterday it just fixed on its own, and that was the first time I used the TV since the update.
At this point I’m too happy to power cycle the beam and see whether the drops return or not XD
That would give the illusion to a Beam2 owner that it somehow was triggering the problem yet in reality it was still functioning 100% to spec, particularly as eARC devices are still relatively rare and the Beam2 was likely the first eARC device connected up. Testing a different eARC device (for the fewer users who have access) would work fine and look like only the Beam2 was bugged.
Apple TV 4K 2nd Gen and later support eARC so could be used for testing. I may give this a go if I get a chance later today (my HDMI ports are a real pain to access though).
It almost seems to infer that the LG Technical Team are aware of a hardware issue with that TV model. I would have the repair and just see what happens after that.
No don’t try to pawn off the issue to LG lol. It’s a Sonos issue as well, clearly.
To be fair, I did think of a scenario where the Beam 2 is blameless: Maybe the TV has a bug that means the first device eARC device it registers (and it does seem to cache the details of eARC devices) is bugged, but subsequent devices are not (it’s not uncommon for first items in software containers to trigger additional logic or follow modified algorithms that subsequent items added do not).
That would give the illusion to a Beam2 owner that it somehow was triggering the problem yet in reality it was still functioning 100% to spec, particularly as eARC devices are still relatively rare and the Beam2 was likely the first eARC device connected up. Testing a different eARC device (for the fewer users who have access) would work fine and look like only the Beam2 was bugged.
However, if this was the case here, I’d expect to see reports on internet about other devices having dropouts, because they’re the first plugged in, but I couldn’t find any. I could (probably) test this by factory reseting the TV and connecting my AVR as the first eARC, but the lack of evidence on my searches suggests this would not be worth the effort.
Also, that doesn’t prevent Sonos support actively help isolate the issue, and/or even giving some sensible technical engagement (I do appreciate @Corry P’s recent update indicating related activity by the community team).
If this were the case you’d see loads of posts here about people with Sonos Arc, or any other soundbar. The fact that it’s so specific to the beam 2 suggests it isn’t blameless.
Does it stay like this on hdmi 3 / 4 after power cycling? What happens if you change back the cable? And then back again?
I doubt it’s the cable because I’ve tried multiple cables and all had these problems.
Did you try a one way optical HDMI cable?
Leaving the optical HDMI cable installed and the Apple TV on HDMI 3, I power cycled everything. Tested for 30 mins (I know that isn’t long), but no issues. I power cycled everything again leaving everything off for 10 mins. It still worked when it powered back on.
I then power cycled again and changed to the original supplied Sonos HDMI cable between the TV and Beam Gen 2. The issue came back straight away. Power cycled again and the issue is still there.
I just put the optical cable back in and it seems to work again.
I’ll concede that it could be something else, but what I can say is that in my testing it consistently doesn’t work with the regular HDMI cable and consistently does work with the optical HDMI cable. I’ll keep the optical cable plugged in and the Apple TV on HDMI 3 and will update here in a few more days.
If anyone with this issue has a one way optical HDMI cable, please can you try and replicate my findings. Alternatively, they can be bought relatively cheaply on Amazon.
I read somewhere that some features are still bi-directional on optical HDMI but thought I’d try it anyway. I can’t explain why it is working for me and not you. Just to check - you put the cable between the TV and Beam right, with the TV at the source end of the cable? Not between the source and the TV.
I had the source end of the optical cable on the beam, other end in TV HDMI2. So I swapped the ends over (source in TV HDMI2 other into the Beam) and so there was no Sonos video displayed on HDMI2 (as now the cable is in reverse) however eARC was functioning and the dropouts ceased.
...Until I rebooted the beam and there were mini dropouts every 5 seconds. Pulling the optical cable out the beam didn’t clear them, but rebooting the TV did, and the 59s drops didn’t return either.
Reverting eARC to the Sonos provided HDMI cable also reverted the 59s dropouts
I wonder what the minimum set of connected pins is required to make eARC work but not necessarily any other HDMI feature. What might the embedded optical cable transceiver chipsets be telling the TV and/or Sonos when connected in reverse?
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.
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.
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.
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.
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.
CEC still working. The only thing you seem to lose is the Sonos image when selecting HDMI 2 (which is pointless anyway).
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.
Realistically, having spent a while on Google, the HDMI spec (1.4 and above) is such a trade secret there’s at least one good reason why that will never happen.