Sonos Arc loud pop then audio loss

What would really be a good test if you can stand it is watch the same 3 episodes again (or at least put them on and listen for the same audio dropouts). That would have every one of the very same variables in place EXCEPT Trueplay. If there are no audio drops with the exact same signals, this concept of “blame AppleTV” or “blame ATMOS” or “Dolby MAT” etc starts getting more meaningfully undermined. And the confidence that perhaps it is something in the Trueplay algorithm that needs Sonos attention would rise.

Thanks for going to the trouble of at least trying my guess. Hopefully a few more with such issues do too and we begin to see a pattern that could lead to an actual remedy vs. expecting a bunch of other players to do something and/or “don’t use ATMOS” and/or “turn off CEC.” 

Not actually that difficult as I was watching The Good Place on Netflix and each episode is only 20 minutes long. Watched them through again today and no audio drop outs. Fingers crossed you’ve stumbled across something here. We’re also watching Stateless on Netflix which also gives lots of audio dropouts. Will probably watch a couple of episodes tonight so will report back.

Unfortunately I spoke too soon. We had dropouts last night. The weird thing with our Beam is that it keeps dropping the dialogue track but you can still hear the environmental sounds, traffic, birds, rain etc. Sometimes it will drop the dialogue track permanently until you switch Dolby Atmos off.

Arc + surrounds + sub + Apple TV 4K + LG C2 - I’ve had the popping off and on once a month or so, but have the dialogue audio dropouts even more frequently. Most often with Hulu. Super annoying but it never dawned on me that it could be SONOS related as well.

I only made the connection because I couldn’t execute the usual process… which flows right into Trueplay as part of initial setup. In this case, I had to bail on Trueplay until some noise beyond my control was silenced. So I experienced what might be called an audio quality sandwich:

• Great Sonos sound via Arc & twin 300s for a few hours until I could run Trueplay
• Then pop-a-rama from Arc from the same sources that had just sounded fine starting immediately AFTER running trueplay... until I reset to factory
• Then great Sonos sound again because I haven’t re-run Trueplay. A full 8 days in now and all sounds as good as any of us expect from Sonos.

My instincts tell me that is it MORE likely the problem is with Sonos than all this third party redirection. For example, the source never changed here, so the “Dolby MAT” redirection claim should have yielded the same negatives heard in the middle part of the sandwich. It sounded great (perfect?) before & after. Only after running Trueplay was it pop-pop-pop unusable from the very same sources through the very same HDMI cable, with the very same settings set. 

The “don’t use CEC” and “turn off ATMOS” redirect makes no sense either. Else everyone would have the problem vs. only “a small subset” and aren’t both of those just about the point of buying Arc? Why buy an ATMOS soundbar to not use ATMOS? Does anyone want to separately control volume on soundbar instead of using the TV remote?

Blaming AppleTV and Xbox, etc would mean the problem is unsolvable because it seems unlikely those other players will ever modify their audio output to fix this problem affecting “a small number of Sonos users.” 

I have another Arc + Move paired in a room. Both have had Trueplay run several times. No pops at all… but I only use them for music in that room.

The new one paired with twin 300s popped on ALL sources, including Sonos’ own radio channels… and even popped with button presses on the Sonos Arc itself. I’m doubting that Sonos would code their own music and UI sounds wrong to trigger the pops.

So I continue to see the ONE unique variable as having some potential for resolving the “pop” issues described in this thread. Anyone interested in testing, reset to factory, set up again and bail at the Trueplay step. Then see if your reset speaker will pop on anything that made it pop before (same video, same music, whatever caused pops). If you can find a few things that makes it reliably pop every time, test with those same things (same video or audio) after NOT running Trueplay on a reset Arc setup. 

Maybe the audio dropout problem is separate from this? Maybe this is only a discovery for certain pairings of Sonos things like Arc + 300s? Or maybe there’s nothing to this but curious coincidence: sounded fine for a few hours, pop-fest for a few hours- sounded fine for the last 8 days now? For me, all variables are identical except for one: no trueplay run = fantastic sound with no pops in both buns of that sandwich.  

Maybe a simple test can help others too? If a few more will test this and find that it works, Sonos would have something to immediately work on (presumably a bug(s) in Trueplay) to potentially solve this for many with a software update and (fixed) Trueplay re-run. 

Your account seems more repeatable than others that I’ve read. Submit some before and after diagnostics, keep a log and contact Support. They might want to enable a special diagnostic on your system.

Just experienced two pops today for the first time, have had my Arc+One+OneSL for a few years. I thought it was a bird hitting the window until the second one.

The biggest change, recently moved to an LG C3 from a Samsung Q9FN. Since getting the C3 we used the webos apps, but I realized this week a bunch of the LG streaming apps don't offer Atmos but on Xbox they do. Started using Xbox Series X again, got two pops today, both while navigating around.

Definitely had Atmos working on the 2018 Samsung at times (not earc or full hdmi 2.1) so it seems to be some combo of the earc/LG, Xbox, and Sonos for me, and potentially while pressing universal remote buttons to navigate UI.

In my book, it still points to the issue as mainly involving the multi-channel LPCM (container) format where the Atmos metadata is sent alongside the lossless audio stream - so my money is still on the Atmos metadata falling out of sync with the stream and sometimes creating that noise, which you describe as ‘a bird hitting a window’. Maybe it’s devices en-route like the TV and/or cables causing this anomaly too, as clearly it doesn’t happen for everyone and it explains why some users may find solutions when changing a cable or introduce an audio extractor into the path and bypass their TV etc.

I don’t personally use LPCM for Atmos playback, as I don’t have the hardware that supports it and so far I’ve not heard the noise and that’s with an LG TV too, albeit the older C9 TV.

Again, I’ll share that once Trueplay ran and the Pops began, it was not an occasional thing as described just above and Arc would pop whether watching ATMOS or playing Stereo Music (including Sonos own music stations) or even using the buttons on top of Arc and getting audio feedback from presses. 

It’s easy to redirect to “it’s <other parties> fault” but how do we rationalize such speculation against the  experience of NO ATMOS, no Xbox, no AppleTV, etc? Is there any ATMOS at all in Sonos radio stations? Is there any ATMOS in UI audio feedback sounds from touching Arc buttons?

Similarly blaming cables and other devices is fine but in our case we had pop-free audio from ARC for a few hours BEFORE running Trueplay… then pop-FULL audio after Trueplay (no matter what we threw at it)… and then a return to pop-free audio after factory resetting and NOT running Trueplay again. All same sources tested. All same cables. All same settings. If the cause is cable or settings or TV, how can we have pop-FREE periods before and after applying Trueplay (for coming up on 2 weeks now)?

whippleshuttle’s post is interesting in that apparently the only variable that changed was TV type. Apparently, one TV subbed in for another, presumably re-using the same cable and otherwise all of the same stuff, services, settings. If so, that undermines my (wild) assumption that maybe Trueplay has some bugs to address and adds something to the chorus of some kinds of differences in how ATMOS (and DOLBY MAT, etc) are implemented. I’d be interested in knowing if in replacing the TV, did whippleshuttle change any other variable… particularly did they re-run Trueplay? Or use a new cable? Or replace any other supporting hardware at the same time?

Nevertheless, in my experience, where there is a great diversity of possible causes, a good strategy in finding the actual cause is to narrow in on the common elements. What does all such scenarios have in common? That is probably not one cable or one TV or one setting, etc. My gut says scrutinize the common denominator much harder first before then working out into what would seem to be quite diverse- even unique- variables of specific TV, specific cable, specific ancillary hardware, specific services, etc. 

And, of course, there’s always fair possibilities that it is combinations of things that leads to an answer too. If everyone had the POPs, Sonos would have to stop selling the product because the noise and press would sound far louder about the issue. In my case I have a perfectly fine Arc + Move paired on which Trueplay has been run a few times during it’s many years with me- no pops at any time over those years. This other brand new Arc + twin 300s was popping like crazy after Trueplay was run on it. Is Arc + Move somehow immune vs. Arc + twin 300s? Or if I swapped the Arcs and ran Trueplay on the no-pops-ever one now paired with the 300s, would it suddenly start popping? If it was my job to figure this out, I’d try that. But since I now have both setups sounding fantastic, I don’t feel motivation to stir either pot.

Interesting point actually, not a scientific test but the pop did not occur until I switched to Monoprice cables.