Contributor I

Lost surround and sub ( after update ?)

Forum|Forum|4 years ago
April 23, 2022
1604 replies
81295 views

Hi

I don’t know if my issue is related to the 14.6 update but I noticed today that I had no sound from my surround (play 3) and my sub (Gen 2), only the Arc is working They are still present in the app under the my System view but now sound which every sources

When I reboot each of them, the sound comes back temporary, but when I switch to another source or audio format, thé Sound disappears again. Tried several times, same behavior

Thanks for your help

This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

Show previous replies

F

Freddy45764

Enthusiast II

@Freddy45764 i agree I suspect it’s something to do with Dolby Mat. I actually kinda don’t mind forcing Dolby digital for everything now as I don’t care for the lower volume of LPCM. It’s just annoying to have to manually enable Atmos when I need it

@peterbault - How have you done the ‘forcing’?

Did you do this on AppleTV (i.e. Change Audio) or the TV (i.e. turn off Atmos, disable e-arc)?

I have noticed in the S2 App (and maybe related to what @Freddy45764 is saying) that when I am testing I either have Dolby Atmos come up or (when playing 5.1) it comes up as Multichannel PCM or something.

Multichannel PCM x.x would be your Apple TV using Dolby mat to decode on board and send multichannel PCM stream. Atmos is a bit more complicated. When Sonos reports atmos, you’re getting one of Dolby digital +, TrueHD, or multichannel PCM with Atmos metadata attached. I haven’t found a way to tell which it is from within the S2 app.

F

Freddy45764

Enthusiast II

It’s rather a strange HT issue, isn’t it? I can perhaps see why this might take a little while to resolve, as there is no clear, obvious pattern, or way, to easily reproduce the issue across all our different system setups.

Except that I’m 1000% sure I’ve solved it every time I have a new whacky idea until I’m proven wrong 15 minutes later

S

sparkymark75

Enthusiast I

Here’s my latest theory:

Based on my observations, I get extended periods of stability until something ‘triggers’ the issue and then every switching activity (source, codec, app, content, etc.) brings a high likelihood of dropout. Then I do a big reboot/reset/rebuild by hard rebooting, disconnecting, unpairing/repairing and then I’m stable again for a while.

Looking for commonalities in this thread, everyone experiencing this issue has an Apple TV 4K or Nvidia Shield and a newer high end TV that should support eARC. Although the issue occurs across more source devices, those things seem present for everyone. Apple TV 4K and Nvidia shield have Dolby Mat encoders/ decoders. They handle Dolby content by decoding on-device and sending a multichannel PCM stream rather than native Dolby bitstream unless you somehow force them down to Dolby Digital (not plus) witch is then bitstreamed. eARC support is required in the tv for multichannel PCM or else the Apple TV automatically downgrades to bitstreamed Dolby digital. It’s also a pretty specific combination of devices required to get multichannel PCM to the Sonos ARC which might explain why only some people are experiencing this. It also explains why some users have reported improvement or fully masking the issue by disabling eARC or forcing the Apple TV to Dolby digital (not plus) which would result in bitstream. I therefore think the ‘trigger’ is related to Dolby Mat/multichannel PCM. Once triggered, then you see the dropouts everywhere until you rebuild your system.

I’m going to try my most extensive rebuild yet and leave all sources disconnected and use the native tv apps which should give me bitstreamed Dolby digital + and atmos. If that’s stable, I’ll connect my Blu ray player and try bitstreamed TrueHD. If that’s stable I’ll connect my Apple TV’s and see if the issue reoccurs

The issue occurs for me using solely the apps in my Samsung TV. I don’t use an Apple TV. The only external device I use occasionally is a PC connected to the TV.

I’m wondering if it’s an eARC/HDMI related issue.

F

Freddy45764

Enthusiast II

The issue occurs for me using solely the apps in my Samsung TV. I don’t use an Apple TV. The only external device I use occasionally is a PC connected to the TV.

I’m wondering if it’s an eARC/HDMI related issue.

Windows does Dolby mat if I’m not mistaken but maybe this is the first dent in my theory. I’d really love to hear from someone who uses exclusively a Roku or something

peterbault

Enthusiast II

the system where I don’t have the issue the only device I have that uses Dolby Mat is Xbox series x I think? It’s in Dolby Atmos 100% of the time though so maybe that’s why it hasn’t caused the issue?

F

Freddy45764

Enthusiast II

the system where I don’t have the issue the only device I have that uses Dolby Mat is Xbox series x I think? It’s in Dolby Atmos 100% of the time though so maybe that’s why it hasn’t caused the issue?

Ya I was thinking about your system with your Xbox. Wasn’t really sure how that device worked or if you use streaming service apps or just game on it. Interesting to hear it’s 100% atmos

peterbault

Enthusiast II

the system where I don’t have the issue the only device I have that uses Dolby Mat is Xbox series x I think? It’s in Dolby Atmos 100% of the time though so maybe that’s why it hasn’t caused the issue?

Ya I was thinking about your system with your Xbox. Wasn’t really sure how that device worked or if you use streaming service apps or just game on it. Interesting to hear it’s 100% atmos

Yeah all I do is game on it and you just set it to bitstream Dolby Atmos and it upmixes everything. Any content watching I use the tv apps

peterbault

Enthusiast II

I have many Apple TV’s in the house I could hook one up to my LG CX system and see if it reproduces the issue. I don’t really feel like power cycling anything in my office though haha

F

Freddy45764

Enthusiast II

I have many Apple TV’s in the house I could hook one up to my LG CX system and see if it reproduces the issue. I don’t really feel like power cycling anything in my office though haha

Don’t do it!!! Don’t invite more pain on yourself

mejustowen

Trending Lyricist I

does anyone experiencing the issue have an LG OLED? My system that doesn’t have the issue is a LG CX but my system that does have the issue is a Sony A9G

Yeah I have an LG OLED BX which is the step down model to your CX and I am also experiencing the issue. I tried a lot of things but I gave up and have temporarily removed the sub and surrounds and i’m just using the Arc solo.

Show more replies

Sign up

Login to the community