Hi @contractcooker,

Welcome to the Sonos community and thanks for bringing this to our attention. Let me share some information to help you out. 

The Sonos Arc can play Dolby Atmos audio. ARC and eARC are protocols responsible for sending audio over an HDMI cable to home theater sound systems like Sonos Arc. Sonos Arc must be connected to HDMI ARC or HDMI eARC to play any Dolby Atmos content. Not all TVs have HDMI ARC or HDMI eARC.The Sonos Beam should be connected to your TV via HDMI ARC, and the HDMI-CEC is enabled. 

Let me suggest the next troubleshooting and see if it works for you.

1. Unplug the HDMI cable from the Sonos Arc/Beam and the TV. 
2. Unplug the power cable from your TV, the Sonos Arc/Beam, and any connected audio source (such as a cable box or video game console). Wait 30 seconds before you plug them back in.
3. Reconnect the HDMI cable directly to your TV and the Sonos Arc/Beam. Inspect the HDMI cable to ensure it’s not bent or kinked and check to see that it’s fully inserted into both devices.
4. Update the TV’s software (if available)
5. Disable eARC on the TV.
6. Adjust the group audio delay - Settings > System > Tap your Sonos Beam > Group Audio Delay and then choose a delay option.
7. Check for Sonos update - Settings > System > Check for updates.

Let us know how you get on with the advice above and run a diagnostic report. Kindly include the confirmation number in your response for us to check. If you have any questions about this. We and the community are always here to help.

Rowena, thank you for the reply.

I followed the steps you outlined and ran a diagnostic report (confirmation number: 1360637274). It appears that this solves the audio dropping out on the Sonos Arc (haven’t had time to test the beam yet) HOWEVER it is my understanding that in order to enjoy the Dolby Atmos features of the Sonos Arc I need to have eARC enabled on the TV. I really want to be able to utilize my sound bar to it’s maximum potential. The Sonos Arc is not inexpensive and Dolby Atmos support was part of the reason why I decided to purchase it. Disabling eARC is not a very satisfying solution for a product that is supposed to utilize eARC. Again, please let me know if my understanding is incorrect but I believe eARC needs to be enabled for Atmos to function.

EDIT: also just wanted to comment that I have used multiple HDMI cables to rule out the HDMI cable being the problem.

Hi @contractcooker, thank you for reaching out to the Sonos community and for letting us know about your concern. We appreciate you for sharing your feedback with us. Disabling the eARC is a workaround to address the audio dropping issues. We have no information to share with you yet when this will be resolved. I would also recommend reaching out to LG for further assistance. Let us know if you need help with any other information, we're here to assist you.

Hi, I was wondering if you can confirm that the vol+ vol- AND mute buttons all work without issue with the LG OLEDCX55, the magic remote  and the Sonos Arc. As I am having issues with the mute button on my Playbase, which apparently cannot be resolved  It seems to be  a firmware issue with the IR controls of the CXTV and/or Magic remote and am not confident about an LG fix ).

(FYI the vol+ and vol- are working, but I cannot get the mute button to work, whatever I try)

Therefore, I  am contemplating  a very expensive, upgrade to make it work, but want to be 100% sure, that the Sonos Arc is fully compatible, with no known issues.

Thanks in advance for your help.

Hi @Gtrex, 

Thank you for reaching out to the Sonos community and for letting us know about your concern. Let me share some information with you.

Instead of infrared (IR), the LG Magic Remote uses radio frequencies (RF) or Bluetooth to communicate directly to the TV. If your Sonos home theater speaker is connected to your TV via optical cable or adapter, some configuration is necessary to enable the remote’s IR output to fully control your home theater speaker, volume up, volume down, and mute buttons. It should also work with Sonos Arc.

Please follow the steps below to configure your LG Magic Remote to work with Sonos home theater speakers:

1. On the Magic Remote, press the Home button and then select Device Connector.
2. Select Soundbar and then the TV port you used to connect the Soundbar, Optical in this case.
3. Select any manufacturer. Although you may see an option for Sonos in this list, we find that Philips seems to work best.
4. Select Remote Type 1 and click Next.
5. Select Done.

Note: If you’re still not able to control your home theater speaker with the LG Magic Remote, try disabling SIMPLINK for the Optical connection under Settings > Sound > Sound Out. Also, check for your LG TV software if up to date.

SIMPLINK is a feature that enables you to control and manage various multimedia devices conveniently using the TV remote.

Let us know if it works. If you need help with any other information, please be sure to let us know.

Hi, thanks for the response. I have tried every solution out on the web for over a week and fully understand why and how some solutions work and some dont, but cannot get the mute button working WHILE THE TV IS ON. And I don't believe any one can with an optical sonos connection. If off it works fine, so this proves the issue is that the magic IR logic although working for + and - is not behaving the same for the mute option. 

FyI the device connector option is not available on the 2020 cx and you need to go through the universal remote configuration and you can select sonos not phillips. (The Phillips options makes no difference to me..I have tried them all).

This remote configuration process somehow tells the cx tv to override the RF for the optical soundbar and send out IR signals for volume. However, this only works for + and - and the LG magic remote is omitting the signals for mute or sending the wrong ones, hence why I strongly believe it is a cx firmware issue.

My question about the arc is basically whether the volume is being. COntrolled BY Yhe hdmi connection on the port (or direct to the sonos VIA THE CABLE)  to avoid me worrying about IR signals.

THANKS 

It is frustrating as I have a £600 soundboard + subwoofer and a pair of sonos 1 rear speakers and a £1300 tv ..a 3 grand system and the volume controls don't work properly :(

(I have also bought hdmi/optical converters and new hdmi cable to try  different configuration, but cannot get it to work)

Now decided, to live with it and let it go....fingers crossed for an LG fix 

1st world problems ......   ;)

After emailing LG and chatting to support, several times over the last couple of weeks and with a final attempt with an email to their official CEO feedback forum yesterday...this lunchtime I had a TV update and my Mute button works... :)

Coincidence? Possibly? Probably,  but you know what, I am going to choose otherwise, and assume it is LG responding quickly and efficiently, well done LG.

My Magic controller with my LG OLED 55CX now controls my optical connected Sonos Playbase perfectly... including the mute option. :)

​Hi @Gtrex, thanks for your response and updating us. I'm glad that you can now control the volume and use the mute option after updating your LG TV.  In most cases, when a function doesn't work, it will be fixed by updating the software. Please let me know if you have any other questions or concerns. We would also appreciate it if you can keep us posted on this. 

Hello

I have the same dropping sound problem with a beam + sonos one’s / TV OLED LG CX configuration.

I think the problem is coming from another TV box that is connected on the TV. Whenever I turn off the TV after sometime I have to reconnect the sonos system to the TV which is annoying.

Any update on how we can fix the problem?

Thanks for your help.

Hi @JM L., thanks for reaching out to the Sonos community and letting us know about your concern. May I ask, have you performed the steps we provided in this thread? If after doing all the steps and the issue is not resolved, it would be best to contact our support team for more in-depth troubleshooting steps. Please do not hesitate to reach out if you have further questions or concerns. We are always happy to help out.

Hello, I am having the same issue- Sonos ARC with LG 65oledCX. Original cable seems to work fine, but either lg or sonos is dropping hdmi arc connection by using different hdmi cable. I got plenty of hdmi 2.1 cables and somehow they aint working. I was wondering if sonos is restricting usage of other cables...

Following an incident involving a friend's toddler and his toys, my 4k TV now features a bright white illuminated crack across the screen.

As such I am currently in the market for a new TV and I want to make sure its fully compatible with my Arc and the rest of my Sonos array. 

The LG CX series seems to be the most likely contender based on price and features.

Can anyone confirm whether these TVs now have Atmos pass-through? (I have a HD Fury Arcana but prefer to not need it).

@DuranDoranMartell The LG CX is equipped with HDMI eARC and supports Dolby Atmos pass through.

@contractcooker - did you find a solution to your issue? I have an LG CX with the Arc and also noticed a signal drop from time to time. It’s a minor annoyance and switching off eARC isn’t really a workaround as you lose Atmos and the Arc doesn’t have any extra HDMI inputs for me to plug devices into directly.

What I did find was either a quick tv reboot or switching the audio source to internal then back to Arc solved it for me. I’d prefer a more permanent solution but this works until LG or Sonos release an update.

I’m having a problem with a new A/V system.

The sub and surrounds disconnect from the SONOS ARC when the TV is turned on.  If I power cycle the SONOS ARC the surrounds and sub reconnect most of the time sometimes I have to power cycle all the Sonos components. I also get the surrounds and sub to reconnect by turning off the TV and waiting about 10 minutes.  But as soon as the TV is turned back on they disconnect.

I only have this problem when using the HDMI eARC connection.  If I use the optical adapter the sub and surrounds don’t disconnect but I don’t have volume control and can’t use all the features of the SONOS ARC.

I’ve tried every fix listed on this site, none of them fixed the problem.  Also everything worked fine until I got updated by both LG and SONOS so I don’t know who broke the system.

OLED77CXAUA Firmware ver 03.23.15

SONOS ARC Firmware ver 13.2

SONOS ONE SL Firmware ver 13.2

SONOS SUB Firmware ver 13.2

Anyone have a fix out there?

That sucks. A few things I can suggest, although it’s pure speculation from my part. Can you try connecting all the Sonos speakers via ethernet, as well as the tv? 

I’m also on that firmware on my 65” CX and my Arc. I know there’s a beta LG firmware that's out for Dolby Vision gaming (probably among other things). You can try contacting LG for access to it. I’m also not sure if you can manually download an older firmware to go back a version so you can test - but might be worth checking out?

I made a mistake in my last post, the ARC does discount from the SUB and ONE SL’s when the TV is turned on and it’s using the optical port.  It just needs to set overnight with the TV off and when the TV is turned on it disconnects from the SUB and ONE SL’s.  The ARC continues to work otherwise and when the TV is turned off it reconnects to the SUB and ONE SL’s.  I can also get it to reconnect by power cycling all the SONOS components.  I’m using the IOS Sonos APP to monitor the ARC.  I’ve tried wired and wireless modes, it’s not an RF interference problem because I can get the system working by cycling power on all the SONOS components after the TV is on. Once it’s working it stays up until the TV is turned off for a couple hours and then turned back on.  Everything is pointing to a firmware bug in the SONOS components.

Is there a way to back up the firmware version on the SONOS components?

QuiXilver do you have a Sonos ARC connected to your LG CX?  Are you having problems with it?

Yeah I just bought the Sonos Arc a few weeks ago (my first Sonos product). And yes, it is connected to my CX via hdmi arc. I enabled eARC on the tv and set the digital sound out to Pass through. I've had minor issues:

• Netflix on the tv app sometimes stops outputting sound but it's only happened between episodes as opposed to randomly while an episode is playing. It appears the Sonos loses the hdmi arc signal. If I change the source to internal then back to hdmi arc it solves it. Or a reboot of the tv also helps.

• The same happened to my Xbox Series X once and if I remember correctly the same solution helped

• More confusing is my PS5. Sound stopped all of a sudden after me not changing a thing. I had to set the sound format from lpcm to dolby for it to work. But a better solution to keep lpcm was to set the hdmi audio in on the tv to pcm from Bitstream. 

But mine are minute compared to yours. I had a similar issue with a samsung hw-k950 soundbar some years ago. Rears and sub would disconnect from the main bar. I think mine was interference though hence my suggestion of wiring your setup.

I know it's a long shot but if you don't get answers from Sonos here, try reaching out to a youtuber Peter Pee or Jonah Mathes. They've done some great reviews on Sonos products. Peter’s is very in depth and I feel if anyone can help, it'll be him. I really hope you come right.

I meant to ask you - have you tried removing the sub from your setup and leaving the sl’s and arc connected? Then connect the sub and remove the sl’s. Does it behave the same in these scenarios? I'm wondering if one of them are causing the issue.

I have a better understanding of the problem, it has nothing to do with the LG CX.  I have the same issues when the ARC is connected directly to the BD player.  The only thing that seams to work is to wire all the componets together on an ethernet switch.  This is a Sonos ARC problem.  I’m going to repost to a Sonos ARC problem stream sense this is not an issue with the LG CX

Wait. When you said you tried connecting them on ethernet before, what were you connecting them to? 

I wired all the Sonos components together on the same ethernet switch the problem went away.  They only fail if the Sub and Surrounds are wireless, the ARC can be wired or Wireless and the system still fails.  I moved all the Sonos components away from everything else (12 feet) and it still failed when the audio stream was started (HDMI_ARC or Internet).  But after talking to support Friday, giving up and going to sleep (with the system still failing), the system started working Sat and has not failed sense.  So I’m in a holding pattern on this issue now, can’t fix something that’s working.  I put the components back together in the theater room and watched a movie last night, it worked great and sounded great.  Keeping my fingers crossed.  

Same issue.  I have a new LG 87” connected to my Arc via the eARC HDMI port utilizing an expensive high bandwidth return cable.  My system is connected to a Sonos sub and 2 Sonos One wirelessly.  My audio drops daily, whether I’m on cable (Xfinity) or AppleTV.  Always requires a reset.  Not good for a $2k+ system.