Beam: Keeps switching back to ARC from Bluetooth - how to stop?

Thanks for all the replies. 

Seems like CEC needs to an update to read what audio output the TV is set to. Something LG / Sonos and whoever oversees the CEC protocol need to work together on. It’s supposed to be a “smart” solution, so its understandable why users don’t like the way it works in its current form.

Before EArc/ Soundbars / Sonos etc, most enthusiasts had their home theatre systems running through AV receivers, which although bulky allowed the user to easily switch inputs to pick and choose what goes through the speakers. Intuitively, it seems like the newer systems should work in a familiar way.

Anyway - solved the problem by plugging the Sonos beam into one of these -
https://www.bunnings.com.au/arlec-white-grid-connect-smart-plug-in-socket-with-energy-meter_p0273367

We just use Google home to cut the power to the Sonos Beam if we want to force it to use the TV speakers or the TVs bluetooth audio output.

Just bought an arc/sub/ones as a full surround setup for over 2k. 

I use Bluetooth headphones at night when my other half has gone to bed. My other half uses the headphones when I work nights. I cannot just simply turn off CEC as it auto-enables. I would need to change multiple settings, every night & teach my other half to do the same. It also increases the chances of the sound coming out of the wrong device which would accidentally wake the other person. I cannot run through optical as I lose Atmos. This is a non-negotiable use case. I went with Sonos because it’s just supposed to work. 

Attitude from Sonos CS on this issue is very poor - advice to use optical shows fundamentally poor understanding of their products & end users. They’re being returned, fortunately within 100 days so the only person losing money is them. There is a lot of competition in the wireless surround market and I will just go with a competitor. The sound is great but nothing special at this price point, what appealed is they were just supposed to work. Janky work arounds like setting up a smart plug are not acceptable on this system. 

Make sure that whatever system you go with, you aren’t utilizing HDMI-ARC/eARC technology (which will include CEC).  It needs to be something where your sources connect to the audio system first, and your audio system connects to the TV.

And I agree that setting up a smart plug, while might be ok for some, it’s really an ideal solution.  For one thing, Sonos products are designed to be always on.  While the occasional reboot is fine, it’s not good for the life of the speaker. You don’t really want to cut power and reboot every time you switch between headphones and speakers.

@RBM1505 
As Danny mentions, whatever system you go with next, ensure it doesn’t use HDMI-ARC/eARC with CEC as you’ll certainly just end up with the same issue.

I also agree that powering off the Arc is not the answer - but I would certainly get in touch with the TV Support desk to make them aware that CEC is auto-enabling itself on the TV as ‘that’ is clearly a TV fault with the TV firmware.

I use an LG C9 TV and to switch from the HDMI-ARC/eARC output  to use Bluetooth output, I just toggle off ‘CEC’ (calked ‘Simplink’ on an LG TV) and it automatically disables auto-power-sync (used to power devices on/off) and clearly in the case of your TV that is not working as it should be. I would certainly make the TV manufacturer aware that has caused you an issue here and that it may arise in the future too if you have other CEC enable devices connected to the TV that ‘may’ go onto occasionally steal the output port focus when listening to the audio over a Bluetooth connected headset.

If you disable CEC on the TV - it should stay disabled.

Do you have eARC enabled? 

I have an LG C1. I can get CEC to remain off, I just have to turn off eARC in audio settings first. 

From looking around this doesn’t seem to be an issue with the q950a for example, nor the Bose systems. I will find out soon enough once this return is processed. 

The Q950a has HDMI inputs(source) and outputs to the TV.  It does have eARC, but I doubt many users are turning this on, as it would only be needed for TV internal apps.  And it would be a smaller subset of people who use eARC and bluetooth headphones...and the TV CEC doesn’t stay off.

@RBM1505,
Yes of course eARC and CEC are both initially enabled when using the Sonos HT products and CEC (Simplink, or it’s equivalent) must be ‘disabled’ by the user on any/every brand of TV to then use the Bluetooth or any other type of audio output that the TV has.

That’s how the LG TV works with CEC (Simplink) - but once CEC is toggled ‘off’, it should switch off auto-power-sync too (automatically) so that there is then no way the Sonos device can then take back control of the TV (and vice versa) and use the HDMI-2 (ARC/eARC) port. 

CEC should not (ever) auto-enable and switch back ‘on’. If that’s what is happening on the C1, then it’s a firmware fault IMHO - CEC should stay switched ‘off’ allowing you to use your Bluetooth headset.

This will happen with any HT device that uses the TV’s ‘audio return channel features’ with CEC control - but once you switch CEC ‘off’ to use the Bluetooth headset - the TV should not switch back to outputting to the Sonos Arc until you re-enable Simplink (CEC).

It should be a simple case of toggling CEC (Simplink) ‘off/on’ to use your Bluetooth headset and HT system and if that’s not the case, then it is the TV firmware that’s likely at fault.

Even if we were to ask Sonos to ‘fix this’ by switching off CEC at their end - you would find yourself going into the Sonos App settings instead to switch off CEC on the Arc - it’s just as easy, if not far easier, to switch off CEC (Simplink) in the TV settings, plus it’s a toggle feature/option that every TV has already - so it’s not something that Sonos needs to fix anyway IMHO. 

I could use something like the Q950A + an Nvidia Shield and that would be cost neutral to the Sonos return. Plus I have a bit more functionality with the Shield. 

I tried to turn off auto power sync on the TV and it just re-enables itself - same issue as Simplink. The only option to get this current setup to work would be to either unplug the HDMI (PITA to faff about behind the TV daily) or smart plug which as you say is bad for the speakers. Due to lack of HDMI pass through on the Arc I am limited in work arounds. 

Figuring out if this a fault with the LG or Sonos doesn’t really help me - this issue seems to have been going on for >2 years so I think a software update from either side is unlikely. The Sonos is within it’s return period but the LG is not, so the Sonos system has to go back. 

Same issue , sonos amp. Please sonos fix this problem.

One other potential solution is to use an HD Fury Arcana, as that would bypass using the TVs eARC and CEC.  Arcana isn’t cheap though, and you would need an external source like a Shield.  So  I would understand if you just want to go with the Q950A for budget reason. 

It clearly sounds like an LG issue, but LG has little motivation to fix audio related issues on their TVs.  And your return period does matter.