Multichannel PCM 5.1 dropping out since 14.10 update

Disagree on the basis that my LG TV with an alternative brand eARC amplifier, and it was stated earlier that a Sonos ARC replacement also resolved the issue. Also, the logistics of returning a soundbar are less of a drag than a large, configured TV.

@yofalat611 raises an excellent point though - I've been assuming a firmware issue to date. A hardware problem, or even a hardware revision problem, opens up some more tests:

1. Test my Beam2 against another CX-C2 TV. @kikeminchas has shown how to get the drop outs to appear on demand, so this seems more feasible during a family visit. (I have an A1 but I'll have to take it off the wall again to access the rear facing eARC port which needs a family member to visit me)
2. Test a replacement Beam2 against my C1. I guess I'm out of warranty now, but has anyone else returned their Beam2 for a replacement and resolved/retained the drop outs?

@ste_ms,

Just being devils advocate… I’m just wondering where a manufacturer stands then, like Sonos, if at the time of releasing their Beam soundbar it works with all major brands of TV (available at that point in time) and then after it’s launch, a manufacturer like LG, launch a new TV model with a different chipset that is not supported/compatible with the Beam.

I don’t see how anyone could return a Beam (outside of its warranty), if those were the circumstances and the sequence of events - so that’s why my thoughts would be to return the TV, that’s if it’s launch perhaps occurred afterwards and the LG device that was not compatible - but I appreciate returning the TV is not the easiest option to do, but seems a little unfair if I look at it from Sonos’ point of view.

Of course it’s incredibly difficult but that is the arena in which Sonos have chosen to develop their products and therefore they need to have deep relationships with the TV manufacturers and constantly update their software to manage this risk.

It’s the same as Apple and Samsung - their phones have to work with the cellular networks and I’m sure that is a constant process with the network operators to maintain that functionality over time. 

Personally I would be more than happy with confirmation either way that either Sonos is looking into it, or that they have and it can’t be fixed so I could make an informed choice on what to do next. But instead we are left in limbo for months on end with no communication or acknowledgement whatsoever which is the absolute worst part of all this.

Only applies to the C2 in this case if I’ve got the dates correct (Beam 2 was available from Oct ‘21). Of course, h/w revisions and firmware updates do make the situation more complex, and what’s to stop the TV manufacturer using the same argument with newer sound bars?

Sonos UK EULA states under “10. Warranty and Disclaimer”:

SONOS DOES NOT WARRANT THAT THE PRODUCT(S) WILL OPERATE WITHOUT INTERRUPTION OR WILL BE ERROR-FREE, OR THAT ALL ERRORS AND/OR DEFECTS MAY BE CORRECTED

If any of this was actually how things worked, no-one would be able to return anything...

For what it’s worth, my hardware versions of the Beam 2 are as follows:

Hardware Version: 1.35.1.6-22

Series ID: A200

Manufacture date code: 2107

I was looking for a potential Beam replacement and came across the new-ish Bose Soundbar 600. Checking for feedback, I saw that they had an issue with LG OLEDs where it did not produce any sound at all. However, unlike Sonos, Bose was quick to acknowledge the issue and eventually released a firmware update to fix it. You can do a search on the Bose subreddit if interested.

Bose’s was a major issue, sure, but Sonos should also show accountability. I sound like a broken record but if it works on the Arc, why is it busted on the Beam? Pretty sure this is a Sonos issue.

I finally returned my Beam and One SL and got a refund. No more issue with a new Samsung Q930b.

Good for you! I myself am thinking of selling my Beam and moving on to another brand. Just waiting for a good deal.

So Samsung works… Bose works (and when it didn’t, Bose admitted it was their bad)… Sony works (we have a Sony eArc soundbar and it works perfectly)… Unless someone says otherwise, I would assume LG works since it’s their own TV and soundbar lol… Sonos Arc works…

At this point, if anyone is still convinced that this is an LG TV issue and not a Sonos Beam issue, I don’t really know what else to tell you. We may not have all the facts but with what we do have, this is undeniably the most logical conclusion.

Found a Lattice Semiconductor white paper that explains eARC why it’s not that simple. I learned a few new things today:

• eARC uses the HDMI Ethernet Channel (HEC) pins in a “with Ethernet” cable, I’m assuming this means that HEC and eARC are exclusive (which is no big deal since apparently HEC implementations are extremely rare) rather than eARC runs over HEC
• eARC operates independently from the video pin TMDS/FRL groups, hence any HDMI speed cable would be eARC compatible so long as it is wired for “with Ethernet”
• eARC does not require CEC to transmit the audio signal. This includes the device discovery during initial handshaking for which ARC does seem to rely on CEC. However eARC does not provide volume/power control capabilities which typically will be provided by CEC, or simply the remote control on the audio device
• eARC audio signal is “similar” to SPDIF but offers a maximum of 8 channels, 24-bit, 192KHz
• To achieve the above, a 1 Mb/s bi-directional data signal is overlaid onto the audio signal which provides (and this is the crucial bit):
  • discovery of supported audio formats
  • lip sync control
  • heartbeat
• discrete eARC to I2S bridge ICs are available which use only the eARC pins

Whilst ingesting a SPDIF-like signal should be bread and butter work for a Sonos device:

• what does the lip sync protocol look like?
• what happens if a heart beat is missed?

How much of the protocol is implemented in the ICs and what remains for the SONOS s/w to fulfil? If there is a bug in such an IC (TV or soundbar side) what are the chances of a fix?

This may not actually be a SONOS vs LG thing, but a Lattice vs ITE thing (I’ve no idea what, if any, manufacturers eARC ICs might be in these devices)

I managed to uncover an entirely different eARC problem with a Sony soundbar connected to a C1 whilst investigating got Beam 2 drop outs, so I’m not about to jump ship just yet...