Sky & Sonos

Nothing to do with Sonos.  It’s your TV that is at fault, delaying the passthrough of the audio so you get lip sync issues.

Hilarious. You blame everybody but the real culprit, which is Samsung.

Route the audio round the TV using a device like the HDFury Arcana.

Wait…you’re saying Sonos is not going to invent a time machine so that it can play the stream before it is received from the TV?

Here’s a Flux Capacitor, which may work perhaps, which I have posted here the day after tomorrow😀:

My understanding was the passthrough options were introduced so that bitstream decoding could be processed downstream to preserve (perceived) quality, rather than being an issue with processing delay. Similar I guess to aspirational bit-perfection in the HI-FI domain. Typically the picture processing is the more CPU intensive and the usual cause of noticeable delays? I have seen this issue first hand with the Sky Q box (not sure what the OP has) and I’d be surprised if the TV audio transcoding processing was introducing almost a 1 second delay in the audio stream.

https://www.samsung.com/sg/support/tv-audio-video/what-is-hdmi-pass-through/

Only a dolby bitstream blu-ray as the source doesn’t suffer from lip sync. Sky forums report lip-sync issues with Q and multiple soundbar/TV manufacturers. Maybe check through the missing details with OP before ganging up and goading them, doesn’t really help anyone coming here to look for a solution.

Sky forum does report success with the Arcana however, but it’s relatively expensive and impractical for more than once source (before adding an HDMI switch on top I think I would pack in the ARC altogether and buy an AV receiver). My gut feeling is a bug in the lip-sync ARC protocol in the Q box, but whatever. The stream pucks are now available to order standalone from glass, I’m wondering if they behave any better.

If that was the case it would not explain why the Arcana solves the issue for those who opt to bypass their TV sets when using Sky Q. I accept the Arcana is expensive, but there are cheaper alternatives (with built-in switch) such as the Feintech VAX04101A or OREI HDA-931, to name but two. I use the VAX04101A myself in fact.

Could be, but doesn’t seem unreasonable that ARC users want the devices they already own to work with the Q box in a similar way to other sources (albeit that I also doubt the issue is with Sonos) and not need to buy additional hardware just to enable usable Sky Dolby.

I don’t know anything about how those channel splitter devices actually work. Was assuming they isolate the audio and video devices by presenting the source with a dummy TV endpoint (a bit like computer KVMs) which also prevents any meaningful lip-sync protocol negotiation (which in any case would conflict with the intended outcome even if just trying to bypass the processing lag?) therefore avoiding triggering my theoretical bug in the Q box.

Or more crudely, maybe the Arcana just blocks any lip-sync messages reaching the Q box from the TV? Does passthrough setting on the TV block auto lip-sync anyway? I don’t know.

https://www.avsforum.com/threads/how-the-hell-does-hdmis-auto-lip-sync-work.1160970/

Maybe there are some auto lip-sync settings that can be turned off on the devices to prove/disprove the point, I’ll try next time I have access. 

Either way, the Q box seems to introduce a delay in Dolby (e)ARC audio when other sources do not, which rules out audio transcoding processing delay for me assuming it would be the same for all HDMI inputs. Introducing the Arcana then corrects the problem somehow.

The Q box used to be connected directly to an AV receiver, so no ARC (HDMI or Sonos!) and I don’t remember there being a lag for dolby in that setup. If it did, I could consider that the Q box just delayed all Dolby output, but don’t think that’s the case either.

Of course, if the TV is buggy and my bluray player simply doesn’t implement lip sync delay, then maybe the Q box is behaving correctly. Could take a while to validate that...

Earlier you referred to a HT ‘Receiver’ link when talking about audio pass-through, however I’m referring to the main TV audio pass-through as the main A/V master device here that would otherwise process the video to its screen and transcode the audio out through its ports - the Sonos HT product does not transcode any audio - it just plays the ‘returned’ audio sent, as soon as it arrives, with virtually little, or no, delay.

The audio delay experienced in this instant is ‘clearly’ either the sending device (Sky Q Box), or the OP’s Samsung TV. The evidence points to it being the Samsung TV, because (a) it will transcode the audio received (it does not have pass-through) and (b) it’s clear that if the Sky Q audio is re-routed to bypass the TV and ‘pass-through’ the Arcana, which ‘splits’ (diverts) the audio track from the A/V signal and directs it (quickly/no transcoding) to the Sonos Arc - it will then play all in perfect lip-sync with the video on the TV screen - there is no delay when the audio signal merely bypasses the TV ports, so that shows/infers the Samsung TV is the issue and it’s been discussed before in other threads here in the community. In fact older Samsung TV’s are often mentioned in such threads. 

The OP, despite those past threads, was clearly trying to say the issue should be fixed by Sonos, but the evidence in most cases tends to show it’s not actually a Sonos issue - it’s usually the TV, or the A/V sending device. In this case the evidence points more towards it being the Samsung TV - that’s the point I’m simply trying to highlight here.