Arc/Atmos - TV support for passthrough from Apple 4k?

I find your logic odd. It’s Apple that is apparently restricting the Dolby Atmos signal to MAT, not Sonos. Assuming you can hand the appropriate signal to Sonos, it will play it. Sonos has zero control over what systems you TV supports. I’m not sure what Sonos can do, other than to petition Apple to change their stance, and we’ve seen how well that has progressed on the ‘on this device’ front. 

If, and I stress the if, this is a problem with Apple TV, it lies directly on Apple’s shoulders, and the TV sets we’ve purchased. Sonos has said they’ll play Atmos encoded in Dolby Digital Plus over HDMI ARC, and in TrueHD over eARC. How can this be laid at their feet?

I will reserve my judgement on Apple TV until I see how my Vizio passes the signal to Sonos...and if it still doesn’t work for me, I’ll reserve my complaints for Apple’s refusal to use anything other than MAT, and me for purchasing a TV that Doesn’t support eARC, probably in equal measure. But it’s not a Sonos issue, by any stretch. They’re just the receiver of the signal. 

I’ll reserve judgement too. It’s early days - the product isn’t shipping yet! 

But I’ll be on the lookout for guidance from Sonos on how the Arc can be used (or not) with an Apple TV and a modern (2020) TV with eARC. If not, well, being handed a reason to buy a new AVR wouldn’t be the end of the world. :-) 

Dave Ings

Don’t blame Apple. The fact is that it is the receiving device’s job to interpret audio signals, if the receiving device cannot do so then it is just not up to date with common audio signal processing.

The stance you are taking is basically: Sonos says our receiving device does type X audio processing, so every manufacturer of tech equipment in the world must now support products the way we do, thanks. The correct way to handle it is: We understand that there are a large variety of audio signal processing methods, our receiver is prepared to support them.

And no I don’t care if you disagree. The fact is that Sonos and Bose are the only two audio product brands that take the approach of “my way or the highway because everyone else can go F themselves if they dont do things the way we do”

I’m in a similar boat — currently I have a non-ARC projector connected to a Sonos Beam via an HDMI switch that has an S/PDIF optical output. This works well enough, but looks like it would have to change if I upgrade to the Sonos Arc and wanted Atmos audio.

I understand Atmos is not supported with optical, so I’m looking this “HD Audio Extractor” which splits HDMI into HDMI + Audio-Only HDMI: https://smile.amazon.com/OREI-60Hz-Audio-Converter-Extractor/dp/B07T6CDPQJ/ (It claims to support Atmos).

So in theory I could plug my HDMI sources into the input, with HDMI out to the projector and Audio-HDMI to the Arc. Maybe that would work?

Won’t work. The Sonos hdmi is an output not an input and only supports ARC/eARC audio so it will ignore audio on regular hdmi channels.

Sonos isn’t know for budging on these things so I think the best bet is to reach out to the support at hdfury (a third part company known for similar products) and continue to let them know their is an interest in such a product. Enough interest and one may be created.
 

It would also be interesting if someone did a teardown of the optical to hdmi adapter that comes with the beam and arc since it is the only known device that is able to input audio to Sonos device hdmi ports and my give some of the more tech inclined forum members clues as to a solution.

This device does claim to have ARC audio out, but yes, hard to know until the Sonos Arc actually ships and we can test it out for real.

These devices seem to support eARC pass through coming back from the TV and sending it out. They don’t appear to create their own eARC output from an HDMI source input. 

It’s just poor wording for extracting audio from an arc connection that has already been established between a device and an arc television. The specs claim the audio comes on a blanked out 720p video stream.

Hello everybody,

I’m also considering buying the Arc (and also a new TV when there is a nice offer or so). Since my room isn’t that big, my 5.1 Sonos Beam Setup is totally fine. Therefore, the only reason to upgrade is the Atmos support.

Since the Arc only have one HDMI port, the TV has to pass through the audio signal from the media player right (e.g. Apple TV)? As far as I know, there is no TV on the market right now, which is capable of passthrough an LPCM signal. For example, the Sony AG9 (which is Sonys OLED flagship right now) can only passthrough Dolby Atmos via Dolby TrueHD and eARC (https://www.rtings.com/tv/reviews/sony/a9g-oled). So, therefore, it would make no sense if the Sonos Arc would support LPCM since there's no possibility to get an LPCM audio signal to the Arc. I’m not an expert so I might have a fallacy somewhere, please correct me if I’m wrong.

Regarding the Apple TV, I haven’t found a source that confirms that the Apple TV outputs LPCM audio formats. On the official Apple website, it only says “Apple TV 4K uses a high bandwidth form of Dolby Atmos that doesn’t work over ARC connections.” In this discussion, however, thy guy says, that Apple is using the Dolby Metadata-Enhanced Audio Transmission (MAT) format. As far as I understand from this document (page 12), Dolby MAT is PCM audio containing Atmos Metadata and is unpacked from Dolby TrueHD bitstreams. The Xbox is also using Dolby MAT because it is an audio format which is already decoded when it enters the TV and therefore there’s nearly no lag. Again, I’m not an expert and might have somewhere understood something wrong.

But since Sonos Arc supports Dolby MAT, we should be able getting lossless Dolby Atmos using our Apple TV, shouldn't we? (Assuming the TV has an eARC port which is needed for Dolby TrueHD and Dolby MAT)

I agree with your logic. I’m concerned that you’re going to be retired from F1 when it resumes.

There are relatively few TVs on the market that can deal with a TrueHD (and I assume MAT) signal, which is mupildly frustrating. I’m pleased that Sonos has ‘future proofed’ the Arc for new TVs coming, but right now, I’m not sure that my Apple TV is useful for Atmos content, such as there is. I am continuing to look for an external device that will take the HDMI signal and convert it to an eARC signal before the video is passed to the TV. I imagine this will be somewhat more expensive, if it’s made, than the simple HDMI switches that just pull off to an optical output, or still use the electronics in the TV to pass back that ARC or eARC signal. So far, I’ve not found such a device, but seeing as the potential market for such has increased, I have to wonder if it won’t show up soon.