My personal thoughts would be that the ‘Dolby TrueHD’ format will work using the latest v6 infuse App on Apple TV 4K.
 

However I don’t think the infuse App will transcode the DTS format to Dolby 5.1. in which case that ‘may’ not work for you and you may have to transcode the movies manually with some software, but try it first and see if the infuse software can do these things ‘on the fly’. I can’t find anything online which mentions the software will transcode, but I’m fairly sure that the new Sonos ARC when launched (or any current sonos HT product) does not support playback of the DTS codec.

Thanks for weighing in here, @Ken_Griffiths. My doubts around TrueHD specifically was that when digging around I kept coming across people saying that Apple TV 4K outputs TrueHD as LPCM unless its the native apps, which apparently Sonos Arc won’t be supporting. I wonder if that changes things?

I’m really not certain and don’t want to give you misleading info, but just to say if you’re pre-ordering/purchasing the ARC direct from Sonos, I understand you can return it, if it doesn’t do what you need it to do… so you will be okay to perhaps try these things.
 

I’m pretty sure though that the DTS encoded audio won’t work.

The LG C9 is a great choice for advanced video tech, but its not really possible to say how well it will work with the Apple TV and the Arc together until someone gets to try it as the Atmos story on that combo is unclear. Any problems are unlikely to be the TV’s fault in this case.

Thanks, @controlav. I understand, just nervous, that’s all.

Well… I’ve got Arc on pre-order for June 10th ship/delivery so perhaps in a nice turn of events I could go from ‘naggy quesitoner’ to being able to return to this thread and confirm whether or not it works for me, and thereby others!

If it doesn’t work because of an LPCM support issue, that’d be a crazy missed opportunity for Sonos - because this is surely a fairly common use case.

All fingers and toes crossed, though. I really hope it does work becuase I want to want to keep it!

I question if “LPCM” is a common use case, as multichannel PCM cannot work over ARC, it needs eARC which is pretty rare still (outside of your home, and my office which is where my LG C9 is, sitting all alone as I have to work from home now).

The soundbar scene has been a mess due to the different connections, some major brands are still toslink only while others carry multiple hdmi inputs and act as receivers in that sense. Means that soundbars haven’t been a viable choice for a lot of people, who have had to go with massive receivers.

Now earc would allow you to have the tv take over the traditional switching role of the receiver, keeping the video and passing the audio on to the audio devices via earc (as opposed to the receiver keeping the audio and passing on the video to the tv).

This means that audio devices don’t have to support the latest video formats any longer, which is probably a major relief to everybody, certainly the consumers who no longer have to rebuy receivers just because hdmi went up with .1.

In fact, earc allows for a major simplification of the audio part of the home theatre. It (the receiver, the soundbar acting as the hub of a wireless 5.1 system etc.) just has to accept the necessary formats and do the audio well, nothing else.

Of course, the key issue here is that the Arc doesn’t accept the necessary formats, as they have chosen to link themselves with dolby, while ANY device that I am aware of (admittedly, I am not conversant on all the discount streaming boxes) can output any audio, no matter the origin, as multichannel pcm. 

Hence, you get people like me, who still can’t use all their devices with the Arc, contrary to, at least to me, the whole basic premise of the earc tech. While this may not seem like a glaring oversight now that earc is new and not on every single device, the necessity will, IMO, become apparent soon.

TrueHD wont work with Apple TV as it doesn’t support TrueHD. Infuse however supports Atmos with DD+. See here Firecore AtmosThread 

Hi shnuggleberry,

I am in a similar situation, i was just about to buy the ARC but the more i read about Atoms support the more i get confused. I have the LG C9 with a Beam and 2 play 3 speakers as rears at the moment and thought swapping the Beam for the ARC would be a huge leap in sound Quality. I am no serious audio tech freak, i just want to turn on my TV and get the best sound using PS4, Virgin media box and the Apps stored on the LG TV. But what i’ve read kind of puts me off. I would be interested to hear how you get on testing the ARC and what problems u encounter. As i said it might not be worth it for someone like me who just like to turn it on and have the best sound quality possible without the need for adding other equipment. Cheers.

Hey @Sheridan82… I absolutely will. The crazy myriad of options (crazy, probably, because I’m new to this world) seems to mean that I’ve got really contradicting answers from very well-meaning and helpful people across this Sonos forum, and the forum for the Infuse app in question that I’m concerned about.

TrueHD compatibility in 3rd party apps on Apple TV 4K, Apple TV 4K sometimes outputting LPCM, Sonos Arc apparently not supporting LPCM. It’s definitely all got the better of me ha!

I’m usually just someone asking all the questions… but this time, as its been so frustrating - I’ve kept my Sonos Arc pre-order, and will absolutely test a bunch of different scenarios and come back to share my findings for others.

If Sonos has released a £799 Atmos soundbar that doesn’t wholly support Atmos with an arguably very popular streaming device, even when being used with a rare eARC-equipped TV, it’ll be very dissapointing and I’ll likely return. A few days back I was thinking Apple were more to blame for not outputting the right audio, but it seems that LPCM is really commonplace and seems to be in favour of avoiding compatability issues. @Sonos Pleeeeeease just make it work haha!

i'm new on this forum… but is this a solution https://www.hdfury.com/product/4k-arcana-18gbps/