PCs are used as source devices or digital workstations, so the graphics and sound card manufacturers don’t add arc/eArc support to their products.

The ability of a PC to bitstream Spatial Audio is down to the software rather than hardware, other than the hardware being able to support hdmi signalling it is entirely a software responsibility.

Unless you are intending to run other services on the pc, or just want the fun/challenge of building your own a media player that supports the software you need to playback media with relevant audio support will be a simpler and more cost effective route.

With a HTPC you will also need to take care of remote control and if you want hdmi-cec support usually need an external cec adapter. If you want to play streaming services with it is hit and miss whether the provider will allow the same level of video and audio streams vs their tv or media player apps.

Plugging the HTPC into the TV and the soundbar into the TV arc/eArc port will allow playback of Spatial Audio as long as you have appropriate software installed and configured.

You could add an additional adapter, from someone like hdfury, to sit between the PC and TV to extract audio to an arc/eArc port with the sound bar plugged in, but it is an unnecessary complexity if the TV supports passthrough of all the audio formats you require.

Hi Sigh, and thanks for the reply. I mainly want to game on a bigscreen TV with 7.1.4 spatial audio if possible. Streaming the TV will take care via Android TV, so not too fused about that.

You have to keep the TV ARC connection to the (not confusingly named at all) Sonos Arc soundbar. HDMI is just an Audio Return Channel that was mainly to allow home cinema amplifiers to have your sources connected there, and for the TV to be able to send its sound back to the amp for internal TV/app sound. The Sonos (and many other) sound bars generally don’t have lots of inputs, but take advantage of that. 

Assuming your HTPC will just use the TV as its screen you should just be able to plug it into any spare HDMI on your TV. 

The ‘problems’ with PC hardware and playback comes from getting a full hardware chain that adheres to HDCP (the copy protection) rules in order to get raw bitstreams etc. If it thinks there’s any chance of ‘snooping’ then sometimes you get downgraded sound/picture or nothing at all. 

So you need software + hardware for things like Blu-ray playback if you intend to do that. 

Of course if it’s all rips with the copy protection removed then it becomes easier. 

You’ll likely want HDMI 2.1 or higher depending on the resolution etc you want to play. The Sonos shouldn’t limit this as it’s just going to handle sound from the TV via ARC.  

I have my Windows gaming pc plugged into my TV.

Install the Windows Dolby Atmos app, for home theatre there is no cost, it’s just for headphones they charge.

Select Dolby Atmos as the speaker configuration, rather than 7.1, and the TV eArc will deal with sending the audio to the soundbar.

Is there any lag in your experience? For me xbox there was then again maybe it was just a xbsx thing.

Thanks for the reply Ian, which means the codec on the motherboard does not matter right? Since I am connecting the GPU hdmi to the TV.

With the pc haven’t had anything noticeable.

When I had an XBSX, like you I had audio delay with Atmos enabled for games, about 1-2 seconds. No problem using the Xbox as a media player with Atmos, just for games. It’s a long standing Xbox issue that goes back years. Generally it is reported against LG TVs as a LG issue but that is due to the volume of XBSX plugged into Lg TVs, I had the delay with XBSX and my Sony TV and the Sony HT-A9s I was using at the time.

Sony X90H here, and there were some also saying it was fixed on Reddit, but not for me. Glad it is not on PC. May I ask what GPU are you using?

I don’t think so, but it’s probably worth asking in a forum for the graphics card you’re looking at to confirm. Sometimes you can get some left field off-loading of processing on PC’s… I gave up on HTPC’s a while back as I found it a bit too hit & miss, but I’m not a gamer so … 

At the moment an Amd 7900XT, I haven’t used Nvidia for a long time. With wanting to be able to dual boot into Linux I found Amd worked better for the things I do.

My Windows PC is basically a Steam launcher, so I had been hoping to turn my gaming PC into a Steamdeck style appliance when Windows 10 goes end of life if all the games I play work, but the hdmi.org blocked the Amd drivers with hdmi 2.1 & VRR so I’ll likely either need to stay Windows or get a new video card next year to switch 

For gaming it doesn’t matter. The Microsoft Spatial Audio APIs and Dolby Atmos app deal with it and send as Dolby MAT I think, would need to check what my AVR is receiving.

With the plugin graphics card hdmi port it doesn’t use the motherboard codecs. It uses the Amd/nvidia/intel hdmi audio drivers included in their driver package rather than the motherboard drivers.