Your HDMI inputs will connect directly to the TV, and you’ll use the TV for switching what input you view on the TV. The TV’s HDMI-ARC port will connect to the Sonos Arc HDMI port, where it will get all the audio for whatever the TV is currently playing.  Your TV will be responsible for passing audio to the Arc.

You’ll potentially have two problems to deal with.  One is that your TV probably does not have 5 HDMI inputs (your 4 sources + the ARC port) so you would need to either plug and unplug your sources as needed, find a way to consolidate sources, or get a separate HDMI switch.  The other problem is that your older TV might not be passing the audio to the Arc to get the best audio possible.  

The TV has 3 total HDMI, one ARC equipped.  Connect the HDMI-ARC port to the Arc.  For that many sources, you would need a separate HDMI switch device.  Connect the source devices to the HDMI switch inputs, and the HDMI out on the switch to one of the remaining HDMI inputs on the TV.

Here’s one switch that should work.  Has auto switching for ease of use:

5 Port HDMI Switch with Remote

Thanks for the quick replies!

Not to bring back an old thread but I have a similar issue as the original poster. I have a 4k UST Projector that has 2 HDMI ports and 1 HDMI ARC. This projector does NOT support DOLBY ATMOS.  I also have an NVIDIA SHIELD which DOES Support DOLBY ATMOS. If I use the 1 HDMI ARC port between the Soundbar and Projector and use one of the remaining two HDMI ports on the Projector/TV for the NVidia Shield...will the content that I stream from the NVIDA be ATMOS compatible? 

What about peripherals? If I plug in a BLUE RAY or DOLBY ATMOS compatible XBOX into a remaining HDMI port on the Projector/TV….will the Sonos ARC (through the TV HDMI ARC port...to the Sonos ARC) be able to register, process and play the DOLBY ATMOS? 

It’s confusing. And I, for the life of me, cannot figure out why SONOS saw fit to include only 1 HDMI port. Like they know better. It’s like Apple removing the headphone jack….

Thanks in advance for your input. 

Signed, 

Perplexed in Poughkeepsie

Sonos has made a deliberate choice to let your TV be the hub for all connections. For the typical Sonos user (in short: has money bur not much technical knowledge) this is a logical choice but for the more demanding user this can be disappointing.

It is totally up to the possibilities of your projector if it is able to pass through Atmos from external sources. If it does not have this capability, you could look into the HDFury Arcana.

106Rallye- I appreciate your response. You cleared up the confusion for me with your quick and succinct reply. This is a shame tho, as I was willing to pay the hefty pricetag but will now need to look elsewhere. 

I will check out your suggestion. Thank you. And will take a harder look at what Nakamichi has to offer. 

Rick