No eArc, tv doesn't have dolby digital plus. So no atmos for me?

If it doesn’t support Dolby Digital Plus, then more than likely it doesn’t support Dolby Atmos pass through. But the only way to know for sure is to test it out for yourself or research online to see if another TX-55FX555 owner had been able to achieve Atmos audio.

You might consider adding a device like the HDFury Arcana that will allow any external media device to bypass your TV and send audio directly to the Beam which will result in Dolby Atmos audio. I use the Arcana with my Panasonic plasma from 2013.

https://hdfury.com/product/4k-arcana-18gbps/

cant find much online. will check a shop. thanks tho!

Actually I just realised that my Fire tv stick can pass atmos. So if I connect that to the beam then it should work?

The Fire TV Stick will connect to one of the TV’s HDMI ports, not directly to the Beam. Can the TV pass through Dolby Atmos audio from the Fire TV Stick? I don’t know. You just have to test it to find out.

You will need to use an input device (Apple TV, Fire Stick, Nvidia Shield) that supports Atmos.  Plug the output of such device into one of the below devices.  Connect the eARC out from the device to the Arc or Beam and the video out to the HDMI input on the TV that is labeled ARC.  When the TV is tuned to the HDMI/ARC input, it will play the video format that the input device is outputting and the Arc/Beam will play the audio format that the input device is outputting (including Atoms).  When the TV is tuned to a different input or your stream from a service via the TV interface, the TV will play the relevant video and the Arc/Beam will play the audio format the the TV is outputting on its ARC port for the applicable input.

I used the HD Fury Arcana.  It was the original device that dealt with this issue.  The OREI looks like a nice choice.  I’m likely to sell my Arcana since I got new TVs that support eARC Atmos

OREI eARC 4K 60Hz Audio Extractor Converter 3x1 Soundbar 18G HDMI 2.0 ARC Support - HDCP 2.2 - Dolby Atmos Digital/DTS Passthrough CEC, HDR, Dolby Vision HDR10 Support (HDA-935)

or HD Fury Arcana

If you’re using only a soundbar, you need to think about the question if Atmos is really that important to you. Investing in extra gear just to get Atmos will introduce a lot of extra cost an extra complexity in your set up - though I do read the thing described above work very well. The question remains if the extra cost an complexity is worth it just to get Atmos from a soundbar?

You could just try if you like the soundbar, and then decide if you’d like to invest in the extra stuff described above, or in a surrounds and/or a Sub, or in a new DD+ or eARC capable TV.

You could visit a Sonos dealer in you town to hear if the Atmos experience is really worth it for you.

The OP sought advice on how to get Atmos working on a Beam with a TV that does not have eARC.  The OP did not solicit an opinion on whether the OP should care about Atmos, which opinion is the subject of your response and off topic.

To the OP, the Arcana or the OREI device is the solution to your question unless you get a eARC capable TV.

Hey yall, thank you all for the replies. I do appreciate the questioning about atmos. I have some thinking to do, but you’re right that in order to make atmos work on my tv there’d be a few more expenses, which is why now I’m even questioning the whole sonos beam. For my tv, it’s probably too much!

I am pleased to see that the OP valued the contribution from @106rallye , as indeed he should.  It can be more helpful sometimes to query whether the right question is being asked than just to answer the question.  I would suggest that that is true in all walks of life.