No Dolby Atmos on a Sonos Arc or Beam Gen 2

The soundbar says Dolby Digital or Stereo where you expected Atmos. Nine times out of ten the format was discarded by the TV, not by the soundbar.

What is actually going wrong

A Sonos Arc or Beam Gen 2 can play Dolby Atmos in two different wrappers. Over ARC it accepts Atmos carried inside Dolby Digital Plus — which is what streaming apps use. Over eARC it can additionally accept Atmos carried inside Dolby TrueHD, which is what a UHD Blu-ray disc holds.

The catch is what sits in between. When your source is plugged into the TV, the TV decides what comes back out of the ARC/eARC port. Many TVs re-encode everything to Dolby Digital, some downmix to stereo PCM, and a TV without eARC cannot pass TrueHD at all — there is not enough bandwidth on plain ARC. Your player sent Atmos; the TV threw it away.

This is the problem the Arcana exists to solve. It sits between the source and the TV, splits the signal, and sends the audio straight to the Sonos over its own eARC output. The TV never gets a vote.

Work through it in this order

1. Confirm the source is really sending Atmos

An Arcana can only pass on what it receives. The usual offenders:

Apple TV 4K — Settings › Video and Audio › Audio Format must be set to Dolby Atmos, not Stereo. Leave Match Content on for audio.
PlayStation 5 — Settings › Sound › Audio Output. Set the output device to HDMI and the audio format to Dolby Atmos where the app supports it. Note that the PS5 does not bitstream TrueHD from a UHD Blu-ray disc; for disc-based TrueHD Atmos you need a dedicated player.
UHD Blu-ray players — the HDMI audio output must be set to bitstream or “auto”, not to PCM. A player set to PCM decodes Atmos internally and sends a plain multichannel stream.
Streaming apps — Atmos is per title and often per subscription tier. Test with a title you know carries it.

2. Check what the Sonos is actually receiving

Open the Sonos app, go to the room, and look at the Now Playing screen. It names the incoming format. “Dolby Atmos” or “Dolby Atmos - TrueHD” is what you want. “Dolby Digital” or “Stereo PCM” means the format was lost somewhere upstream — and now you know the problem is between the source and the soundbar, not inside the soundbar.

3. Verify the cabling

The order matters and is easy to get subtly wrong:

Source → Arcana HDMI IN
Arcana HDMI OUT → TV or projector (video only, from the TV's point of view)
Arcana eARC OUT → the HDMI port on the Sonos Arc or Beam Gen 2

The Sonos connects to the Arcana, not to the TV. If it is still plugged into the TV's eARC port, you have simply added a box to the chain and changed nothing.

4. Check the EDID setting

EDID is how the Arcana tells the source what the system can handle. On the automatic profile it merges what the display and the audio system report, which is right most of the time. If the source still refuses to send Atmos, the merged EDID may be understating the audio capability — some displays report a very conservative audio block. Forcing an EDID profile that advertises the audio system's capabilities is the fix. The Arcana manual covers the profiles in detail.

5. Re-handshake

HDMI negotiates capabilities once, when devices come up. After any change: power everything fully off, then start the soundbar, then the Arcana, then the display, then the source. Simply switching inputs is not enough.

If it still will not work

At this point the question is which link fails. Disconnect the display and run source → Arcana → Sonos only. If Atmos appears, the problem is EDID negotiation with the display in the mix. If it still does not, the source is not sending Atmos and the fix is in the source's own menus.

Frequently asked

Do I need an Arcana if my TV already has eARC?

Often not. A TV with real eARC can pass TrueHD Atmos through to a soundbar. The Arcana earns its place when the TV has ARC only, when the TV re-encodes or downmixes even over eARC, or when you use a projector that has no audio return path at all.

Does the Sonos Arc support eARC?

Yes. The Sonos Arc and Beam Gen 2 have an HDMI eARC input and accept Dolby Atmos over both Dolby Digital Plus and Dolby TrueHD.

Why does streaming give me Atmos but my Blu-ray does not?

Streaming Atmos rides inside Dolby Digital Plus, which fits within plain ARC. Disc-based Atmos rides inside Dolby TrueHD, which needs eARC bandwidth. If your chain only has ARC, that is exactly the split you would expect.

Will the Arcana upmix stereo to Atmos?

No. The Arcana extracts and passes through what the source sends. It does not decode, re-encode or upmix. Any upmixing is done by the soundbar or receiver.

Does an Arcana solve this?

YesIf the sound comes from an external HDMI source — a streamer, console or disc player — and your TV has no eARC. The Arcana takes the full audio straight from the source and sends it to the Sonos, bypassing the TV entirely. That is exactly the gap this device was built for.

NoIf the sound comes from an app on the TV itself. The Arcana cannot create support the TV app does not have. Work through the steps above first — in that case they usually settle it without new hardware.

For streaming and disc playback the original Arcana is enough. Only pick Arcana 2 if you also need 4K120 or VRR.

Buy the Arcana at HDfury.eu Read the specifications