PS4 Pro outputting PCM via LG CX shows Multichannel PCM 7.1 for Sonos Arc, but rear surrounds have no audio

Userlevel 2

I have the Arc, Sub, and Sonos 1 in a surround setup, connected to an LG CX via eArc. Previously I had the PS4 outputting Bitstream (Dolby), and Sonos reported Dolby Digital 5.1.

The fix that added LPCM to Sonos Arc recently went live, so I updated PS4 Pro to output PCM, and the HDMI input on the TV to PCM. (The output remained Passthrough). After doing this, the System Status page for Sonos shows Multichannel PCM 7.1.

However, I now get no rear surround audio in games like Assassin’s Creed Valhalla. (It’s not faint, there’s really none.) I get the full surround experience if I change it back to getting Dolby Digital 5.1. On the PS4 Home screen, I do get sound from the rears in PCM 7.1, albeit very faintly, compared to Dolby Digital 5.1.

Does Sonos not downmix the extra channels properly? It’s kinda bad that a higher fidelity signal sounds worse.

127 replies

Userlevel 5
Badge +11

So yeah for PS5 it’s showing PCM 5.1 ( not Dolby as I said in my previous post) but can also confirm that Apple TV 4K is still showing 7.1.

Could you confirm if you have a Beam2 or an Arc and if you get audio dropouts with pcm 5.1 in your PS5? Thanks (i get dropouts with a Beam2)

From a very quick test (Beam 2) I didn’t notice drop outs on the menu music but will try again properly later


If you have time, could you do the ff:

  • Ensure that you are on the latest Beam 2 firmware (14.10) 
  • Under PS5 sound settings, set AV Amplifier, set 5.1ch, set Linear PCM
  • On the Sonos App, ensure that it reads the incoming audio as “Multichannel PCM 5.1”
  • You can stay on the settings menu if you like just make sure your volume is loud enough for you to notice. You should get constant audio dropout every 1-2 minutes.

This weird issue ONLY seems to occur with Beam 2 on 14.10 with Multichannel PCM 5.1. All other audio formats including Multichannel PCM 7.1 work fine. I made a thread about it so if you also suffer from the same issue, perhaps you can post there and maybe someone can file a case haha or maybe with enough people complaining we can make Sonos get off their ass.


Is there no bitstream setting on the PS5, not had one is ages so can’t remember.

I have ARC here and just played some fifa and didn't notice any dropouts, so perhaps a Beam specific issue.

Userlevel 3
Badge +2

I’ve tested 5.1 output on PS5 for about 5 mins, no dropouts on Beam 2 / LG CX, latest software.