Skip to main content
velvel
Contributor I
September 24, 2025

Request for HDMI Stereo → Rear Speaker Option

  • September 24, 2025
  • 15 replies
  • 288 views

Dear Sonos Team,

When stereo PCM is sent over HDMI, the Arc forces playback through the front channels only. Sonos frames this as “purism,” but it actually blocks creative intent and creates inconsistency:

  • Artists’ intent is restricted. If a stereo track is designed to fill the room, Sonos prevents rears from engaging. Other brands allow “All Channel Stereo.”

  • Inconsistent behaviour. The Arc mirrors stereo to surrounds in music mode (AirPlay, Spotify Connect), but forbids it over HDMI. There is no technical or licensing reason — simple channel duplication costs nothing.

  • Purism becomes interference. By enforcing silence in rears, Sonos isn’t respecting the mix, it’s imposing a design choice that neither creators nor customers asked for.

It’s like buying a 4K TV, but when you watch HD content the manufacturer only lights up the centre part of the screen, leaving black bars around the edges, saying “we’re respecting the director’s intent.”

Unless there is a clear, rational justification, Sonos should enable an HDMI “Full” surround option for stereo content.

Kind regards

    This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

    15 replies

    Show previous replies
    sjw
    Local Superstar
    September 25, 2025

    Unless it's a 5.1/Atmos etc. mix, there is no fwd/rear ‘intent’, it's a stereo mix,  which is left and right.  I don't understand the pushback mentioning a creator's stereo intent being front without rears.

    People get this everyday without thinking about it - in their cars for example.  As a minimum, most cars have speakers in the front and probably the rear doors too, all in stereo.  Not having sound out of the rears (albeit the exact same sound as the fronts) would sound weird.

      velvelAuthor
      Contributor I
      September 25, 2025

      I will explore and attempt the FeinTech VAX04101A approach.  Lets hope Sonos decides to look into this though. 

      Stechi
      Lyricist II
      September 26, 2025

      So just to try to understand your issue:
      Your source is only sending the audio to the two front channels, but sends nothing to the rear channels for the media you are playing.
      You want the audio from the front channels duplicated to the rear channels.
      Did I get this right?

      I can see why this option isn’t available.
      Because if your source is playing media it probably sends a signal containing audio to the front channels, but an empty signal to the rear channels.

      So you want an option to overwrite the rear channels, but if you (or any other user) activates this and then plays an audio source which uses the rear channels, much more complaints of users having forgotten to deactivate the option, would be flooding support.

      So all Sonos is doing is playing the audio in the same way it receives it.
      So offering surround duplication only for pure stereo sources like music files or audio jacks makes sense.
      They have no possibility to know if a surround source is generally just using the front channels or if they are just not used in the moment, but later on.

      sjw
      Local Superstar
      September 26, 2025

      So just to try to understand your issue:

      No you don't.

      ‘Overwriting’ channels?  I think the OP just wants the option to have similar functionality that's already available from other play methods.

      velvelAuthor
      Contributor I
      September 27, 2025

      So just to try to understand your issue:
      Your source is only sending the audio to the two front channels, but sends nothing to the rear channels for the media you are playing.
      You want the audio from the front channels duplicated to the rear channels.
      Did I get this right?
       

      Hi Stechi,
      With normal PCM stereo there are only two channels (left and right), so technically there are no “rear channels” in the signal at all. That’s the format most apps and devices send unless they’re outputting a 5.1 or Atmos mix.

      What I’m asking for is simply the option to duplicate that stereo signal into the surrounds. Other brands seem to all offer this and even Sonos lets us do this in music mode with the Full setting, but oddly not in HDMI/TV mode.

      Terms & ConditionsAccessibility statement