What type of audio is displayed on the Now Playing screen on the Sonos app? Stereo PCM? Dolby Digital 5.1?

With 5.1 audio, you won’t always hear audio from the surround speakers especially during quiet scenes. The audio from the surrounds will usually be the musical score, action that is behind you, or ambient sounds. Try to test the surrounds playing an action film in 5.1.

If you are watching a stereo PCM source, the Arc will perform an audio up-mix of the stereo signal to create a simulated surround sound. This means you’ll still hear most audio out of the Arc, but the surround speakers will play what is determined to be ambient audio. Depending on the audio quality of the stereo source, sometimes you won’t hear much audio at all from the surround speakers.

You can also adjust the TV Level higher under the Surround Audio settings for the Arc.

Hi GuitarSuperstar

Thanks for getting back to me so quickly.

It says Stereo PCM.

Increasing volume made no difference (watching BBC 1) sound appears to be from the Arc only.

That said, I then played a film from a recording from my Humax and I can hear sound from the rear speakers.

Switched to BBC HD on 0101 and I can just hear the rear speakers if I put my ear to them.

Do I need to re-set them?

The room is quite large (combined kitchen/diner/sitting room) with Arc at one end and 2SLs at the other. I’m currently sitting close to the SLs but can only hear the Arc!

Hi GuitarSuperstar

I’ve just found the Surround Audio setting and increased the TV level and can now hear background music and sound effects.

So, thanks to all the information and suggestions you have given me, I think I’ve got to the bottom of it and have a better understanding how this works.

Fingers crossed.

Read this again:

If you are watching a stereo PCM source, the Arc will perform an audio up-mix of the stereo signal to create a simulated surround sound. This means you’ll still hear most audio out of the Arc, but the surround speakers will play what is determined to be ambient audio. Depending on the audio quality of the stereo source, sometimes you won’t hear much audio at all from the surround speakers.

You don’t need to reset them. They are working as intended. Have you run Trueplay tuning yet? What specific model TV do you have?

If you want to experience true surround sound, find a 5.1 audio source. Do you have Netflix?