SL One rears hissing

Hi @aviHil.

Welcome to the Sonos community and thanks for reaching out to us. I understand your situation and it can get quite irritating especially when there is no other sound except that hissing sound. Let me ask some questions to better understand what is going on and thanks for going the extra mile on looking for answers in different forums.

• Since when did the issue start to happen?
• From the start of setting up your Home theater was the sound already there?
• Just to be clear, “I’m downsizing from a regular amp/speakers 5.1 set up, and I would never hear anything coming from the rears when it wasn’t supposed to.” does this mean when the Sonos OneSl is not bonded as surrounds, there is no hissing sound?
• Does the hissing sound only happen when the home theater speaker is not in use?
• Can we try to unplug and plug back the power cable from the power outlet and the bottom of the Sonos One Sl and check if the hissing sound is still there?
• Can we try to move the Sonos One Sl to a different location and check if the hissing sound is still present?
• Can we try to follow this guide about wireless interference?
• Can we please check if there are any other electronic devices near the Sonos One Sl and try to move it away from the Sonos One Sl and check if the issue is fixed?

Please let us know how it goes. We are always here to help out.

Thanks,

Hi Paul, thanks for your reply. Please see my answers below.

• Since when did the issue start to happen? 

As soon as I started using the units. All brand new, direct from Sonos.

• From the start of setting up your Home theatre was the sound already there?

Only when the surrounds were bonded. I first noticed it when I hit pause on a movie. It should have been silent, but instead there was faint hiss of white noise from both surrounds. It stops after about 30 secs. I also noticed it watching stereo content which had no audio information for the rears to play.

• Just to be clear, “I’m downsizing from a regular amp/speakers 5.1 set up, and I would never hear anything coming from the rears when it wasn’t supposed to.” does this mean when the Sonos OneSl is not bonded as surrounds, there is no hissing sound?

No, apologies for the confusion. That’s just to say that I wouldn’t expect to hear a hissing noise, however faint, coming from rear speakers on a regular 5.1 setup. I had a completely different wired surround system before.  

But to answer your question, yes, the hissing sound only appears when the speakers are bonded as surrounds. I haven’t heard it when I’ve tried them as a standalone speaker.

• Does the hissing sound only happen when the home theater speaker is not in use?

It’s basically when the surrounds are ‘armed’ and the sound bar is playing / just played content. After about 30secs of not playing content / powering off TV, the hissing stops.

• Can we try to unplug and plug back the power cable from the power outlet and the bottom of the Sonos One Sl and check if the hissing sound is still there?

yes - It’s definitely only when the speakers are on and ‘armed’.

• Can we try to move the Sonos One Sl to a different location and check if the hissing sound is still present?

yes - I’ve tried moving one of them to see if it makes a difference. But to be honest, the behaviour is simultaneous in both surrounds, so I believe it’s to do with the way they work when ‘armed’ for surround, nothing to do with interference or positioning.

• Can we try to follow this guide about wireless interference?

I can try this and report back.

• Can we please check if there are any other electronic devices near the Sonos One Sl and try to move it away from the Sonos One Sl and check if the issue is fixed?

They are the only devices in that area, each surround in it’s own power socket.

Hi @aviHil.

Thanks for the immediate and detailed response.

I would like to recommend if we can submit a diagnostic and contact our technical support team for a more in-depth troubleshooting step or possible product replacement. We can also try to check TV audio quality and set it to PCM then observe if the issue still persists. 

Please let us know how it goes. We are always here to help out.

Thanks,

Thanks very much. Here’s a diagnostic number 581545302. Should I send that straight to tech support.

Hi @aviHil.

Thanks for submitting a diagnostic and for your immediate response. 

Based on the provided diagnostic, It seems that the TV is turned off. We may want to consider turning the TV back on, wait for a good 5-10 minutes of the TV playing a movie and submit another diagnostic so we can capture the audio format from the TV to your Sonos Home theater system.

Please let us know how it goes. We are always here to help out.

Thanks,

Ah, in that case,  I’ll create a diagnostic when I can hear the hissing.

Thanks

HI @aviHil.

Thanks for your immediate response.

Sure thing. Please take note of the confirmation number and post it here so we can check it for you.

Please let us know if you still have further questions or concerns. We are always here to help.

Thanks,

Thanks, here’s an updated number 784402699.

I had a movie playing and then paused it to recreate the issue.

Hi @aviHil.

Thanks for submitting a diagnostic and for your immediate response.

Based on the provided diagnostic, the audio codec from the TV going to the Sonos Beam is PCM. It is the generic audio format. Can we try changing it to Dolby digital or surrounds on the TV settings and check if the issue would persist? If yes, I would like to highly recommend contacting our technical support team for more in-depth troubleshooting steps to see what is triggering this hissing sound. You can also try unplugging the HDMI cable from the back of the Sonos Beam and TV and plug it back while both are turned off. This recommendation is a shot in the dark since I could not think of any other reason why would it generate a hissing sound for the surrounds.

I hope this helps.

Please let us know if you still have further questions or concerns. We are always here to help.

Thanks,

This conversation seems to have ended. I’d like to know, was there resolve?