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? 

No this was never resolved unfortunately. 
it appears Sonos devices used as rears in a surround setup, will always display this behaviour. I think less people have flagged it up because they don’t sit with the rears close enough to notice the hissing.. but it’s there.

Hi @Count D. 

Welcome to the Sonos community and thanks for reaching out regarding this topic. My last reply was a recommendation to contact our technical support team as they have more tools and means necessary to troubleshoot and help you guys out with your concern and hopefully e resolved within the same point of contact.

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

Thanks,

Hi @aviHil 

Thanks for the update and feedback. I would still like to recommend contacting our technical support team. They may find the cause of this hissing sound to get things sorted out for you. It may be a glitch, it may be wireless interference or other devices capable of connecting to the internet that is causing this hissing sound or possible TV audio codec issue. Depending on the findings or result of the diagnostic and troubleshooting done with in the point of contact with our technical support team. 

I hope this helps.

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

Thanks,

Hi all.

I just installed my two Sonos One SLs yesterday in the same arrangement as the original poster. I immediately noticed a faint hiss and it feels/sound similar to a ringing in my ears when my LG OLED is on. When I mute the TV, and get close to my rear speakers, I hear the faint airy hiss. The hiss persists for a few minutes after turning off the TV.

I also hear the hiss when playing music over AirPlay and when the music is paused. Therefore, I searched for this topic. 

Has anyone been able to solve this? If so, how?

I sent a diagnostic just in case it helps: 348230699

Thanks!

@California_Kenny Are the One SLs plugged in to two different outlets or the same outlet? If different, try plugging both speakers into the same outlet or power strip.

Are there any other wireless devices that could be causing interference near your speakers?

Thanks @GuitarSuperstar. I have each speaker plugged into different outlets. I’ll try putting them in the same one and report back tomorrow. The only wireless devices in the room are the One SLs and my Arc...and I doubt my iPhone is causing interference. 

I appreciate the tips!

Putting both in the same outlet did not make a difference. I can still hear a faint wind-like sound coming from the rears when on. Thanks again. 

Hello all

this is not a new issue but is common with Sonos and in my case a pair of Sonos Ones SLs and also a pair of Echo Studios. Both brands do the same.

The Sonos One SLs have hissed (white noise) since new. It’s not electrical interference as this would sound similar to a fax machine (but quieter).

I love music and having a white noise being audible even with music playing at low volumes is degrading the sound quality. The noise does not however increase with volume but isn’t heard when the volume of the music is increased. I listen to music all day at lower volume levels more than at higher levels. If I can hear the hissing then I’m not enjoying the music. 

There is little point in product swapping under warranty (which Sonos are good for) as it is the tech inside that is probably the cause. My only option has been to go back to a dedicated separates system and bigger speakers and even though is use a digital amplifier I do not hear white noise or digital amp whining.

Have Sonos found the cause and a solution. This was the noise that caused me to stop using my Sonos Beam. And also why I stopped using other smart speakers.