2017 LG OLED65B7P TV TOSLINK Digital Optical Out Distortion


Jan 30, 2018
2017 LG OLED TV TOSLINK Digital Optical Out distortion

2017 LG OLED65B7P TV TOSLINK Digital Optical Audio Out has KNOWN distortion issues - CONFIRMED with LG Support on January 30, 2018.

My setup:
Directv hdmi -> TV -> Digital Optical Out -> Sonos Playbar
I have the TV sound in Auto mode (not in PCM) so 5.1 surround can work.

When I first turn everything on, the sound is fine.
After 10-30 minutes, strange distortion comes in after sound.
So in a tv show with dialog, every time someone stops talking (sound briefly drops) there is some strange distortion for 1-2 seconds.

Turning the tv and cable box off and back on temporarily fixes the distortion (but is a pain in the ass in the middle of a movie).

I went through support with Sonos and we determined that the problem was not the Playbar.

I went through support with LG and they CONFIRMED that this is a KNOWN problem with the tv digital optical out and that they are working on a fix but they could not say when the fix would be done.
I am posting this here so others can know that this is a confirmed problem with the LG TV software and/or hardware on the OLED65B7P.
I do not know what other LG TVs may have the same problem.

The fastest way to make the distortion go away without having to turn off the TV and video source - Settings/Sound/Audio Out/Digital Sound Out
Change the setting to PCM and then change the setting back to Auto and the distortion immediately stops - though it will come back again after another 10-30 minutes.

This problem would affect ANYTHING connected to the Optical Audio Out
So ANY soundbar or audio system that uses Optical input from the TV will have the same problem.

I think that if you were to leave the sound in PCM mode that the problem would probably go away too, but then you would lose all 5.1 surround sound info and instead get only left and right audio.

I will reply here when/if LG fixes the problem.
If they do not fix the problem soon, I will be returning my tv before the warranty runs out.


Jan 30, 2018
Yes an hdmi audio extractor would work for a single external hdmi source, but does not allow use of internal smart-tv apps like netflix. Then I would need an external Roku for netflix, an hdmi switch to switch multiple sources, and then the audio extractor. I hate not being able to use the builtin smarttv apps, but I may have to do this.
One additional benefit of the above roku/hdmi switch/hdmi audio extractor would be (hopefully) better lip sync - Sonos is HORRIBLE about lip sync as it adds 20-50 ms delay to sound and there are no tvs that I know of that allow delaying the video - they only allow delaying the audio and the audio is already too late.
Dec 17, 2018

My Setup:
Charter HDMI, XBOX 1S HDMI, Sony 4K HDMI - TV - Optical Out - Sonos Playbar
TV is set to the correct settings so that I am getting Dolby 5.1 and not Stereo sound, Same as for my XBOX 1S and 4K Player

Originally I thought this was a Sonos issue, but after I was referred here by our community it seems this is a LG problem! and possibly a OLED specific problem. (Don't Quote me on that)

Similar to your case it works fine until about 10-30 Min and/or from what I noticed a loud scene with music and explosions that quickly transitions into some quite dialog initiates the static/crackling sound also. It comes from the center of the Playbar I've noticed and is prone to happen sooner when the TruePlay sound is turned on via the Sonos App (If turned off it doesn't happen so quick). The Problem comes and goes, but once it comes it stays until the TV is turned off and whatever source I'm using is turned off also, but no matter what after turning everything back on in 10-30 min its starts happening again.

I went through Sonos Support also. After Numerous diagnostic checks, Customer Service Phone Calls, Audio recordings were even sent in to validate that the speaker was doing what I am describing and Sonos even replaced my Playbar thinking it was a faulty speaker, just to find out it didn't fix the problem........ what a pain in my ass if you know what I mean!

I understand you've talked with LG and they have confirmed its a known problem, but how would it be fixable? via Firmware update? or an actually replacing of hardware in the TV? Frankly I'm pissed! And This is a major problem for LG and the consumers like us in my opinion, we are the ones who are getting the shaft! we've spent thousands of dollars on these TV's & sound systems and cant even enjoy it. I hope LG works with company's like Sonos to remedy this situation, because after all most company's don't use Digital optical for there soundbars and home entertainment systems. This is hurting both company's and I hope we get a fix sooner rather then later.

I will reply here also if and when LG fixes the problem. if they don't come to a solution soon, I will be returning mine as well.

I originally thought this was just a Sonos Issue and I was wrong, its both LG & Sonos issue in my opinion and they need to work together for a fix. luckily I have never had a lip sync with my Sonos system. I understand the audio extractor idea and it could work as a fix, but I think instead of spending more money ill just return this TV.

Dec 17, 2018
Thx for the reply, is there any loss in audio quality? Will all my sources still play in 5.1 Dolby digital? and your saying that with the Extractor option that the internal apps such as Netflix and hulu etc. will also be fixed? If it lowers the quality of sound and still wont work for internal apps I wont be trying this option, because then that leads to more money, Audio extractor, HDMI Switch, and an external device such as a Roku, apple tv, etc. that all equals more money when id rather just return the tv and buy one without all this craziness. thanks for you help its much appreciated
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