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Question LG 55UK6300YVB can't play 5.1 sound

Krishi

Novice Member
Hello, I have a simple home entertainment kit from Samsung model: ht-e453hk (it's a DVD player with 5.1 speakers that has also AUX and S/PDIF input) which was connected via optic cable to my PC. that worked well and I saw content with surround sound 5.1 no problem.
Now I got the LG tv and tried to connect it to the Samsung player with the optic cable and put some movies on the NETFLIX app on the TV to see if it works (movies with 5.1 sound). I can hear the speakers work but only the front, not the back. tried to check every option available on the tv settings and the Samsung kit settings and can't make it work. Either the TV can't send 5.1 sound through Optic cable or the Samsung kit can't receive it (Although it did work with the PC). Thought maybe to change the setting on the service menu on the tv so that it would pass-through the DTS (maybe it set only on PCM as i saw on one youtube clip) but couldn't get to open the service menu for this model.
Any help would be appreciated
 

SeeMoreDigital

Well-known Member
Your TV should be able to send multi-channel Dolby Digital audio as a bit-stream via optical SPDIF to your Samsung, just fine.

When playing Netflix content visit the TV's 'Sound' settings and under 'Sound Out' select 'Audio Out (optical/HDMI ARC)' and under 'Digital Sound Out' select 'Auto' (this is important and should not need to be changed again).

Then while the Netflix content is playing, press the 'OK' button on the remote control, press the 'up' arrow button. And in the top right corner of the screen you should see the 'AUDIO & SUBTITLES' options. Press 'OK' and navigate down through the audio options until you find the '5.1' one you want... But I suspect you know this bit already ;)
 

chunkeyninja

Standard Member
Yep definitely want to avoid PCM and set to auto as above as this will force it into stereo format. The TV does support full 5.1 pass through so likely a formatting issue. One thing you can try is going into AV Sync Adjust in the sound options, enable it and leave the delay at -+0ms and enable the Bypass option if you can. This stops the TV doing any post processing on the audio so could resolve this issue.
 

Krishi

Novice Member
Your TV should be able to send multi-channel Dolby Digital audio as a bit-stream via optical SPDIF to your Samsung, just fine.

When playing Netflix content visit the TV's 'Sound' settings and under 'Sound Out' select 'Audio Out (optical/HDMI ARC)' and under 'Digital Sound Out' select 'Auto' (this is important and should not need to be changed again).

Then while the Netflix content is playing, press the 'OK' button on the remote control, press the 'up' arrow button. And in the top right corner of the screen you should see the 'AUDIO & SUBTITLES' options. Press 'OK' and navigate down through the audio options until you find the '5.1' one you want... But I suspect you know this bit already ;)

Yep definitely want to avoid PCM and set to auto as above as this will force it into stereo format. The TV does support full 5.1 pass through so likely a formatting issue. One thing you can try is going into AV Sync Adjust in the sound options, enable it and leave the delay at -+0ms and enable the Bypass option if you can. This stops the TV doing any post processing on the audio so could resolve this issue.

sorry guys, both suggestions didn't work
 

Foster1984

Well-known Member
Now I got the LG tv and tried to connect it to the Samsung player with the optic cable and put some movies on the NETFLIX app on the TV to see if it works (movies with 5.1 sound). I can hear the speakers work but only the front, not the back.

Are all 3 front speakers playing sound? Or only the front left and right?
 

Foster1984

Well-known Member
It would seem then that either you don't have the TV set up to send 5.1, or your home theatre system is down-mixing the signal to stereo.
 

Krishi

Novice Member
It would seem then that either you don't have the TV set up to send 5.1, or your home theatre system is down-mixing the signal to stereo.
well my home theater system plays 5.1 sound when connected to my PC via Optic cable.
Plus I found out that the HDMI port on my home theater system is also ARC so I connected it to the TV via HDMI cable and it worked, I could hear 5.1 surround sound. Still I prefer to connect it with Optic cable and don't understand why it's not working. I need all the HDMI ports on my TV for other devices, plus I have an Optic switch with a remote (didn't connect it yet) so it'll be easier for me to switch between PC and TV sound output.
 

Foster1984

Well-known Member
well my home theater system plays 5.1 sound when connected to my PC via Optic cable.
Plus I found out that the HDMI port on my home theater system is also ARC so I connected it to the TV via HDMI cable and it worked, I could hear 5.1 surround sound. Still I prefer to connect it with Optic cable and don't understand why it's not working. I need all the HDMI ports on my TV for other devices, plus I have an Optic switch with a remote (didn't connect it yet) so it'll be easier for me to switch between PC and TV sound output.

OK, if you can get 5.1 via the PC, that would suggest it is the TV not sending a 5.1 signal.

Have you double checked the TVs sound settings for optical?
 

Krishi

Novice Member
OK, if you can get 5.1 via the PC, that would suggest it is the TV not sending a 5.1 signal.

Have you double checked the TVs sound settings for optical?
Yes I checked and tried every available option.
But the TV did send 5.1 signal via HDMI, why it didn't send so also via optic cable?
 

Foster1984

Well-known Member
Yes I checked and tried every available option.
But the TV did send 5.1 signal via HDMI, why it didn't send so also via optic cable?

Apparently LG TVs only pass 2 channel PCM via optical by default; with no option to change this in the settings.

There is however a workaround via the service menu:

 

Krishi

Novice Member
Apparently LG TVs only pass 2 channel PCM via optical by default; with no option to change this in the settings.

There is however a workaround via the service menu:


Yes I saw this video, unfortunately I couldn't access the service menu on my LG model
 

SeeMoreDigital

Well-known Member
Media streaming services such as Netflix and Amazon don't offer lossless multi-channel PCM audio, they offer lossy compressed multi-channel Dolby Digital or Dolby Digital Plus bit-stream audio.

When such services are accessed via the TV's internal apps the Dolby Digital or Dolby Digital Plus bit-stream audio can be TV can be passed via HDMI or SPDIF without having to access the service menu.

Indeed, I'm sending a multi-channel Dolby Digital bit-stream via SPDIF to my Onkyo AVR right now without any issues at all...
 

SeeMoreDigital

Well-known Member
Apparently LG TVs only pass 2 channel PCM via optical by default; with no option to change this in the settings.
All televisions are only able to send a 2 channel PCM stream via SPDIF due to bandwidth limitations.

Only lossy compressed 'bit-streamed' audio formats such as Dolby Digital or DTS can pass multi-channel audio via SPDIF.
 

Foster1984

Well-known Member
All televisions are only able to send a 2 channel PCM stream via SPDIF due to bandwidth limitations.

Only lossy compressed 'bit-streamed' audio formats such as Dolby Digital or DTS can pass multi-channel audio via SPDIF.

Yeah, not sure why I put PCM, I'm well aware of SPDIF's limitations.

Can the LG's send standard DD & DTS 5.1 via SPDIF then?

I'd assume they can, as every TV I have owned previously has, including an older non-smart LG. But can't see it in my current LG's menu (though I'm not connected to any external sound systems ATM) and when I googled it to help the OP, I could only find articles regarding it needing to be unlocked via service menu.
 

SeeMoreDigital

Well-known Member
Can the LG's send standard DD & DTS 5.1 via SPDIF then?
As I mentioned previously, mine can. Via the TV's inbuilt apps and DVB-T2/S2 tuners. And when playing media files (encoded with multi-channel Dolby Digital, DTS and even AAC (which is transcoded to Dolby Digital)) from USB or network connected HDD's via the TV's media player.

My particular humble LG television can't however (by default) 'pass-through' Dolby Digital or DTS bit-streams from HDMI directly connected devices (much like in the video).


Cheers
 

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