Audio Delay for HDMI Connected Dolby Sources DJ_GLiTCH Posted on 2019-06-12 23:08:38 edited September 2019 OLED TVs Vote Up0Vote Down

I recently purchased a C9 OLED (firmware 03.60.04) and SL8YG soundbar (firmware main 5484640-157053), and have been experiencing large audio delays of up to two seconds when playing Dolby content from an external HDMI device through the HDMI ARC port between the TV and soundbar.

As the C9 supports HDMI 2.1, I have all of my HDMI sources connected directly to the TV. This allows me to take advantage of VRR, ALLM, etc. Whilst I understand that the SL8YG does not currently support eARC (I am hoping this will be released in a future firmware update), it does support DD+ over ARC. This allows the TV to passthrough Dolby Atmos content using DD+ rather than Dolby TrueHD over ARC to the soundbar.

The problem, however, is that only PCM and DTS are passed through the TV without introducing any audio delay. As soon as the source switches to Dolby related content (Dolby Atmos, Dolby Digital, etc.) there is a significant delay in the audio being transmitted to the soundbar. I have bought certified premium HDMI cables, which have made no difference. I have also tried every possible configuration in the TV setting menu (AV Sync Adjustment, Bypass, etc.), all of which have made no difference.

The reason why I know the TV is at fault is because all internal apps on the TV (e.g. Netflix) do not experience this issue with Dolby content. My 4K Bluray player (Sony UBP-X700) does not experience this issue either when it is connected to the HDMI in on my SL8YG - the audio and video are in perfect sync. It is only external devices that are connected through HDMI directly to the TV and have to pass audio over HDMI ARC that experience this issue. FYI, I have verified that Optical also experiences this problem.

A great test is to plug an Xbox One X into HDMI 1 on the C9 and an SL8YG (HDMI ARC) into HDMI 2 (ARC) on the C9. From the Xbox audio out settings, you can manually set PCM which works perfectly (no delay), DTS which works perfectly (no delay), but Dolby Digital or Dolby Atmos will experience significant audio delays. Further, if you leave the Xbox set to Dolby Atmos and then override the C9 'Sound Out' to be PCM rather than Passthrough, the delay is improved (as a rough guide, passthrough of Dolby encoded content would be around 1s whereas decoded to PCM would drop this to around 300ms). This highlights that there is a problem with the way that the C9 is processing Dolby content from external HDMI connected sources, which causes the audio to lag the video - something that cannot be manually fixed by any available adjustment, not that this would be a viable solution if you wish to use other advertised features of the TV such as ALLM.

I have reached out to LG support a number of times but have been unable to advance this discussion to the appropriate engineering team. Can you please pass this information on to the relevant engineers and advise on when we can expect this functionality to be fixed?



0:00 - 1:00 - LG C9 Audio Settings and Firmware Version

1:01 - 1:20 - Issue with LG C9 not being able to receive 5.1 or 7.1 uncompressed (this should work regardless of whether ARC is being used or not, as the TV can convert 7.1 uncompressed to bitstream output for ARC)

1:21 - 1:40 - Stereo Uncompressed (perfect, no noticeable audio lag)

1:41 - 2:08 - DTS Digital Surround (very good, no noticeable audio lag)

2:09 - 2:40 - Dolby Digital (poor, up to half a second audio lag)

2:41 - 3:15 - Dolby Atmos (very poor, up to a second or more of audio lag)

3:16 - 3:48 - Stereo Uncompressed (perfect, no noticeable audio lag)

dvdman

I have the same issue. When I watch ABC nightly news @6:30 PM, the audio is about one second behind. I have my C9 connected to a Denon 7.1 system.

A new firmware came out 2 days ago to download onto a usb stick. I haven’t tried it yet,  but hopefully it addresses this issue. 

DJ_GLiTCH

Dvdman, I am on the latest firmware revision (03.60.04) and still experience the issue. If you have a different firmware revision that has fixed it please let me know, but from what I’ve heard this issue is present on all LG OLED TVs. I don’t think this would be fixed unless LG specifically state the issue as being fixed in the firmware revision change log.

C9 firmware revision 03.60.04 change log below:

1. Improvement

 1) Amazon Alexa service ready. Need to download "Amazon Alexa" app from LG Contents Store. (USA, Canada, Mexico, France, Germany, Spain, United Kingdom, Austria, Ireland, Italy, Australia, India, New Zealand, Japan) (This Service will be available soon)

 2) Improving Youtube voice service

 3) Adding sound bar to Home dashboard

 4) Fixed minor bugs.

mdouglas10

Xbox One X -> (HDMI)-> Lg C9 -> (HDMI ARC)-> Hw-q70r. 
I'm having the same issue. Atmos or Dolby digital has a solid 1-2 second delay , but DTS has no delay.

Would love to get Dolby Digital/Atmos/True HD working for hdmi sources via ARC/EARC... Internal apps work just fine with no delay.

dvdman

I have the same delay issue on the latest .04 firmware. 

DJ_GLiTCH

Can anyone from LG please comment on this issue?

I'd be interested to know whether anyone with an eARC capable soundbar or AV receiver experiences this issue as well.

mdouglas10

Would also appreciate an update on this. Seems like such a basic thing that should just work...

JamalofLG

I will get this escalated for review.

JamalofLG

Can you try the setup below and advise if the problem continues?

Xbox One X(MS Xbox) -- <HDMI>-- SL8YG(LG Sound Bar) -- <HDMI>--- C9(LG TV)

mdouglas10

Hi Jamal,

I own the Samsung HW-Q70R, and when I do 

Xbox One X(MS Xbox) -- <HDMI>-- Samsung HW-Q70R, -- <HDMI>--- C9(LG TV)

I get NO Dolby audio delay. The issue only applies when I plug the xbox into the TV (Which I need for VRR support etc.) and use either ARC or EARC

rogierbl

Hi, 

I have exact same issue with my new LG 55C9PHA OLED I recently bought.

I have an Xbox One X connected to HDMI 1 on TV and a Onkyo TX-NR686 receiver connected to HDMI 2 (eARC) for the pass trough of Dolby Atmos from Xbox One X to my Onkyo.

And I have a Nvidia Shield connected to HDMI3 on TV. 

All 3 cables to TV are HDMI 2.1 Belkin cables.

With the Nvidia I have no delay issues with Dolby Atmos. I use my Nvidia with Plex

But with Xbox One X set on bitstream and Dolby Atmos (with the Xbox app) I have a good second or so delay, the sound is behind with picture.

This is with games or with my cable box connect on Xbox, Plex on Xbox and Netflix app on Xbox.

If I change the sound settings on Xbox to DTS I have no delays with sound and even with Dolby Digital there is almost no delay.

If I use the Netflix app from the TV LG store I also have no delays with Dolby Vision/Atmos content.

And finally if I use my Onkyo as central hub with all my devices like Xbox, Shield, etc. connected to my receiver and the HDMI output to my LG HDMI 2 I have no delays in any sound with Dolby Atmos or anything else.

But I just wanted to use the eARC for the VRR and Auto Low Lantency mode and the Dolby Vision support.

So I really hope there will be a fix with firmware or anything soon so I can truly enjoy this great TV!

Regards,
Rogier

DJ_GLiTCH

Jamal, I stated in my third paragraph that routing through the soundbar eliminated the audio delay, however, this prevents me from taking advantage of ALLM, VRR, etc, which are available only through direct HDMI inputs on the TV. Please refer below:

"My 4K Bluray player (Sony UBP-X700) does not experience this issue either when it is connected to the HDMI in on my SL8YG - the audio and video are in perfect sync. It is only external devices that are connected through HDMI directly to the TV and have to pass audio over HDMI ARC that experience this issue. FYI, I have verified that Optical also experiences this problem."

Tomcup

I also experience audio delay with TV set to eARC and Xbox One X set to bitstream Atmos --> 77"C9 OLED (03.60.04) --> Denon 6500H.   I will note, that if you research this issue related to Xbox, it is possible it is the Xbox upsampling to Atmos causing the delay vs the TV itself.  

mdouglas10

Considering there is no delay when connected directly to a soundbar , it is not the xbox at fault. Dolby digital also features the same delay.

JamalofLG

Thanks for the responses. I have escalated the responses to Engineering for further review.  

DJ_GLiTCH

Tomcup, I have to agree with mdouglas10 on this one - if you connect the Xbox straight to your soundbar or AV receiver, there is no dolby delay (whether it be Dolby Digital or Dolby Atmos). The issue only appears when the TV is required to passthrough the Dolby signal from an external device through the ARC/eARC channel on HDMI 2 to your soundbar or AV receiver.

Thanks Jamal. If you could please provide us with updates as you receive them it would be greatly appreciated.