LG UHD TV digital sound out popping noise problem

[Krash01]

Dear Readers,

I've a strange issue that I've been struggling for a week. I bought an LG43UJ634V UHD TV and an LG LHB645N Home Theater in a Box system.
I use HDMI ARC to connect the audio from the TV to receiver. LG has an option to chose between PCM or Auto at the Digital output settings.

If I use the PCM option everything sounds great, but I don't have 5.1, only 2.1.
And here comes the problem. When I choose Auto, 5.1 is on, sounds great but I have occasional popping noise (like when play something on an old LP player) it happens random, but for example during a film, it is very annoying. It happens with YouTube, Netflix, DLNA streaming, external devices, so the content doesn't matter. I think I've tried everything. I tested it with different HDMI cables, optical cable, but still have the problem. I tested it with a sound bar as well, the problem is the same.
When I play content from the receiver, there is no problem, the sound is wonderful, no popping. Also, the TVs speakers are okay.

I don't think it is a hardware issue, because the TV's sound is OK, the home theater's sound is OK, the problem only happens when I want to use the digital output of the TV (either HDMI ARC or Optical) with auto setting.
I called LG as well, the rep. said the she will pass this info to the technical team.

Do you have any idea, that it can be solved, or I need to wait for a software update?

[Krash01]

Today LG replaced the main board in my TV, and as I had expected earlier nothing has changed, so it is definitely a software issue :(.

[Krash01]

Okay, I have searching on the net for a week, and found some posts about this problem (not specifically with LG TVs). All solutions said, that set digital output mode to PCM.  It works for me as well, but in that case no Dolby Digital 5.1 . Also, an LG tech called me, he wants to replace the main board of the TV, but I don't think that will help (he isn't sure as well). If that is a hardware issue, than I should get this problem via PCM setting as well (moreover the sound is digital, so the two options are sound or no sound, digital sound can't have interference, popping noise or things like that). So assume this is a transcoding issue, and it has to be the software.

Anyone experiencing a thing like this?

[Hunter_S]

How old are are your Receiver and Sound Bar? In case it helps, I had an older Pioneer receiver that was otherwise fine, but two issues appeared when it was used with the Optical out on a new 55LJ5500 (WebOS 3.5) set:

1. The TV attempts to passthrough Dolby Digital Plus (DD+) content as-is. The can cause issues for older receivers that do not explicitly support DD+. Content-wise, DD+ is served up by some broadcast stations and some streaming platforms like Netflix. On my old receiver, this caused momentary and random audio drop-outs, but I imagine this could manifest itself in different ways. The same content seemed to play fine on a receiver that supports DD+.

2. The TV transcodes AAC audio to Dolby Digital. At least on my set, WebOS does a very poor job at this. On my older receiver, the resulting audio also caused momentary audio drop-outs. On a newer receiver it doesn't drop-out, but it still sounds bad. Content-wise, most YouTube content uses AAC.

[Markl]

I'm having the same problem but haven't found PCM mode to correct it only reduce it. I have a new LG 55UJ6540 and a new Vizio 5.1 soundbar. I even installed a high end HDMI to replace the one that came with the Vizio. I notice this in particular  on Direct TV when watching Cinemax.

[Hunter_S]

I guess I had thought that my issue was limited to AAC audio, but during the past several days, I've been noticing popping \ garbled \ compressed sound from both ATSC broadcast and DLNA content with DD 5.1 over HDMI ARC. A side-by-side comparison to a PS3 made it pretty clear that the source of the issue is the TV set. So I guess I'm now noticing the same exact issue that you are, Krash.

I guess the decision now is whether to return the set, live with it, or hope that this is on LG's radar and repairable with a firmware update. I also agree that any mainboard replacement isn't like to solve the issue unless there has actually been a hardware revision.

 

 

[Krash01]

Okay, a tech from LG was at my place on Monday, he wanted to replace the main board, but the one that LG ordered for him, was for a different model (no comment...), so he is going to come back next Monday.

Anyway, he observed the problem, and he also thinks that is a software related issue, but first he has to replace the main board, to exclude the hardware problem.

My LG LHB645  home cinema set was released in mid 2015, but it is still in production (I bought it two weeks ago, so it is new), but the last SW update was in 2016. 

My TV is a very new model, with a very fresh software update (not even a month old), so he thinks that TV "speaks" to the receiver too fast, the two softwares are not totally compatible. If it is really a software issue, than it's a bigger problem, for us. If not enough customers  are complaining about it, or LG doesn't experience this issue in the factory, than there isn't so much hope that they are going to fix it. Actually, I'm very angry, because I specifically bought the LG home cinema to avoid compatibility issues....

He suggested to return the home cinema, and try to find a 2017 model, but I've just realized every company started to offer just soundbars, and no HTIB 5.1 systems (of course I can buy speakers and a receiver separately, but that would be really expensive...).

[Hunter_S]

Interesting. Thanks for the update.

[GurnaamSingh88]

Hi,

I experienced the same popping issue yesterday, I bought the 55inch 635 model and the same surround sound. really bad popping sound and I too bought the same branded surround sound to avoid issues.

[Krash01]

Me too :(.

So I'm not the only one....it's driving me nuts, I hope that LG is gonna fix that soon.

[Krash01]

Actually I found an other interesting thing. My TV doesn't play DTS sound (according to it's specs, it should know it). I've tried a sample video with DTS through the TV->no sound at all, through my receiver-> it is perfect.

Do you have a problem like this? Probably this digital audio decoding is a total mess in that software....

[GurnaamSingh88]

You know what, it was bugging me why some of the videos I was streaming from my pc wasn't working (audio not supported, or no sound at all) and this makes sense now. I thought "everything" was compatible with this tv but turns out, some of the 4k content out there is not compatible. Beginning to think I should have just paid the little extra for the Sony...

Do you know whats happening with the popping? mine I noticed is when I pause something that I am streaming.

[Hunter_S]

On 12/6/2017 at 3:15 PM, Krash01 said:

Actually I found an other interesting thing. My TV doesn't play DTS sound (according to it's specs, it should know it). I've tried a sample video with DTS through the TV->no sound at all, through my receiver-> it is perfect.

Do you have a problem like this? Probably this digital audio decoding is a total mess in that software....

No, Krash, I do not have that problem. DTS plays fine for me through the internal speakers. I tested this with MKV files containing DTS streams over DLNA, and verified that the TV was indeed receiving DTS sound by opening the 'info' panel during playback. (I also needed to change the sound out option to Internal Speaker, but I'll assume you did that too. 😀)

13 hours ago, GurnaamSingh88 said:

You know what, it was bugging me why some of the videos I was streaming from my pc wasn't working (audio not supported, or no sound at all) and this makes sense now. I thought "everything" was compatible with this tv but turns out, some of the 4k content out there is not compatible. Beginning to think I should have just paid the little extra for the Sony...

Do you know whats happening with the popping? mine I noticed is when I pause something that I am streaming.

Gurnaam, I was thinking the same thing about compatibility (and why not? the published WebOS 3.5 compatibility listing is pretty long), and I had high hopes. There are some fairly new video codecs supported, which is why I was so surprised that my set was having difficulty with long-standard audio codecs like AC-3/DD and AAC.

Do I know what's happening? No, not for certain. To be honest, the specific issue that you are noticing seems a little bit different from mine: for you, it occurs during pause, and some sound isn't playing at all. I would be interested to hear about the specific file types you are trying to play and what the rest of your setup looks like (optical or HDMI? Receiver or Soundbar? Age of other components? etc...). On my set, I just notice poor quality audio during playback from certain AAC and DD 5.1 sources that I know are fine.

[Shermann]

Hello, was there ever any resolution to this? We are having the same issue on the HDMI arc. We started using optical for audio. But now we can’t tun everything on with one remote. We have a 2017 model. Very frustrating for such an expensive tv.

[GurnaamSingh88]

No thing yet, keep getting the "app will restart because the memory low" its terrible.

[Shermann]

17 hours ago, GurnaamSingh88 said:

No thing yet, keep getting the "app will restart because the memory low" its terrible.

I keep getting that too!!

[Zsolt Jenei]

I have the same also with UJ model. Did you report to LG? Anyone got answer from their support? 

[Krash01]

Hi Zsolt,

No solution unfortunately, I've tried every possible way, but LG couldn't solve this problem. Now I'm watching films through my home theater, not the TV.

LG said the TVs software and HT's software is not compatible (the tv "speaking" too fast to the HT).

[Zsolt Jenei]

I'm using a Logitech Z906 5.1 system with the same issues. Can you help me how can i report this?

Their answer is ridiculous, there are standards in audio digital transmission, they have to fix this.

[Zsolt Jenei]

I could live with having my PS4 not going through the TV, but I'm definitely irritated that it is popping with the TV's apps like Netflix and Plex.

[Krash01]

Try to call LG Hungary and report it. They asked me to record the sound and send the video to them, than they will forward it to the factory, but I don't think it'll help. Actually I'm tired of it, they were at my house 3 times (replaced the motherboard etc.), no solution. The issue is definitely in the SW, but I don't think they'll revise it.