• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Noisy digital audio on LG TVs

elvisizer

Active Member
Joined
Sep 16, 2018
Messages
255
Likes
191
I had dropouts with an LG CX optical out to a Topping D90se dac, though the same CX output is accepted no problem by a mytek dac. Both of those are ESS based, Sabre 9028 Pro in the mytek, 9038 Pro in the topping.
Using HDMI eARC with a 2nd CX output to a denon AVR has had no issues for me, fwiw the denon has an AKM dac.
 

wyup

Active Member
Joined
Mar 29, 2018
Messages
177
Likes
71
Location
Bilbao, Spain
Dear audio science enthusiasts,

I recently got one of those popular LG C1 TVs. Since I only have a stereo system, but several HDMI sources plus using the TV's apps, I went the easiest audio route for my setup:
(source) -> TV -> optical out (PCM) -> DAC -> analog Preamp
As I realized only after my purchase, the optical out of LG TVs seems to be quite terrible (noisy) across models and LG seems to not care about it. Most clearly it's stated in an FAQ by JDS Labs, who measured SINAD of 81db from one LG TV. Quite a few people complain about stuttering audio as well, coming from some DAC's jitter handling not "expecting" such a terrible source signal. Now my DAC doesn't have that problem*, but I'm still curious if using an HDMI audio extractor may yield a better signal.
So my question is if anyone has tested or seen this measured for LG TVs in particular: optical out vs extracted from ARC HDMI?
I've seen at least one report where people have tried the extractor route without solving their stuttering audio problem, which leads to the question if LG has only messed up the optical output or digital audio output in general.

Here's a thread from AV Forums about the topic.

* DAC is a Lake People RS-06, which the manufacturer claims has a resampling and re-clocking implementation that "almost completely rejects jitter". I have no idea to which % this is marketing mumbo jumbo, but at least I get no interruptions to audio.
My new Samsung S95B tv causes stuttering on optical through an SMSL SU-8 dac, on both DVB and USB media. It sounds ok through my Onkyo A-9010 stereo amplifier toslink input with the same cable, so I guess the SMSL is more sensitive to jitter.

I also gave a thought to a (e)ARC HDMI extractor, there are some with I2S output for 50$ on AliExpress, but guess how much jitter they yield.

My S95B premium tv also resamples 44.1 KHz content to a constant 48 KHz, so I'd rather use a streamer for native samplerate and less jitter playback.

To me the best scenario with a Sony or Android TV based one is connect the DAC by usb. Usb has better jitter correction. Or a new dac with great toslink jitter rejection. Most recent ones by Topping or SMSL have very low jitter and they have a jitter sensitivity setting. But if the tv does 48 KHz resampling it is useless, you need a streamer for CD content.
 
Last edited:

rossfoo

New Member
Joined
Dec 2, 2022
Messages
2
Likes
0
I'm in the same boat now with an LG C2 and a SMSL M500.

@JunkHippo or anyone else. Did you end up with an extractor of some sort? Do you guys think there's any point in keeping the SMSL (vs option 1 below)?

I'm a total beginner here so any advice would be much appreciated. As far as I've read about this issue the options are:
  1. Swap SMSL
    1. With an AVR
    2. Wireless stream (e.g. bluesound node)
  2. Extractor (that doesn't degrade quality beyond the original issue...)
  3. Update SMSL firmware and pray
Last question: If I'm going to use an extractor does anyone know if eARC can be used essentially as an "audio out" from the TV to the extractor?
 
OP
JunkHippo

JunkHippo

Member
Joined
Feb 8, 2021
Messages
17
Likes
19
I can share that I have an eARC extractor now and go via the Toslink output to my DAC. For your last question @rossfoo I can confirm, basically an eARC HDMI port sends the digital audio and the extractor takes that and puts it out via coax or Toslink to your DAC.
However since I didn’t have sound dropouts or similar issues that would be easily identifiable by ear, I can‘t say for sure if anything changed. Very subjectively I would say yes, to the better, but probably that’s confirmation bias. Anyway the extractor was cheap, is easily hidden behind the TV, works without issues, and is likely not worse than the compromised optical out of the TV. So I‘ll leave it installed.
If I ever get a DAC with two optical inputs (hunting for 2nd hand Benchmark DAC3), I might try switching back and forth between TV and extractor, to listen for differences.
Currently that would involve plugging cables in and out, making for a less immediate comparison.
 

james57

Member
Joined
May 10, 2022
Messages
83
Likes
36
Kind of the same setup LG G1 to oppo(preamp dac) to amp.. I have tried both optical and HDMI arc. I must be tone death, see no difference in audio quality and have not experienced drops. But on the functionality side its different. When you use hdmi arc you can control the vol and the lg remote is a piece of sh.. hence why I prefer using optical and using the oppo remote for vol ctrl. Also opti is always linked. HDMI arc seems to need a new handshake each power on, which is kind of anyoying. I am running a 2.1 setup so no format difference between both path, I know optical is more restrictive for ATmos and multi channels, think over 5.1 but not my case.
 
Last edited:

rossfoo

New Member
Joined
Dec 2, 2022
Messages
2
Likes
0
Kind of the same setup LG G1 to oppo(preamp dac) to amp.. I have tried both optical and HDMI arc. I must be tone death, see no difference in audio quality and have not experienced drops. But on the functionality side its different. When you use hdmi arc you can control the vol and the lg remote is a piece of sh.. hence why I prefer using optical and using the oppo remote for vol ctrl. Also opti is always linked. HDMI arc seems to need a new handshake each power on, which is kind of anyoying. I am running a 2.1 setup so no format difference between both path, I know optical is more restrictive for ATmos and multi channels, think over 5.1 but not my case.

Your Oppo unit doesn't have an HDMI in does it? What do you use to convert from HDMI out?
 

james57

Member
Joined
May 10, 2022
Messages
83
Likes
36
Your Oppo unit doesn't have an HDMI in does it? What do you use to convert from HDMI out?
The oppo 105 has one hdmi in but the lg only has several hdmi in no out, this is why I am sending the audio via hdmi arc in lg and hdmi out arc oppo. Hope this clarifies. I am currently running optical for ease of use but both works fine.
 

ElNino

Addicted to Fun and Learning
Joined
Sep 26, 2019
Messages
557
Likes
722
I deleted an earlier post because I misread JDS Labs' website, but I'm still confused by their measurements. It's clear they were using a 24-bit test signal, but the LG optical output is locked at 48kHz/16-bit depth (see the manual). So you expect to see some quantization artifacts with a 24-bit input signal. They don't say what input sampling rate they're using, but all of the artifacts are about -90dB down, which looks to me like some combination of quantization and mid-quality software resampling.

I don't think the data supports the conclusion they're giving that there's anything actually wrong with the data on the optical out, beyond a high level of jitter that the ESS receiver can't cope with. (Maybe there's more data on a forum somewhere?)

I've never had an issue with my LG TV's optical out and several DACs, but I also haven't tried it with an ESS DAC.
 

james57

Member
Joined
May 10, 2022
Messages
83
Likes
36
,
I deleted an earlier post because I misread JDS Labs' website, but I'm still confused by their measurements. It's clear they were using a 24-bit test signal, but the LG optical output is locked at 48kHz/16-bit depth (see the manual). So you expect to see some quantization artifacts with a 24-bit input signal. They don't say what input sampling rate they're using, but all of the artifacts are about -90dB down, which looks to me like some combination of quantization and mid-quality software resampling.

I don't think the data supports the conclusion they're giving that there's anything actually wrong with the data on the optical out, beyond a high level of jitter that the ESS receiver can't cope with. (Maybe there's more data on a forum somewhere?)

I've never had an issue with my LG TV's optical out and several DACs, but I also haven't tried it with an ESS DAC.
the 105 uses the es9018, no issue here
 

Rottmannash

Major Contributor
Forum Donor
Joined
Nov 11, 2020
Messages
2,957
Likes
2,590
Location
Nashville
I deleted an earlier post because I misread JDS Labs' website, but I'm still confused by their measurements. It's clear they were using a 24-bit test signal, but the LG optical output is locked at 48kHz/16-bit depth (see the manual). So you expect to see some quantization artifacts with a 24-bit input signal. They don't say what input sampling rate they're using, but all of the artifacts are about -90dB down, which looks to me like some combination of quantization and mid-quality software resampling.

I don't think the data supports the conclusion they're giving that there's anything actually wrong with the data on the optical out, beyond a high level of jitter that the ESS receiver can't cope with. (Maybe there's more data on a forum somewhere?)

I've never had an issue with my LG TV's optical out and several DACs, but I also haven't tried it with an ESS DAC.
I've had no issue with my LG C9 and the Topping D90 SE.
 

jasonhanjk

Active Member
Joined
Mar 24, 2019
Messages
249
Likes
178
I have an LG TV here converts my 24 bit file into 16 bit output. Same goes to Samsung. :facepalm:
 

MontyGibbon

New Member
Joined
Jun 5, 2019
Messages
4
Likes
1
Hiya. Can I interpose to ask a question?
The gear in question is:

- LG OLED65C8PLA telly
> Optical cable (can't remember brand)
> Topping D70 DAC

The circumstances are:

My D70 died a couple of years or so ago. Fuses checked but, it wouldn't power on.

In the run up to that sad event, there'd been an increasing number of pops/drop outs but, only when using the D70 to process the telly signal via an optical cable.

I put the D70 demise down to a Topping QC issue. That was along time ago and, I'd not given it any thought recently ~ 'till bumping into this thread.

My question ~ could the D70 failure have arisen from a problem orginating in the LG optical implementation?

Just curious; I'm well through the bereavement period. That said, 'it' did influence my decision not to buy anymore Topping products.
 

silverfalcon

New Member
Joined
Aug 16, 2023
Messages
3
Likes
0
Hey, I ordered the bluesound a bit later when I thought, because I contacted the Genelec support (the speakers with which I had the problem). They are still looking into it, and so I ordered it because I wanted it fixed this week.

I'm glad that I can say that it totally fixed my problems. I needed to disable the "Audio clock trim" function, but after that everything was perfect.

Furthermore, I would still like to know if these cheap adapters do the job too. Did you already get one @JunkHippo?
Hi @lennyanders I wanted to know how you like your Bluesound NODE setup? I was planning on getting one myself to pair with the LG G3. I was considering using the LG G3's eArc HDMI as input into the Bluesound NODE. Are you using the Optical out from TV? Would appreciate your inputs
 

lennyanders

Member
Joined
Oct 16, 2022
Messages
43
Likes
37
Location
Germany
Hi @lennyanders I wanted to know how you like your Bluesound NODE setup? I was planning on getting one myself to pair with the LG G3. I was considering using the LG G3's eArc HDMI as input into the Bluesound NODE. Are you using the Optical out from TV? Would appreciate your inputs
I specifically got it because I had audible problems with the optical out and I wanted to use eARC, which I do now. I actually still have them sometimes, but very rarely and only with the YouTube app, I think.

I basically wanted a device with eARC in for TV, optical or coaxial in for my CD-Player and coaxial out for my monitors, so it would all stay digital. If you have other requirements, there is probably a cheaper device that can all do you need. I think 600€ is a bit much for what it does for, so I would switch when I find another device.

In another thread a device was mentioned that could basically do it for, for just ~30€, but it lacks a digital output and RCA is only rated at 85 dbs THD+N (not tested yet, but smsl is usually pretty accurate with their specs). https://audiosciencereview.com/forum/index.php?threads/hdmi-and-dacs-not-evolving.38838/post-1680256

So generally I'm pretty happy, but I'm unhappy with the state of existing solutions, you could say.
 

pablolie

Major Contributor
Forum Donor
Joined
Jul 8, 2021
Messages
1,947
Likes
3,193
Location
bay area, ca
Weird. Is some cost cutting newer TVs? My trusty 14 year old Samsung LED's optical audio out is great.
 

lennyanders

Member
Joined
Oct 16, 2022
Messages
43
Likes
37
Location
Germany
Weird. Is some cost cutting newer TVs? My trusty 14 year old Samsung LED's optical audio out is great.
I read that audio outputs on TV are generally pretty bad, and you usually want to get the audio from the HDMI devices you connect to the TV, like with an AV receiver. I don't know if it was better some years ago. I also read that LG has more problems than other TVs.

Generally, these weird problems like mine don't happen much, I think. You have to connect just the wrong devices together to get these, many devices you connect to the optical out probably work just fine, some even have options to work better with TVs. JDS Labs did some research, I think.

Don't take what I write here too serious, though, I just read some stuff on the internet myself.
 

pablolie

Major Contributor
Forum Donor
Joined
Jul 8, 2021
Messages
1,947
Likes
3,193
Location
bay area, ca
I read that audio outputs on TV are generally pretty bad, and you usually want to get the audio from the HDMI devices you connect to the TV, like with an AV receiver. I don't know if it was better some years ago. I also read that LG has more problems than other TVs.

Generally, these weird problems like mine don't happen much, I think. You have to connect just the wrong devices together to get these, many devices you connect to the optical out probably work just fine, some even have options to work better with TVs. JDS Labs did some research, I think.

Don't take what I write here too serious, though, I just read some stuff on the internet myself.
I totally believe your experience. My TV clearly.is old.and doesnt have the ARC stuff, hence I just idly wonder if more care went into the Toslink out before ARC was a widely adopted feature.
 
Last edited:

silverfalcon

New Member
Joined
Aug 16, 2023
Messages
3
Likes
0
I specifically got it because I had audible problems with the optical out and I wanted to use eARC, which I do now. I actually still have them sometimes, but very rarely and only with the YouTube app, I think.

I basically wanted a device with eARC in for TV, optical or coaxial in for my CD-Player and coaxial out for my monitors, so it would all stay digital. If you have other requirements, there is probably a cheaper device that can all do you need. I think 600€ is a bit much for what it does for, so I would switch when I find another device.

In another thread a device was mentioned that could basically do it for, for just ~30€, but it lacks a digital output and RCA is only rated at 85 dbs THD+N (not tested yet, but smsl is usually pretty accurate with their specs). https://audiosciencereview.com/forum/index.php?threads/hdmi-and-dacs-not-evolving.38838/post-1680256

So generally I'm pretty happy, but I'm unhappy with the state of existing solutions, you could say.
My required solution is quite similar to yours. These days TV UIs are very good and I want to be able to play music videos and content from my TV but with higher resolution. The Bluesound seems to be the perfect solution especially since Optical does not seem that reliable from the LG tvs anyways and hopefully the eARC works reliably in terms of dropouts and in terms of sampling rate from the TV/source. Also, I was looking for a streaming player as well and this one of the very few players that seems to support HDMI eArc. Do you also have an LG? I am hoping it works reliably over HDMI eARC but we will see
 

wyup

Active Member
Joined
Mar 29, 2018
Messages
177
Likes
71
Location
Bilbao, Spain
The Bluesound seems to be the perfect solution especially since Optical does not seem that reliable from the LG tvs anyways and hopefully the eARC works reliably in terms of dropouts and in terms of sampling rate from the TV/source.
On what do you base that eARC from TV is more reliable than optical? Both are clocked fron the same device, the tv. I tested both, and the tv resamples 44.1Khz to 48KHz the same, and in my case It had dropouts aswell on HDMI arc. It all depends on the dac's ability to reduce jitter.
My solution was using a Raspberry Pi with a spdif transport with good clocks as a streamer for A/V. It respects original samplerate and sounds better.
 
Top Bottom