Noisy digital audio on LG TVs

[wyup]

The fact that it's been going on for multiple years and effects multiple models, suggest its not something that can be fixed with a settings update. Its most likely hardware related, or the manufactures just don't care.

How come manufacturer doesn't care? Audio out is basic functionality!
Hardware related? Are we going backwards or what? I say my 2009 Samsung tv, half the price as last, sounds ok through optical.

 

[DLS79]

How come manufacturer doesn't care? Audio out is basic functionality!
Hardware related? Are we going backwards or what? I say my 2009 Samsung tv, half the price as last, sounds ok through optical.

there's a difference between caring that it works with a run of the mill AVRs or soundbars (they all sell their own), and caring that it works with a high end/SOTA DAC chip that strictly adheres to standards and protocols.

In other words if 99% of their customers just use the built in speakers, or a house brand AVR or soundbar (that just works), they aren't going to care about the 1% (most likely well less than 1%) of customers using 3rdy party products!

 

[wyup]

there's a difference between caring that it works with a run of the mill AVRs or soundbars (they all sell their own), and caring that it works with a high end/SOTA DAC chip that strictly adheres to standards and protocols.

In other words if 99% of their customers just use the built in speakers, or a house brand AVR or soundbar (that just works), they aren't going to care about the 1% (most likely well less than 1%) of customers using 3rdy party products!

Excuse me. SOTA dac chip? It is 300€. Optical is universally compatible. Not invented for their soundbars.
Am I 1%? I'm no fool to use a soundbar. I was born in the seventies, the golden era of hifi. I put my money where it matters. It doesnt take much to make it right. Oled technology much more complex.

 

[DLS79]

Excuse me. SOTA dac chip?

are you asking me what SOTA stands for?

Optical is universally compatible. Not invented for their soundbars.

It is and it isn't. it's protocol that's has standards. If a manufacture is being lackadaisical about following them, they could have issues with other manufactures who adhere to the standards more strictly.

S/PDIF - Wikipedia

en.wikipedia.org

For example you are supposed to specify the accuracy of the clock. If you says its 50ppm but the dac starts seeing 60, 75 or 100ppm what do you think its going to do?

Am I 1%?

If you are a member of this site you most likely are. the other 99% are the people going of the recommendations of the customer service rep at best buy.

 

[Galliardist]

Excuse me. SOTA dac chip? It is 300€. Optical is universally compatible. Not invented for their soundbars.
Am I 1%? I'm no fool to use a soundbar. I was born in the seventies, the golden era of hifi. I put my money where it matters. It doesnt take much to make it right. Oled technology much more complex.

What difference does the DAC chip make to the optical transmission process? There's a transmitter and a receiver. They should both work to standard, whether what's after the receiver is an overpriced uberDAC product or a smart speaker.

 

[Roland68]

Excuse me. SOTA dac chip? It is 300€. Optical is universally compatible. Not invented for their soundbars.
Am I 1%? I'm no fool to use a soundbar. I was born in the seventies, the golden era of hifi. I put my money where it matters. It doesnt take much to make it right. Oled technology much more complex.

The problem of 2 major TV manufacturers in connection with coaxial and optical digital stereo sound output in connection with 2 channel DACs has existed for a long time and is clearly a problem for these two TV manufacturers. Especially with these two manufacturers you will find a noticeable number of problems with third-party soundbars and cheap multi-channel systems worldwide. And that is striking.

Please read post #77 und #79.
You can explain to the more than 10 owners of such TVs in my circle of friends and acquaintances that it is not a problem with these TVs, but none of them will take it seriously. And we tested it extensively.
E.g. Sony TVs don't pose a problem, just like my cheap 4K UHD Chiq. All DACs worked perfectly on these TVs.

And yes, the proportion of high-quality 2-channel DACs connected to TVs is very small and a niche market, as you can see from paid statistics. Well over 96% of 2-channel DACs are distributed between normal home hi-fi, devices connected via USB and pro audio.

 

[formdissolve]

What difference does the DAC chip make to the optical transmission process? There's a transmitter and a receiver. They should both work to standard, whether what's after the receiver is an overpriced uberDAC product or a smart speaker.

@Galliardist DAC chips from different manufacturers use different PLL techniques, hence why there are so many people with modern 2-channel ESS-based DAC's having issues using the optical port from their TV's. "The default jitter rejection values used by ESS based DACs recognize the extreme noise (such as the noisy signal from LG OLED TV's like the C9) as signal errors, so the DAC automatically disconnects and reconnects in attempt to achieve a more stable lock of the incoming S/PDIF signal."

"This behavior is the result of the ESS’s otherwise excellent jitter recovery logic. The patented jitter eliminator must periodically unlock and re-sync because the digital stream is so poor. AKM and Wolfson S/PDIF receivers are not asynchronous, so they pass along any significant jitter from an optical source, thus, eliminating any chance of a momentary pause for a SPDIF re-locking event."

 

[Galliardist]

@Galliardist DAC chips from different manufacturers use different PLL techniques, hence why there are so many people with modern 2-channel ESS-based DAC's having issues using the optical port from their TV's. "The default jitter rejection values used by ESS based DACs recognize the extreme noise (such as the noisy signal from LG OLED TV's like the C9) as signal errors, so the DAC automatically disconnects and reconnects in attempt to achieve a more stable lock of the incoming S/PDIF signal."

"This behavior is the result of the ESS’s otherwise excellent jitter recovery logic. The patented jitter eliminator must periodically unlock and re-sync because the digital stream is so poor. AKM and Wolfson S/PDIF receivers are not asynchronous, so they pass along any significant jitter from an optical source, thus, eliminating any chance of a momentary pause for a S/PDIF re-locking event."

Thanks for this information. I wasn't aware of this issue.

There is of course another way to read this. Rather than blaming the DAC for not coping well with a poor incoming signal, we could blame the receiver (and maybe the transmitter) for not passing a good signal (one that does not require the disconnects to take place) to the DAC.

And if this is a known issue, should it be resolved by the designer of the DAC in some way anyway? Is it too hard to do, or will it raise the price too much to the consumer?

As an aside, it's always good to cite the source for quotes in posts. Also, sorry for the negative way this post reads - it's not meant that way, I do appreciate the response.

 

[formdissolve]

Thanks for this information. I wasn't aware of this issue.

There is of course another way to read this. Rather than blaming the DAC for not coping well with a poor incoming signal, we could blame the receiver (and maybe the transmitter) for not passing a good signal (one that does not require the disconnects to take place) to the DAC.

And if this is a known issue, should it be resolved by the designer of the DAC in some way anyway? Is it too hard to do, or will it raise the price too much to the consumer?

As an aside, it's always good to cite the source for quotes in posts.

Yeah, I mentioned that earlier. The JDS Labs report is in the first post of this thread and they actually offer an alternate firmware for their ESS-based DACs to relax the jitter correction so their DAC's work better with TV's that have crappy optical ports.. but I don't know of other companies that do that, and frankly, they probably won't for such a small sector.

I agree that it's the source that's the issue, and as others have stated: TV manufacturers don't care and never will. If their soundbar works, then that's all they care about.

 

[Galliardist]

Yeah, I mentioned that earlier. The JDS Labs report is in the first post of this thread and they actually offer an alternate firmware for their ESS-based DACs to relax the jitter correction so their DAC's work better with TV's that have crappy optical ports.. but I don't know of other companies that do that, and frankly, they probably won't for such a small sector.

I agree that it's the source that's the issue, and as others have stated: TV manufacturers don't care and never will. If their soundbar works, then that's all they care about.

I'm not sure that it is such a small sector. Our local electronics store certainly sell enough cheap DACs for TV optical out to be aware of which ones get regularly returned, and steer customers towards the one that doesn't.

 

[ZolaIII]

I'm not sure that it is such a small sector. Our local electronics store certainly sell enough cheap DACs for TV optical out to be aware of which ones get regularly returned, and steer customers towards the one that doesn't.

It's not if you look at it from TV manufacturers perspective (as those two stand for majority sold one's) but they obviously don't give dammn. Everything else is a more patch than permanent fix of actual problem.

 

[DLS79]

The JDS Labs report is in the first post of this thread and they actually offer an alternate firmware for their ESS-based DACs to relax the jitter correction so their DAC's work better with TV's that have crappy optical ports..

As a developer/engineer I'm of the opinion that this is something that they shouldn't have done. They've now set a dangerous precedent, by basically saying we will fix issues caused by other manufacture.

Troubleshooting - JDS Labs Customer Support

Troubleshoot common issues in the audio chain, including connections, sources, and headphones for both amps and DACs.

jdslabs.com

 

[Galliardist]

As a developer/engineer I'm of the opinion that this is something that they shouldn't have done. They've now set a dangerous precedent, by basically saying we will fix issues caused by other manufacture.

Troubleshooting - JDS Labs Customer Support

Troubleshoot common issues in the audio chain, including connections, sources, and headphones for both amps and DACs.

jdslabs.com

As a customer, I want a product that works. I don’t care that the DAC chip has to drop the signal or that the TV manufacturer “doesn’t care” when they provide an optical out that works with other devices.

 

[DLS79]

As a customer, I want a product that works. I don’t care that the DAC chip has to drop the signal or that the TV manufacturer “doesn’t care” when they provide an optical out that works with other devices.

Then tell the massive TV manufactures to fix their crap as that is where the problem is!

 

[Obizzz]

Then tell the massive TV manufactures to fix their crap as that is where the problem is!

In reality that would mean no fix though. This has been an issue on LG TV:s for years.

It was driving me crazy when we went from a projector setup to a TV a couple of months ago and after some searching it turns out to be a known issue.

Luckily I was actually using a JDS DAC so a simple workaround with the firmware was possible.

Yes, Samsung and LG should fix it on their end but I’d rather have a workaround until they do (which they most likely won’t )

 

[DLS79]

Yes, Samsung and LG should fix it on their end but I’d rather have a workaround until they do (which the most likely won’t )

In North America that's 2/3rds of the high end/quality market, Sony being the other 3rd. Panasonic pulled out of the North American market in 2016.

Sony being the only viable high end manufacture is not that great for audio enthusiasts.

 

[Galliardist]

In reality that would mean no fix though. This has been an issue on LG TV:s for years.

It was driving me crazy when we went from a projector setup to a TV a couple of months ago and after some searching it turns out to be a known issue.

Luckily I was actually using a JDS DAC so a simple workaround with the firmware was possible.

Yes, Samsung and LG should fix it on their end but I’d rather have a workaround until they do (which they most likely won’t )

This isn't the whole story though.
In TVland, they build to the second Toslink standard from the mid 1990s. (LG still fail to meet that standard on some of their sets, as shown by the JDS measurements). Future development for these big manufacturers is HDMI based.
In the land of audio, optical connection has tightened beyond that old standard so that "high resolution" audio can be sent down it. So a proprietary standard is replaced by other proprietary methods.
What ESS did was to introduce a tighter PLL loop as the standard operating mode in their DACs. They are selling to audio companies, after all. They also included a way to loosen that lock to allow all devices that comply with the 1990s standard to work with their chips.
It's all actually quite explicable, and the "workaround" is actually just complying with the standard. It may well be allowing substandard devices to work as well, but that is no reason not to implement that as an option. You could also try for a new Toslink standard, but good luck with that. Samsung and LG are only including optical as a legacy standard, and it will go the way of composite video sockets before too long.

Maybe the audio industry should just be implementing ARC/eARC more widely in stereo equipment now as a modern standard that does the job. Then again, as all subjectivists know, anything HDMI means more jitter and has to be avoided at all costs - especially if that jitter is inaudible.

So let's just embrace the fix, stop blaming the TV companies except when they break their own standard, and get on with listening to music and watching TV.

 

[DLS79]

Maybe the audio industry should just be implementing ARC/eARC more widely in stereo equipment now as a modern standard that does the job. Then again, as all subjectivists know, anything HDMI means more jitter and has to be avoided at all costs - especially if that jitter is inaudible.

I personally don't know of any dac that has an arc/earc input.

Maybe someone can convince @amirm to start testing converters. I see arc/earc "converters" and "extractors" all over the place. Maybe someone makes a decent one.


I helped my father set up a new Sony shortly before Christmas and he was annoyed because most of the i/o was over hdmi.

 

[-Matt-]

Maybe someone can convince @amirm to start testing converters. I see arc/earc "converters" and "extractors" all over the place. Maybe someone makes a decent one.

He is way ahead of you!

For example:

https://www.audiosciencereview.com/...amazon-basics-4k-hdmi-extractor-review.39467/

https://www.audiosciencereview.com/...ei-hda-939-hdmi-audio-extractor-review.42948/

https://www.audiosciencereview.com/...-blackbird-review-hdmi-audio-extractor.36478/

I personally don't know of any dac that has an arc/earc input.

Would this count?

https://www.audiosciencereview.com/...rements-of-essence-hdacc-ii-4k-hdmi-dac.7171/

 

[Obizzz]

He is way ahead of you!

For example:

https://www.audiosciencereview.com/...amazon-basics-4k-hdmi-extractor-review.39467/

https://www.audiosciencereview.com/...ei-hda-939-hdmi-audio-extractor-review.42948/

https://www.audiosciencereview.com/...-blackbird-review-hdmi-audio-extractor.36478/




Would this count?

https://www.audiosciencereview.com/...rements-of-essence-hdacc-ii-4k-hdmi-dac.7171/

Those are not eARC compatible though. You have to put the signal through them and then to your TV and that will probably mess up a bunch of stuff such as Dolby Vision etc.