Jittter

[Nasutobaknarf]

Went from a 5G cellphone hotspot (!) to using a 5G router. My CXN100 is connected to the router with a Supra Cat8 Ethernet cable, and my PC with the cable that came with the router.
Typical connection speed is 200 to 400 MBit/s and the sound has improved again, something I thought impossible but a nice surprise.
Checked the connection's quality on Packet Loss Test and no packets are lost. The test indicates there is jitter of 5 to 7 ms which is a bit concerning when good DDCs have femtosecond clocks. I don't know if the cheap Ethernet cable I use with the PC is involved, but I have a better cable coming soon. If the cable doesn't matter in this regard, it means the streamer is fed with a signal with significant jitter. Can and will it correct this, does it have a detrimental effect on the sound quality, and if not, could a DDC even handle such amounts of jitter?
Thanks in advance!

//L

 

[sonitus mirus]

You seem to be confusing network transport jitter with a DAC's clock jitter. The jitter associated with a network connection is buffered and has no effect on sound quality unless it is atrociously bad, which potentially could introduce dropouts, stuttering, or pauses in playback. Generally, your ethernet cable has no objective influence on clock jitter occurring inside your DAC.

 

[Nasutobaknarf]

You seem to be confusing network transport jitter with a DAC's clock jitter. The jitter associated with a network connection is buffered and has no effect on sound quality unless it is atrociously bad, which potentially could introduce dropouts, stuttering, or pauses in playback. Generally, your ethernet cable has no objective influence on clock jitter occurring inside your DAC.

Thank you very much, I feel reassured hearing this from a knowledgeable person!

//L

 

[sonitus mirus]

Thank you very much, I feel reassured hearing this from a knowledgeable person!

//L

I am still learning as I go, and I really appreciate how helpful and smart everyone here is.

 

[kemmler3D]

does it have a detrimental effect on the sound quality, and if not, could a DDC even handle such amounts of jitter?

Just adding a +1 to @sonitus mirus 's answer that no, it does not affect sound quality.

Internet traffic is sent via packets and due to things like this, the protocols are delay- and error-tolerant. What happens is your CXN100 will most likely be taking in internet traffic and assembling the data as data. At this point it's not an audio stream yet. It's probably downloading a bunch of the song, likely the whole thing, probably even multiple songs from the queue at once. a 300-400 Mbps connection is nearly 100x more data than a 24/96 audio stream uses.

Once the song is at least partly downloaded from the internet, the streamer will read the audio file and send the data to the DAC, which itself very likely has its own buffer to deal with jitter even further.

A few ms of jitter in an audio stream would indeed sound bad, but the internet connection and the data going through the DAC are totally decoupled in time, so it's not a problem and the actual audio jitter ends up being measured in nanoseconds, or thereabouts.

Also:

Typical connection speed is 200 to 400 MBit/s and the sound has improved again, something I thought impossible but a nice surprise.

For the same reasons, this probably IS impossible. It's super common to hear non-specific improvements to audio when we change something in the system, no matter what we changed - maybe chalk it up to paying closer attention when we hit play when something in the system is new or different.

 

[Nasutobaknarf]

Just adding a +1 to @sonitus mirus 's answer that no, it does not affect sound quality.

Internet traffic is sent via packets and due to things like this, the protocols are delay- and error-tolerant. What happens is your CXN100 will most likely be taking in internet traffic and assembling the data as data. At this point it's not an audio stream yet. It's probably downloading a bunch of the song, likely the whole thing, probably even multiple songs from the queue at once. a 300-400 Mbps connection is nearly 100x more data than a 24/96 audio stream uses.

Once the song is at least partly downloaded from the internet, the streamer will read the audio file and send the data to the DAC, which itself very likely has its own buffer to deal with jitter even further.

A few ms of jitter in an audio stream would indeed sound bad, but the internet connection and the data going through the DAC are totally decoupled in time, so it's not a problem and the actual audio jitter ends up being measured in nanoseconds, or thereabouts.

Also:



For the same reasons, this probably IS impossible. It's super common to hear non-specific improvements to audio when we change something in the system, no matter what we changed - maybe chalk it up to paying closer attention when we hit play when something in the system is new or different.

Thank you for this explanation.
Re the sound quality, yes I know I'm prone to placebo effects but I avoid having preconceptions what to expect when making various adjustments, in order to not become a victim of confirmation bias. The phone I used for a hotspot was a 5G phone but typical connection speeds were 40 to 65 MBit/s and its wifi function probably questionable. I've been on a steady course with small but noticeable improvements here and there. With a Topping E70 Velvet downstreams after the CXN100, I though I was in audiophile heaven and that the new router barely would be noticeable.
What I notice is a better stereo separation and an improved midrange, furthermore a more 'natural' and 'authoritative' sound. Ah yes, it's airier, too
I rather like it, but wouldn't have wept if there was no change. It is slightly different rather than massively better. What this comes from is beyond me, but using the Ethernet cable instead of wifi might play a role. I'm in an environment with many home networks and cellular masts densely packed, so there is probably a lot of electromagnetic interference here.

//L

 

[Jim Taylor]

I avoid having preconceptions what to expect when making various adjustments, in order to not become a victim of confirmation bias

Avoiding preconceptions does not prevent you from becoming a victim of confirmation bias.

There is no deliberate way to avoid bias. Bias is the fuel that the brain uses to make fast decisions for our survival. Bias takes control of our brain far faster than conscious and deliberate thought can be formulated. It's why the human race has survived.
The bad part is that bias is not always right ... and to tell the truth, it doesn't need to be. It just has to guide us to safety. Is this place warmer than where I was yesterday? Does this water taste better than that other river this morning?
Particularly, our hearing is subject to biases. Is that sound louder than it was a minute ago? Is that squawk I heard a sign of pain or aggression?

All of these things are going 'round and 'round in our mind all the time. We can't eliminate them. But we CAN control their effects. Through discipline, through understanding of the different biases and how they work, and through rigorous control of the exposure we have to a stimulus, we can achieve adequate control over bias. It's not easy, and it takes attention to detail, but it can be done.

That's the purpose of the Double Blind Test. It doesn't eliminate bias , it simply creates a situation wherein discipline and rigor reduces the effects of bias to a degree that the conclusions are reliable.
Any comparisons that are not subjected to the proper rigor and discipline are not reliable, NO MATTER HOW STRONG OUR IMPRESSION SEEMS TO BE.

That's why we have measurements made with instruments. Instruments have no emotion or bias.

 

[kemmler3D]

It is slightly different rather than massively better. What this comes from is beyond me, but using the Ethernet cable instead of wifi might play a role.

It's physically impossible for that to play a role, to put it bluntly. Bits are bits and if they are hitting the buffer in front of the DAC via Wi-Fi or carrier pigeon, it has no idea.

If the audio stream could change based on your Internet connection, so could your banking details, the text of this post. Etc. As we know, this doesn't happen because the Internet is very cleverly built to avoid that. You get the same data via Wi-Fi, cable, fiber, 5G, or otherwise.

And if the audio data is exactly the same, the same sounds will be coming out of your DAC. How could it be otherwise?

Placebo effects are subtle and *convincing* ... But placebo they are, nonetheless.

 

[Chrispy]

FWIW you seem to have odd expectations about differences and am guessing on unreliable sources of such information. What are your sources / gathering of information about audio gear?

 

[Nasutobaknarf]

Reply to all:
First things first. I'm grateful for now knowing the network jitter has nothing to do with clock jitter. It resonates well with my finding that the sound quality now is as good as anyone could expect from a system like mine.

My previous internet connection, with a cellphone used as a wifi hotspot, delivered surprisingly good results sonically. I have very good 5G coverage with 300-500 Mit/s but its wifi speed was usually about 40 MBit/s, certainly enough for hires music streaming but not for video. Watching Youtube videos with 4K resolution could work well, but never reliably and persistently. The automatic video quality selection chosen by the Youtube server often chose 480p. I didn't run the Packet Loss Test frequently, but when I did, lost packets weren't unusual. Image degradation is a lot easier to spot than intermittently subpar sound degradation, plus video demands better speed, bandwidth and reliability. The cellphone was initially meant to try out the 5G connection and then be replaced with a proper router, not as a permanent solution. But it performed so well that I felt no need to hurry the swap.
Nobody could make me believe there's no difference at all between a ****** phone not meant to be used as a router, and a proper router that forwards the full bandwidth and speed. Upon that, I chose to go with a shielded Ethernet cable instead of wifi, but I don't believe I'd be able to hear a SQ difference had I used wifi with my new router. That refers to the cable to the streamer. My reason for buying a second cable, that one for my PC, is only that I need it to be longer.

Re placebo and confirmation bias et cetera. I want to stress that I had not been reading anything about what to expect when making this change. Well aware that there are people who lose their minds when constantly trying to improve their system, for example buying cables for several hundred thousands bucks. Luckily, I don't have the funds to do this. As far as I can see, I'm now at end game. Theoretically I could swap out the E70 Velvet DAC, but I'm so fond of its sound that I see no reason for that. Any other change would mean a total teardown and exchange, and that doesn't interest me. I'm in it for the music. Which leads me into the last paragraph...

Anything we experience with our senses is entire subjectively, an interpretation. There is nothing such as truth involved. What measurements can do is to compare the source with the output, and that's that. But there are a couple of culprits. Are we absolutely certain that we know every possibly measurable parameter, and if not, might it contain anything of value for our experience? I know I'm out on the limb here, but rest assured I don't believe there exist such parameters but it shouldn't hurt to question it anyway.
The other end - the source - is more problematic. It is inherently only a rendition meant to be enjoyable, and just like the 8K movie on a high end TV, it has nothing to do with truth or reality, only enjoyment, and in the best case scenario it has a rudimentary element of fidelity or faithfulness to reality.

As a side note, there are scientists and philosophers that argue that reality doesn't even exist the way we perceive it, and that our consciousness may even construct 'reality', meaning the physical world, spatial and temporal dimension and thir content including our brains. Donald Hoffman goes this far, and his videos are very intriguing.

Unless we're into HiFi for anything else than entertainment and enjoyment, judging by our own ears is sufficient although the confirmation bias has the power to lead dumb people into very costly adventures. It's crucial to know when to stop.
Measurements can only relate to aberrations in the output compared to the source material. The source isn't the truth, it's a small slice of the reality that existed when the recording was done, if reality even exists. The gear reproduces this slice, and by ensuring no component subtracts any valuable part of the information we can enjoy a fairly correct reproduction. And enjoyment needn't necessarily be related to the degree of fidelity.

//L

 

[kemmler3D]

judging by our own ears is sufficient although the confirmation bias has the power to lead dumb people into very costly adventures. It's crucial to know when to stop.

I want to stress that I had not been reading anything about what to expect when making this change. Well aware that there are people who lose their minds when constantly trying to improve their system

I just want to raise a flag on your approach to hearing things due to placebo effect. I may be detecting a little defensiveness in your reply, and it's not something that affects "dumb" people or those who "lose their minds", it hits everyone. From time to time even Amir mentions he hears a difference from a product being tested (say a USB isolator) even when the measurements show absolutely no difference at all.

I've worked in the audio industry and auditioned speakers and headphones as part of my job. The reputation of the brand hinged on my listening, to a significant extent. I've found myself hit by placebo effect *and I knew it* once or twice because I heard (smaller than expected) changes from tweaking an EQ filter that was actually disabled.

I also ran a survey on our customers once and found that a wide majority of them were experiencing placebo effects. I shipped a firmware update that didn't touch sound quality, then asked them to rate the change in sound quality. Surprise, most people said it got better.

My point is that placebo effect is much more pervasive and hard to avoid than you might think, and if you experience it, it only means you are human, not that you have failed to listen critically enough, or that something is wrong with your brain. Professionals know this because they get exposed to it often enough that once in a while they're lucky enough to catch it in the act.

So, I don't know what your sources are, and if you have a bad connection, Youtube or whatever can definitely lower the streaming quality. And that could be audible, sure.

But if you're getting the same files streamed to you, the connection simply can't affect the sound. In that case it would just have to be placebo, or at least something other than the connection speed.

But I definitely don't want to leave you with the impression that hearing changes that don't exist is some kind of failure or mistake, it's simply how our ears work.

 

[Nasutobaknarf]

But if you're getting the same files streamed to you, the connection simply can't affect the sound. In that case it would just have to be placebo, or at least something other than the connection speed.

That is an utmost puzzlingly reply because it implies that the prevalence of lost packets cannot affect the sound quality at all, which in turn means that a turned-off connection could deliver a perfectly decodeable file. A kinder interpretation would be that you mean that it's not the same file if it's compromised.

The buffer is obviously not infinite, and it can't wait forever for data packets that never entered the stream. As long as a sufficiently fast connection is perfectly stable, the buffer will contain all the packets and provide a comfortable 'headroom' for the DAC.

It's not a bold guess that my previous 'router' had more errors with lost packets when speed approached the critical lower limit. I have no idea why its wifi distributed a mere tenth of what the 5G network was capable of, but I am sure its variance of performance must have affected the streaming sound (and yes, it's hires streaming I'm into), although not as apparent as it sometimes did with the video.
It would probably have been better to connect the phone directly to the DAC over USB, quality-wise.

You misinterpreted my use of 'dumb' - it didn't refer to those affected by the placebo effect, but to those who go way too far acting upon it. I'd certainly say that anyone paying tens or hundreds thousands of dollars on cables is out of their mind.

//L

 

[kemmler3D]

That is an utmost puzzlingly reply because it implies that the prevalence of lost packets cannot affect the sound quality at all, which in turn means that a turned-off connection could deliver a perfectly decodeable file.

Yes, but lost packets are actually extremely rare. I've read reports of people running data center switches for a year at a time (at many, many times the throughput of a home connection) without a single lost packet.

When packets fail CRC (cyclic redundancy check) they get re-sent, multiple times if need be. And, remember that even a 30mbps connection is several times faster than 24/96 uncompressed audio needs, let alone compressed audio, so if a packet gets lost, there's PLENTY of time to re-send it before the buffer runs out.

The data is also sent asynchronously from playback. Spotify, for example, will load 3 or 4 tracks at a time in advance. So a drop in the connection doesn't actually affect the data being sent to the DAC.

And, all that said, if you do lose enough packets to run out of buffer, the music will simply stop or have obvious gaps. You wouldn't hear a subjective change in quality, it would simply be off / on based on whether the data is there or not.

If you heard a genuine subjective change in quality due to speed or quality of connection, it's probably because the streaming service bumped you down to a lower quality, not something inherent to the connection itself.

I'd certainly say that anyone paying tens or hundreds thousands of dollars on cables is out of their mind.

Certainly agree. Crazy or crazy rich, maybe both.

 

[Nasutobaknarf]

Yes, but lost packets are actually extremely rare. I've read reports of people running data center switches for a year at a time (at many, many times the throughput of a home connection) without a single lost packet.

When packets fail CRC (cyclic redundancy check) they get re-sent, multiple times if need be. And, remember that even a 30mbps connection is several times faster than 24/96 uncompressed audio needs, let alone compressed audio, so if a packet gets lost, there's PLENTY of time to re-send it before the buffer runs out.

The data is also sent asynchronously from playback. Spotify, for example, will load 3 or 4 tracks at a time in advance. So a drop in the connection doesn't actually affect the data being sent to the DAC.

And, all that said, if you do lose enough packets to run out of buffer, the music will simply stop or have obvious gaps. You wouldn't hear a subjective change in quality, it would simply be off / on based on whether the data is there or not.

If you heard a genuine subjective change in quality due to speed or quality of connection, it's probably because the streaming service bumped you down to a lower quality, not something inherent to the connection itself.


Certainly agree. Crazy or crazy rich, maybe both.

Thank you for your patience. I'll add that the StreamMagic app for the streamer now works more reliably and connects faster. Commands from the phone, like changing the source, should require less speed and consume less data than the stream, but were prone to failure.
I can't understand this as anything else than a very unstable WiFi function.

Anyhow, 'all is well that ends well', and my current satisfaction with my system means I'm at end game now. No other type of product has to be added, and none should be swapped for a better version. I'm so confident about this that I actually bought a spare DAC of the same model should the first break (both bought used, as I always prefer). Only after both are broken could I get something better.
The itch will probably come back though, but I'll resist.
Thank you again!

//L

 

[kemmler3D]

my current satisfaction with my system means I'm at end game now. No other type of product has to be added, and none should be swapped for a better version. I'm so confident about this that I actually bought a spare DAC of the same model should the first break (both bought used, as I always prefer). Only after both are broken could I get something better.
The itch will probably come back though, but I'll resist.
Thank you again!

All's well that ends well indeed! Being happy with our setups is the goal, after all. I guess my interest is in helping you (or others reading) find one less thing to worry about or seek improvement for, since it sounds like your system is otherwise checking all the boxes.

(both bought used, as I always prefer). Only after both are broken could I get something better.

+1 on buying used - less burden on the wallet and planet alike.

 

[voodooless]

That is an utmost puzzlingly reply because it implies that the prevalence of lost packets cannot affect the sound quality at all, which in turn means that a turned-off connection could deliver a perfectly decodeable file. A kinder interpretation would be that you mean that it's not the same file if it's compromised.

You clearly don’t understand how common network protocols work.

Do you see missing letters here on the forum? Is the layout broken because it misses bits of data?

So why then would you assume this would happen with an audio stream?

These protocols are build to be reliable. They will make sure that all data is delivered, or else cut the steam.

As for unplugging your cable: it is very likely that that does nothing and will finish at least the song. The data is buffered and cached at various stages in software. Likely the song is already available fully in many cases, or will be after the first few seconds of the song, even on 5G.