Archimago measures Ethernet cables

[Telecine]

9 hours ago, rmpfyf said:

 

As mentioned earlier, I run a fairly decent test protocol here for kernel development which covers network configuration. I am incentivised to do it correctly as rolling changes into the kernel that don't make a difference (or worse) essentially waste my time. It's the near opposite of audiophile purchases - I am spending $0 and expending time on as much. 

 

Happy?

 

Now accept the challenge above, pls.

 

I'm not sure how your experience can readily translate to the consumer-level world. In enterprise and carrier grade networks, they are using QOS, COS, MPLS, VRFs etc to manage these issues, including at the Linux kernel level. All of these technologies are beyond the Ken of the average user.

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[sir sanders zingmore]

8 minutes ago, rmpfyf said:

 

Who said I'm an average user?

I’d be more concerned that he called you Ken  

[Telecine]

14 minutes ago, rmpfyf said:

 

Who said I'm an average user?

 

I wasn't referring to you, the average users of Hi Fi equipment who are members of the site.

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[andyr]

47 minutes ago, sir sanders zingmore said:

I’d be more concerned that he called you Ken  

 

Is that the male equivalent of 'Karen', Trev?  

 

Andy

 

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[kukynas]

not sure what this challenge is about, should we play that 12khz j-test tone with distortion at -140db and confirm if we can hear something or what? 

if you really wanna challenge someone go to google, type "jitter ABX test" and search for available files, download and test for yourself via foobar or any other ABX tool, if you are happy post the results here...

I would expect differences will be also depended on gear used

if you aren't happy with available files just do your own with your jitter injected files, don't know how to so you might need bit of a search...

 

 

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[sir sanders zingmore]

it's a trick question innit?

 

Nothing is audible on that chart because it's not an analog output

[Guest Eggcup the Dafter]

2 hours ago, rmpfyf said:

 

 

21+ hours later not a single person has given it an honest go

Ah, I'm dishonest. Thanks.

 

So I feel free to point out this...

The "required answer" has already been posted by the questioner on page 4. You can all just crib it and everyone's happy.

[BugPowderDust]

1 hour ago, kukynas said:

not sure what this challenge is about, should we play that 12khz j-test tone with distortion at -140db and confirm if we can hear something or what? 

if you really wanna challenge someone go to google, type "jitter ABX test" and search for available files, download and test for yourself via foobar or any other ABX tool, if you are happy post the results here...

I would expect differences will be also depended on gear used

if you aren't happy with available files just do your own with your jitter injected files, don't know how to so you might need bit of a search...

 

 

This will do the trick: https://distortaudio.org

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[BugPowderDust]

Hey Ric / Ken, when  you're ready for a chat about another testing paper, let me know your thoughts on this: https://www.researchgate.net/publication/242508896_Detection_threshold_for_distortions_due_to_jitter_on_digital_audio 

 

I haven't seen this referenced anywhere before in this thread, but it seems to indicate that trained listeners can find it hard to detect jitter at <250 nsec. This is a real world ABX with trained & untrained listeners, with trained listeners outperforming untrained (576 nsec vs 250 nsec thresholds).

 

4. CONCLUSION
In order to determine the maximum acceptable size of jitter on music signals, detection thresholds for artificial random jitter were measured in a 2 alternative forced choice procedure. Audio professionals and semi-professionals participated in the experiments. They were allowed to use their own listening environments and their favorite sound materials. The results indicate that the threshold for random jitter on program materials is several hundreds ns for well-trained listeners under their preferable listening  conditions. The threshold values seem to be sufficiently larger than the jitter actually observed in various consumer products

Edited March 23, 2021 by BugPowderDust
Insert Conclusion

[aussievintage]

12 minutes ago, BugPowderDust said:

Hey Ric / Ken, when  you're ready for a chat about another testing paper, let me know your thoughts on this: https://www.researchgate.net/publication/242508896_Detection_threshold_for_distortions_due_to_jitter_on_digital_audio 

 

I haven't seen this referenced anywhere before in this thread, but it seems to indicate that trained listeners can find it hard to detect jitter at <250 nsec. This is a real world ABX with trained & untrained listeners, with trained listeners outperforming untrained (576 nsec vs 250 nsec thresholds).

 

 

 

From the study  "The threshold values seem to be sufficiently larger than the jitter actually observed in various consumer products."         None of them could reliably hear 250ns jitter.   Begs the question, are we worrying unnecessarily.  (I expect I know how the answers to that will pan out  )

[sir sanders zingmore]

1 minute ago, aussievintage said:

I expect I know how the answers to that will pan out

Well obviously their Ethernet cables were not of sufficient quality ....

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[bob_m_54]

On 22/03/2021 at 4:14 PM, rmpfyf said:

 

Not really, it's not so hard. Simply mark up what defines 'audible' or 'not audible'. 

If you want to list contextual parameters, have at it. Plenty of room for it. Have a go.

 

 

It's not my plot either. This is directly from AM's article. I haven't 'decried' any tests, though in the spirit of criticism being cheap that's a particularly amusing use of the word. I've simply suggested the methods involved leave the results inconclusive. Others have suggested the tests are awesome and true so showing the wee little likes of me and a few others what's what shouldn't be so hard, certainly a lot less effort than musing over which adjective/adverb combinations to slight the question with. I've been led to understand that the irrefutability of these results are so solid that it should be less effort than reading up on a lame beatup attempt and looking for the 'like' button too (hey there, @Satanica, back doing the usual thing I see). 

 

So that's two from two that won't take it on and a half-baked floater.

 

(I'm enjoying the excuses, BTW.) 

Firstly, what may be audible to some is completely inaudible to others. It depends on the hearing capabilities of the subject doing the listening. This can also vary for a person for a number of reasons too, like recent noise level exposure, fatigue and health of the listener.

 

Then, the environmental variables such as ambient audio noise levels, room acoustics, delivery of the sound (speakers or enclosed headphones).

 

Then the scale in the graph. What does it actually represent? is it dBV of the applied signal? This gives no idea of the SPL the subject would receive at his eardrum, unless there is a reference as to what this signal was applied to, in the way of amplification. With enough amplification, you will hear the noise level no matter how low.

 

Edit: I also agree with whoever said it, you do come across quite rude sometimes too.

Edited March 23, 2021 by bob_m_54

[aussievintage]

26 minutes ago, rmpfyf said:

The same paper also states that it's 'not clear, however, if detection thresholds obtained in the present study would really represent the limit of auditory resolution'.

 

But what I quoted was in the conclusion

[BugPowderDust]

34 minutes ago, rmpfyf said:

Try my challenge again - go and draw in 250ns jitter. Show what that looks like.

 

This is not to pick on you aggressively for asking. An even halfway correct attempt at answering this will reveal that the answer is a lot more complex than the data above suggests

I’m not fussed and have a very thick skin.
 

I’ve seen tests with sinusoidal jitter added to a signal, showing a pretty ugly j test for something at even circa 15nsec of injected jitter which becomes very far worse than your j-test exam example at 175nsec. 

 

Using Distort you can easily dial in a mix of jitter at your preferred ratios and then run it through a J test to eyeball it.

 

I’d be curious to actually get some audio, bang in a range of jitter (scenarios for periodic, random and in between) export the audio and actually eyeball the j tests as well as do some subjective listening to see how far off the mark they are here (or not). 
 

I expect my DAC is better than most at resisting the urge to do the jitterbug (wham) when sent signal. Maybe it’s why I don’t see any of this as any appreciable problem to be solved? 

 

 

Edited March 23, 2021 by BugPowderDust

[aussievintage]

1 hour ago, sir sanders zingmore said:

Well obviously their Ethernet cables were not of sufficient quality ....

 

Doesn't matter anyway, the whole study has been rejected just as I knew it would be. 

[Guest rmpfyf]

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Edited March 23, 2021 by rmpfyf

[aussievintage]

3 minutes ago, rmpfyf said:

 

. There is nothing wrong with this paper.

 

You found plenty wrong just a few posts up