Why do USB cables make such a difference?

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Dec 9, 2018 at 5:32 PM Post #1,516 of 1,606
Sure, but in our defense that's only because that's not true. Mostly that's likely due to the USB audio spec (as opposed to the USB bulk spec) guaranteeing bandwidth but no error correction, thus errored bits in a word (noise) or mis-timed bits (jitter) can get directly converted by the DAC into analogue ... but really we don't know. (no matter what the inbred groupthink would tempt you to believe)

So feel free to bust out your source-side / DAC-side data analysis showing you're right, but realize you'll have to know the XMOS or C-media USB receiver chip firmware code, which is a trade secret, so you'll likely be easily identifiable by them, and nobody here would ask you to break your contract.

Or ... you don't have that data, don't know what that code says, and you're guessing.

My bet is on the latter.
I've been working on computers for decades. Mine is an educated guess as opposed to one formed by marketing material. May I point out you dont have data either?

Actally, you want data? Transfer a file over usb and see how many CRC errors you get with different cables?
Hint: None.

Watch a 1080p, or even 4k, video over USB and see how much jitter and artifacts you get compared to the original file.
Hint: None.

You can transmit 1080p video, which requires a lot more bandwidth, over a simple cable that you can buy for $10.

The maximum bandwidth is determined by the host, not the cable.
USB 2 is 60 MB per second and USB 3 is 640 MB per second. The bottleneck is not the cable but the controller type.

Please tell me how you need a special USB cable to transmit music.
 
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Dec 9, 2018 at 5:48 PM Post #1,517 of 1,606
It does not. You're an amateur on this topic, and the fact that you don't understand that is how we know it's true.

Any competent engineer or scientist who gets paid to make decisions that affect people's jobs, money, or lives would never misrepresent themselves or their knowledge, and understand the difference between bet-your-money facts and we-don't-know-yet guesses.

That's why they're paid to make decisions and you are not.


You keep referring to working in an engineering field where lives are at stake and therefore no guesswork is involved. Can we dispense with that fallacy?

Let’s take an air launched missile as an example - certainly lives are at risk. Air to air or air to ground present the same or similar variables that need to be accounted for and to suggest that every permutation is tested and the outcomes fully known isn’t reality. While many are tested for, most combinations are rationalized based on “guesses” made via our current knowledge of the science involved.

To intimate that all scenarios are fully understood and accounted for would require all possible permutations of the following to be tested - I fully acknowledge that this is not the complete list. Temperature, atmospheric pressure, wind speed, humidity, continuous and variable wind shear, airborne particulate type, airborne particulate volume, and numerous others.

Then, every possible permutation of that list would need to be tested against every situational and operational variables, including pressure waves and temperature gradients resultant from other ordinance in the area of operations, physical and electronic countermeasures, and many more - that should be a long enough list to make the point.

In reality, there are actually far fewer environmental variables in USB data transport than the scenario described above. While neither are fully permutationally tested, both are based on enough known science to be rationally assessed and for reasonable conclusions/outcomes to be determined. At some point, finite data sets require exception based programming to account for unknown conditions/variables. Or more basically stated, guesses to be made based on the best information available. If and when new information is available, change may be required.
 
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Dec 9, 2018 at 5:54 PM Post #1,518 of 1,606
You keep referring to working in an engineering field where lives are at stake and therefore no guesswork is involved. Can we dispense with that fallacy?

Let’s take an air launched missile as an example - certainly lives are at risk. Air to air or air to ground present the same or similar variables that need to be accounted for and to suggest that every permutation is tested and the outcomes fully known isn’t reality. While many are tested for, most combinations are rationalized based on “guesses” made via our current knowledge of the science involved.

To intimate that all scenarios are fully understood and accounted for would require all possible permutations of the following to be tested - I fully acknowledge that this is not the complete list. Temperature, atmospheric pressure, wind speed, humidity, continuous and variable wind shear, airborne particulate type, airborne particulate volume, and numerous others.

Then, every possible permutation of that list would need to be tested against every situational and operational variables, including pressure waves and temperature gradients resultant from other ordinance in the area of operations, physical and electronic countermeasures, and many more - that should be a long enough list to make the point.

In reality, there are actually far fewer environmental variables in USB data transport than the scenario described above. While neither are fully permutationally tested, both are based on enough known science to be rationally assessed and for reasonable conclusions/outcomes to be determined. At some point, finite data sets require exception based programming to account for unknown conditions/variables. Or more basically stated, guesses to be made based on the best information available. If and when new information is available, change may be required.
That's why CRC checks exist, to confirn data integrity.
 
Dec 9, 2018 at 5:59 PM Post #1,519 of 1,606
That's why CRC checks exist, to confirn data integrity.

Agreed, though CRC checks aren’t generally done on audio data during playback via USB. That said, the error rates identified on audio streams in the studies I’ve seen are low enough to be considered negligeible and not audible. Either way, as you suggested earlier, a cable wouldn’t be the source or remediation point for those errors in normal use cases.
 
Dec 9, 2018 at 6:00 PM Post #1,520 of 1,606
I really should learn my own lesson and stop addressing these self important internet duffers.

There's no reason to worry about data transfer in a USB cable unless you're experiencing obvious problems like stuttering and dropped connections. And if that's the case, the source of your problem is almost certainly not the cable. And in the unlikely case that the cable is the problem, just replacing it with a standard Amazon Basic USB cable will fix the problem.
 
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Dec 9, 2018 at 6:03 PM Post #1,521 of 1,606
You keep referring to working in an engineering field where lives are at stake and therefore no guesswork is involved. Can we dispense with that fallacy?

There are many fields that require professional licenses:
* Law
* Civil Engineering
* Medicine
* Electrical Engineering
* Accounting
* Aviation

The reason for this is because the advice those professionals provide risks people's money, jobs, or lives. For example, take a producer of pacemakers: they have to be pretty fecking careful with their electronics since they're betting shareholder money, company jobs and careers, and the recipients lives. Aircraft mechanics doing maintenance on a two-engine aircraft about to fly 3000 miles over an ocean have to be pretty sure why that electrical fault happened, and why it's not going to happen again. They sign their names attesting to it, and you've likely bet your life on their decision.

The point is, there are measure twice, cut once professions, and people who work in those professions learn the difference between what is known and what is guessed.

Anyway, the answer to your question is, no we can't.
 
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Dec 9, 2018 at 6:06 PM Post #1,522 of 1,606
I think the internet should have a minimum standard for posting.

Upgrading USB cables is a lousy way to improve your sound system. It is pure bling with no audible benefit. You might as well stud your headphones with rhinestones and plate your DAC with 14k gold. It's all flash and no substance.
 
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Dec 9, 2018 at 6:13 PM Post #1,523 of 1,606
There are many fields that require professional licenses:
* Law
* Civil Engineering
* Medicine
* Electrical Engineering
* Accounting
* Aviation

The reason for this is because the advice those professionals provide risks people's money, jobs, or lives. For example, take a producer of pacemakers: they have to be pretty fecking careful with their electronics since they're betting shareholder money, company jobs and careers, and the recipients lives. Aircraft mechanics doing maintenance on a two-engine aircraft about to fly 3000 miles over an ocean have to be pretty sure why that electrical fault happened, and why it's not going to happen again. They sign their names attesting to it, and you've likely bet your life on their decision.

The point is, there are measure twice, cut once professions, and people who work in those professions learn the difference between what known and what is guessed.

Anyway, the answer to your question is, no we can't.


Either you didn’t read my post or chose to ignore the content because it’s clear that within even the riskiest of engineering and science fields, guesswork, even if educated, is required. Your strawman resoponse listing fields requiring accredation/certification doesn’t change that. Even your own words, stating aircraft mechanics “have to be pretty sure” indicates there is educated guesswork involved.

That’s not to discredit what they do, just to highlight that your claim that those fields operate solely on established and settled science is indeed a fallacy.
 
Dec 9, 2018 at 6:16 PM Post #1,524 of 1,606
How can one person waste so much time and energy? It's like a black hole sucking everything into nothingness. We seem to attract black holes lately. I don't have time to waste on foolishness.

Perhaps the solution is to just reply with...

No.*


* see above

Either way your read that it has the same effect.
 
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Dec 9, 2018 at 6:23 PM Post #1,526 of 1,606
How can one person waste so much time and energy? It's like a black hole sucking everything into nothingness. We seem to attract black holes lately. I don't have time to waste on foolishness.

Perhaps the solution is to just reply with...

No.*


* see above

Either way your read that it has the same effect.


Technically, black holes don’t suck things into nothingness. Once inside the schwarzschild radius...

I’m assuming you weren’t referring to my responses. But you do have a point about not investing the time. I just don’t like leaving some of the navel gazing unchallenged in case others drop into this thread without context.
 
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Dec 9, 2018 at 6:26 PM Post #1,527 of 1,606
Back on the topic of measurements, this interview with industry legend Dan D’Agostino is super interesting:

TLDR: measurements are good design guides but not definitive for sound quality



I suspect this same understanding (or lack thereof) of measurements is also happening with cables, DACs, and everything else audio


Now this is an interesting case. Years ago we reverse-engineered one of his Krell amps. It did not have zero feedback as claimed, but had around 3dB of feedback around the output stage only. This figure is interesting, as if you look up the chart in John Lindsea-Hood's book on amplification, 3 dB is the point where feedback not only increases distortion, it adds the most distortion. Whether this is true for the Krell's unusual topology I cannot say, but we also listened to it. Used them (as they were monoblocks) as a benchmark in the listening room for a while. However it became clear that wile they sounded good, quite enjoyable, they were coloured, particularly in the bass. They measured fine by the way: flat frequency response, reasonable THD etc.

We were not the only group that found this. Several other companies moved away from Krell as a reference as Krell moved towards a less neutral sound. This was deliberate I think, as their early stuff was great.

I know this is contrary to my mentioning other brands comment from before, but this was a brand that deliberately moved away from neutral transparent reproduction to a coloured sound.
 
Dec 9, 2018 at 7:04 PM Post #1,529 of 1,606
102 pages and no objective data showing usb cables having an audible effect or don't.
Just the usual rubbish about science doesn't know everything and can't prove anything.

FTFY

Also, answering the USB cable question isn't a science question - we just need an analysis of what was sent from the source, what the chip received, and what the chip output across a representative set of DACs in representative environments. Boom, answered.

Since we don't have that, everyone is arguing over their speculations, and many don't even realize they're speculating, despite the fact this is the science thread.
 
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Dec 9, 2018 at 7:34 PM Post #1,530 of 1,606
FTFY

Also, answering the USB cable question isn't a science question - we just need an analysis of what was sent from the source, what the chip received, and what the chip output across a representative set of DACs in representative environments. Boom, answered.

Since we don't have that, everyone is arguing over their speculations, and many don't even realize they're speculating, despite the fact this is the science thread.
Um, you do realise that digital audio data is just data, right?
There are decades of evidence supporting the point that a cheap USB cable works as well as an expensive cable. Otherwise we would be getting CRC errors all over the place when transferring data over USB. Portable hard drives would be unusable without an expensive USB cable.
 
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