Don't get why "Audiophile" USB Cable would improve sound quality - Page 46  

The terms (non)believer or subjectivist/objectivist are just convenient short descriptives of the different sides of the debate. The problem with much of the believer side's evidence is that it is untested speculation.

ahoy mateys.

well now, usb.org have actually replied.

may the light of non-placebo and 'omg I feel the powarh and warmth of mai cable' be witu and stuffs

http://www.head-fi.org/forum/thread/565791/on-usb-cables-and-controller-transfer-modes-a-series-of-questions-to-replies-from-usb-org
Edited by svyr - 8/5/11 at 9:03am

It baffles me how people can still maintain that the cable "designers" know better than the people who designed the entire specification.

it also baffles me that no one bothered to ask the specs people before, since they're kinda partially there for this kind of thing and it seems will gladly exorcise the infernal audiopedophile unicorn with us. although I'm pleased to report for me and you they just confirm what we thought ... on the other hand, I'm sure the devotees of magical 'thickness of your usb cable is proportional to soundstage' clan will no doubt claim their setup is polluted by evil EMI and their cables save them.
alas, not much we can do for them but *patpatpat*

anyway, hopefully that makes a meaningful contribution to 'buy properly designed gear and to spec cables' rather than wasting money on snakeoil bs.
Edited by svyr - 8/5/11 at 9:11am

svyr: Thank you! Very good info from the true experts on this subject.

 

> It baffles me how people can still maintain that the cable "designers" know better than the people who designed the entire specification.

 

What saddens me even more is how so many people on these forums will now be inevitably be trying to argue with the words from the people who designed the thing (USB). Remember the earlier comments by a poster (who I won't name) who said, specifically, that he distrusts and disrespects engineers and scientists. Reminds me of the phrase 'biting the hand that feeds you'.

Edited by ac500 - 8/5/11 at 9:12am

So USB.org don't get why "audiophile" USB cable would improve sound quality.

 

It is worth pointing out that no audiophile cable company has any official endorsements, no peer reviews of their science, nothing. I would be convinced if USB.org put their name to an audiophile cable confirming that it improves sound quality.

Your original question is still the best.  Why do some people hear differences?

Psychoacoustics via expectation bias.

The question "why?" has been answered. The sad part is that there's a general unwillingness to admit to oneself that one is under the influence of placebo. It's human nature and we're all susceptible to it to varying degrees.

 

Edited by JuicyBruce - 9/19/11 at 9:14pm

 

I, for one, expect any company actively engaging in consumer fraud by marketing grossly overpriced USB cables to at least have the common decency to bribe a non-profit's official or at least a well-respected academic to support or lend credence to their product. Drop 100k on buying an AES recommendation and I'm sure the increase in sales will more than make up for the investment. But then we have these hoighty-toighty professional organizations with their "ethics codes" and adherence to validated science, for shame!

 

AES proph measurement and DBT =) they'd want a repeatable procedure and someone will likely publish a paper retesting... so um yea, but no.

Has anyone noticed that the people who report differences always report these differences in areas which are completely subjective and non measurable?

 

Examples of these "perceived differences" are : Improved soundstage, increased air between instruments etc.

 

I notice that people who report improvements between USB cables it is always in these areas which are so subjective and so easy to just imagine a difference.

This is often true - qualities such as soundstage and instrument separation are quite difficult to pin down.  This could possibly be because many cables are all but indistinguishable - in my experience differences between say one copper USB cable and another are almost impossibly to cleary tell.  Much like with an SPDIF cable once you have a constant impedance (90 ohms for USB) changes are difficult to discern and to be honest from a technical standpoint this is what you would expect.  After having constant impedance, some cables have silver plated conductors which apparently can improve the signal waveform integrity by creating a more constant impedancy/frequency curve.  This probably depends a lot on the wire gauge, plate thickness etc and to be honest could be complete nonsense unless the cable designer shows some numbers to back this claim up.  The last thing that in theory can affect USB cable performance is cable length - where a shorter cable of the same construction should give better jitter performance as predicted by the USB standard paper.  The last factor is the succeptibility of the USB audio interface itself to jitter, along with other factors which may introduce jitter or noise into either the D/D converter or directly into the DAC.

 

You are quite right that soundstage and instrument separation are qualities which are rather easy to get confused about, and also in my experience many digital cables I have tested are very difficult to tell apart - I'm pretty sure I would fail a blind test with say 75 ohm SPDIF cables or USB cables of the same length and conductor type.  Personally I have heard more differences between USB ports and galvanic isolators than between different copper USB cables.  BUT I am personally quite certain I can discern between a copper USB cable and the silver plated copper cable I am using, and equally there is evidence that in theory different USB cables have different levels of jitter.  BUT the effects of jitter on D/D and D/A converters is fairly controversial, in no small part because there are innumerable variables in terms of hardware, but mostly because it is relatively simple to demonstrate that relatively large magnitudes of jitter (beyond that of any decent equipment) are not audible.

 

As you can see I personally am in quite a precarious position - I am forced to admit that on an priorised-knowledge level one cannot clearly predict that jitter will be audible.  However, based on experience I can say that elements such as USB cables have lead me to experience and articulate clear differences between USB and computer side hardware and software changes which I cannot readily explain and yet which I would not put down to cognitive bias.  As I already said I like to think I am willing to concede when I cannot clearly hear differences or when I hear negative differences.  When this happens I sell equipment very quickly as I would rather spend the money elsewhere.  Life would be much easier if I were an electrical or audio engineer researcher and had access to lab equipment to measure either electrical waveforms or jitter or even distortion levels at the output of the DAC.  Unfortunately most Audiophile tweaks are very short on technical insight and reliant upon anecdotal evidence to measure performance - and while I do not personally consider myself an objectivist - the points mentioned in this post, along with the preceding 45 pages of discussion should act as a warning not to spend too much money on digital cables.

 

EDIT: This is probably not that important but I feel I should mention that personally I prefer to focus on other factors such as bass bloom/tightness, midrange smoothness or grain, and imaging and focus (ie how clear the outline of an instrument can be discerned) along with upper midrange and treble fatigue.  These qualities are again not foolproof, but I personally find these easier to discern that soundstange and "air around instruments".  Best thing to do I would say is once you have selected a DAC -see if you can borrow a fairly short silver plated copper USB cables to compare against the generic USB cable - If you cant hear a clear difference then obviously it is not worth buying such a cable. 

Edited by drez - 5/9/12 at 10:10am

To be honest I cannot even be bothered to mess around trying USB cables until I see some hard evidence other than subjective opinions which conclusively proves that a "audiophile USB" is going to make any difference at all.

 

I am 99% sure that a reasonable quality USB cable will be completely fine to send the data to my async USB DAC.... The nature of this DAC should pretty much eliminate jitter and the cable of reasonable quality which conforms to USB standards should be 100% ok to transfer the data to the DAC.

 

Companies like wireworld and all this IMO are scammers who are trying to make money from snake oil and expectation bias.