USB Cables and audio transmission

This video on USB cables is really well done imo. Very interesting.

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Shame it’s a half hour long video. The written word is so much easier to assimilate at one’s own (usually much faster) pace. In summary, what does it say?

He used different usb cables in a chain including a chord tt dac and a focusrite 212 usb audio interface, and recorded each one used during playback of the same lossless wav file. He then used audacity to invert the recorded results from the focusrite and could play back normal vs inverted. Pitching one cable against another didn’t produce silence. Hence, assuming consistency which he tried his best to eliminate variation, the usb cables he used each delivered a different signal to the dac. Indeed he recorded using the supra twice, one day after the other, and there were differences.

He draws no conclusion about why there are differences, he merely wanted to explore if he could produce differences and record evidence that there were differences.

He assumed the differences were due to the usb cables themselves, and not to any other part of the chain which remained unchanged.

I suppose you could argue that the recordings were not all performed simultaneously, so variation could have been caused by anything else environmental; fluctuations in electrical supply for example. Recording the supra cable twice on consecutive days; was it the usb cable transmission that was the sole variance? And everything else was 100% identical though 24 hours apart.

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He wanted to prove that USB do make a difference from one another in audio. Not saying which is better, but having one he preferred overall.

Well summarized!

Which day did he prefer the supra cable? :wink:

:joy:

Construction of the cable, though not affecting the data within the parameters of the certified category of USB cable, would affect noise rejection and coupling on the ground plane. Same as on LAN cables. Introduced piggyback noise can transfer then to analogue circuits so yes, this can potentially affect the outcome. How audible is hard to ascertain but even with analogue interconnects, a large part of the difference heard isn’t a change in the purity of the analogue signal so much as changes in the amount of noise rejection and on what bands.

That aside, having played with newer USB audio transports like Bulk-Pet, I feel there is far more to be gained by wider adoption of that instead of the standard ASIO transport for USB, than there is in cable design. The massive reduction in processing workload allowed by Bulk-Pet was quite a “ooh that feels very different” moment when I compared the two on the same USB DAC that support both. Certainly larger than the difference between a cheap and expensive USB cable.

Interesting topic! it’s not related to USB cables (a bit off topic maybe), however I found this video about speaker cables and their different frequency responses:

By the way in this channel there’s a series of videos where they also analyze network switches, parallel filters, power conditioners and power supplies.

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Really interesting! Cables are resistance. Different construction methods and materials gives different frequencies responses. More bass, more highs, more définition, more warmth….Which one is better is only in the ears of the beholder.

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At least there’s a proof about cables making a difference, scientifically speaking. However in the end what matters is what we hear and we should all decide accordingly. They should also test completely new cables and see how they change their response after 200-300 hours, that should be another interesting comparison.

This is also very interesting… Just in case…

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Quite so.

Does this help? If the tests showed that all the cables measured identically would people then stop hearing any differences between them?

Well it doesn’t help of course, but I find it interesting that there might be specific reasons for a particular sound signature. Some people (I hope few of them) might not buy different cables just because there are no scientific proofs. I’ve never bought a cable relying on videos or technical data. Like many people here in the forum, I test them, compare them and then decide what to go for according to my preferences. And surely cables can have a big impact in the sound chain, at least this has been my personal experience.

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I agrree that cables have a big impact on sound - no question. Like you I buy things according to their sound - not how they measure.

There will always be those who, for reasons that have always escaped me, prefer to rely on technical data than their ears, or who require ‘proof’ of what their ears tell them. It’s harmless enough, but rather odd in my opinion.

We use our systems to enjoy music. We use our ears to listen to music, not measuring instruments - or at least I do.

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Maybe those people didn’t have the chance to experience what a good cable can do or they are simply convinced that they can rely only on technical data. Who knows!

I remember that some till a certain moment, most cables I’ve heard sounded pretty similar. Then I had the chance to try Nordost cables and that has been quite eye opening. Cables play an essential part in conveying the music feel.

The question of “why measurements?” Is an interesting one. For some of us there is the aspect of wanting to know and understand things - which for me at least has always been a driver in my life, though not everyone is that way inclined.

If two cables tested under the same conditions, close to ‘real life’ signal conditions, show differences, then there is a reason for them sounding different. (Of course the next question is what makes them perform differently… which may or may not be easy to ascertain!) If they don’t show differences under test, but sound different, then the question becomes what are we missing? are the tests sufficiently sensitive, and/or are there other parameters that might affect sound that haven’t been tested? And also, actually the first question because validation of observation would be the first step in further investigation, are we sure they do indeed produce different sounds rather than their apparently sounding different being the result of some psychological or physiological effect/influence, and for that repeat listening tests taking steps to eliminate as far as practicable any physiological or psychological effect.

If cables do consistently test differently with audio type signals they would be expected to sound different, and if the same data were published for various cables it would enable people to focus their choice of cables to audition based on the known cable performance, still to choose on sound but not randomly as when no data are available.

If cables test differently but don’t sound different, then the effect of difference found is something not audible to the people trying in the systems used (including room) .

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I wouldn’t disagree that psychological factors can influence our perceptions. When I’m very tired or feeling under the weather my system never sounds as good.

However when I say that cable X sounds better than cable Y in my system and somebody tries to tell me that (a) cables can’t possibly sound different and (b) it is ‘expectation bias’ or some other such mumbo jumbo then I have a big problem with that.

Firstly this is a very different situation to then first example I gave, and secondly I bitterly resent somebody trying to tell me that they know what I am hearing better than I do myself. That to me is just plain stupidity and ignorance.

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I agree. If one is curious and/or has a scientific approach, that’s why one might be interested in this kind of tests and comparisons.

I don’t recall reading anyone expressing disbelief that to you, but then there are many threads and posts I’ve not followed.

“Expectation bias” and other psychological influences can be very real and by their very nature not recognised by the person affected. And influences can be in both directions: Expectation bias makes people find a positive outcome for something, whether because it costs more, or they believe sales hype etc, but people can also be influenced in other ways, such as when they hold a conviction that cables can’t make a difference, then not hearing a difference. To a greater or lesser extent these influences play on everyone, yet while some people take steps to try to minimise the risk of being influenced, others either think they’re immune or don’t care if they are so influenced because the outcome is something that, in their heads, is what they want. (From one angle that is perfectly fine as arguably it is the only thing that counts - except if they present it as fact to someone else who then takes at face value.)

One advantage of measurements finding a difference, as the subject of this thread, is that they can help people believe their ears rather than suspect they are “hearing things” (pun not intended!), or being misled, and of course help convince others who for whatever reason don’t hear a difference if/when they try.

The strange thing is that whenever I’ve tried an expensive cable or whatever I’ve always hoped that it won’t sound better - as then I won’t need to buy it. But usually it does sound better.

But, much more fundamentally, the whole question of whether someone is under the influence of expectation bias or any other psychological factor for that matter is impossible to determine in normal everyday circumstances.

You mentioned that when you auditioned your Dave DAC you were immediately convinced of it’s obvious superiority. Now that cost you an awful lot of coin. I would be fascinated to learn of what steps you took, prior to purchase, to verify to yourself that you were not in the grip of some malign and unrecognised psychological episode that was distorting your perception.

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