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Is it possible to improve the USB as a cable for audio purposes? - Page 5

post #61 of 93

Fancy USB cables sounds like a good thing to test at Head-fi meets.

 

It makes sense to have a look at the audio standard documents at USB.org. 

 

Obviously wireless USB doesn't get improved by a cable.

post #62 of 93
Quote:
Originally Posted by Caution View Post

 

Sorry... But have you looked at how USB audio is transferred? Transferring data from a HDD and transferring audio over USB use 2 completely different transfer protocols. One has error correction, the other doesn't, one is time sensitive, one is time insensitive, one has guaranteed retransmission, the other doesn't. Have a guess which one is which. I'm not sure how this goes against science and engineering concepts...

 

I don't have to - the protocol is designed with the assumption you are using a USB cable that meets the USB standard, thus that "cable" factor is irrelevant to the protocol in the first place.  If the cable is standard compliant then it works, if it is not, then the entire system breaks.  It's simple as that.

 

Also I don't have to look at your example either - I majored in telecommunication engineering in uni, I know what digital processing is and how it works.  Not a square wave on the other end?  Do you really think you are the first person to think of this problem and you are smarter than all of the engineers, scientists and mathematicians who compiled all the DSP theories/laws together from which we have all these computer gadgets and telecommunication equipment we use now?  Hint: NO, it's basic digital signal theory and the idea is preciously build on this idea that you can ignore imperfection like these and the whole point why digital is superior to analog due to its huge tolerance to error, noise and analog signal transfer imperfection.


Edited by nanaholic - 1/30/13 at 11:50pm
post #63 of 93

Heh, like I said earlier, these threads always end up in a pointless war between 2 sides that have strong opinions. People who have tried and can hear a difference, and people who haven't tried due to their confidence in infallible theoretical knowledge that always hold true in the real world.

 

As mentioned before, I think it's good to approach this hobby with an open mind. Trying another USB cable isn't hard, and in the grand scheme of things won't cost a lot of money.

post #64 of 93
Quote:
Originally Posted by Caution View Post

Heh, like I said earlier, these threads always end up in a pointless war between 2 sides that have strong opinions. People who have tried and can hear a difference, and people who haven't tried due to their confidence in infallible theoretical knowledge that always hold true in the real world.

 

As mentioned before, I think it's good to approach this hobby with an open mind. 

 

The same can be said for religion and science. Guess which one makes your music work?

post #65 of 93
Quote:
Originally Posted by Caution View Post

Heh, like I said earlier, these threads always end up in a pointless war between 2 sides that have strong opinions. People who have tried and can hear a difference, and people who haven't tried due to their confidence in infallible theoretical knowledge that always hold true in the real world.

 

As mentioned before, I think it's good to approach this hobby with an open mind. Trying another USB cable isn't hard, and in the grand scheme of things won't cost a lot of money.


You still haven't answered my question btw. I responded to your post with a reasonable answer, I expect the same from anyone who wants to have a fruitful discussion.


Edited by proton007 - 1/31/13 at 1:39am
post #66 of 93
Quote:
Originally Posted by Caution View Post

Sorry... But have you looked at how USB audio is transferred? Transferring data from a HDD and transferring audio over USB use 2 completely different transfer protocols. One has error correction, the other doesn't, one is time sensitive, one is time insensitive, one has guaranteed retransmission, the other doesn't. Have a guess which one is which. I'm not sure how this goes against science and engineering concepts... Read below

Okay, so here's an example. Let's say you have a cheap cable with less then adequate shielding between the data and power lines, It's a well know fact USB power from a computer is dirty (or are we going to deny this too?), what happens if you put these 4 lines together in a cable? Will they not interact and impact each other? What happens with the square wave that is being sent through the cable? Chances are the square wave won't look the same when it reaches an end point (your dac) as it did from your PC.

The digital signal is actually carried in an analog format represented as 1s and 0s, it's not some voodoo magic binary medium that is infallible to alteration.
Digital cables aren't a voodoo magic medium infallible to alteration, but they aren't a voodoo magic medium capable of decoding digital audio either.

What a cable sees is something like 01000100101010101010010110011100. Do you really think that a cable is smart enough to figure out that every block of 16 bits is a number and that these numbers are amplitude of some wave changing over time? Does it know how to slightly affect these numbers (what may involve changing anything from a single bit to all of them, e.g 1000+1=1001, but 0111+1 = 1000. Does it know how to change a very long sequence of these numbers to remove some remove high frequencies? What about low frequencies? Maybe increasing decay time of some sounds?

These are all claims made by "USB cable guys" and they make completely no sense. If your DAC disconnects from the bus, it may be the cable. If your DAC drops fragments of audio, it may be the cable. If your DAC plays some completely random garbage every now and then, it may be the cable. But "details", "clarity" or "bass impact" have nothing to do with cables.
post #67 of 93
Quote:
Originally Posted by proton007 View Post

The same can be said for religion and science. Guess which one makes your music work?
The former has often been a strong force driving music development.

Maybe you meant "sound reproduction" instead of "music"?
post #68 of 93
Quote:
Originally Posted by Caution View Post

Heh, like I said earlier, these threads always end up in a pointless war between 2 sides that have strong opinions.

 

Sorry but this is simply not true, there are no 2 opinions here - only 1 opinion (cable believers with anedoctoal evidence which btw is not consider good scientific evidence), the other is a set of facts backed up by scientific eivdences and real world applications in many sectors, including the very computer and the internet you are reading this message on. 

 

Also I suspect you belong to the "just a theory" group of people like creationists denying evolution - here's a tip for you, a scientific theory doesn't mean "it's a wild guess I pulled out of my rear" but an explaination which explains a set of facts.  Again this has nothing to do with being open-minded, just like you don't have to be open-minded to silly claims like the Earth is flat.

post #69 of 93
Quote:
Originally Posted by Caution View Post

Heh, like I said earlier, these threads always end up in a pointless war between 2 sides that have strong opinions. People who have tried and can hear a difference, and people who haven't tried due to their confidence in infallible theoretical knowledge that always hold true in the real world.

 

As mentioned before, I think it's good to approach this hobby with an open mind. Trying another USB cable isn't hard, and in the grand scheme of things won't cost a lot of money.

 

I think I just posted that I have tried many different vendor USB cables, and I did not hear any difference.

 

If you did then that is great. Other than "I can hear a difference", what did your top USB cable did better than the rest in terms of "real world" signal integrity and performance.

 

Furthermore, do you think measuring bit error rate when qualifying if a bunch of 1's and 0's make it from point A to point B through different USB cables is a "theoretical" evaluation, or a "real world" evaluation?

post #70 of 93
Quote:
Originally Posted by Caution View Post

Heh, like I said earlier, these threads always end up in a pointless war between 2 sides that have strong opinions. People who have tried and can hear a difference, and people who haven't tried due to their confidence in infallible theoretical knowledge that always hold true in the real world.

 

As mentioned before, I think it's good to approach this hobby with an open mind. Trying another USB cable isn't hard, and in the grand scheme of things won't cost a lot of money.

Aaaaaand back to just re-stating your original claim after everything you have said has been countered.

 

This is going nowhere guys. He's just here to spew out his baseless opinion, not learn anything.

post #71 of 93
Quote:
Originally Posted by Caution View Post

I'd be interested to see how many people here who claim USB cables don't make a difference have actually tried a variety of cables from different price ranges in a revealing system. I doubt many...

 

I'd be interested to see people who claim different USB cables make a difference to demonstrate this in double blind listening tests.

 

The problem we have is that people are reporting differences, but they do not understand the very great power that suggestion and autosuggestion have in hearing.

 

I do have an article on this subject which I've linked to in my signature. I have done this so I don't have to keep writing the same stuff over and over.

post #72 of 93
Quote:
Originally Posted by Caution View Post

Heh, like I said earlier, these threads always end up in a pointless war between 2 sides that have strong opinions. People who have tried and can hear a difference, and people who haven't tried due to their confidence in infallible theoretical knowledge that always hold true in the real world.

 

As mentioned before, I think it's good to approach this hobby with an open mind. Trying another USB cable isn't hard, and in the grand scheme of things won't cost a lot of money.

 

You write about "People who have tried and can hear a difference", but was this in a double blind listening test?

 

I think you dramatically underestimate the power of suggestion and autosuggestion.

 

In the last decade tremendous research has been carried out in human hearing which illustrates the extremely flexible way in which our hearing perceives sounds.

 

I think you should develop an open mind to the possibility that when you listen to music through audio systems then your evaluation of those systems or indeed any components within them is always going to include a huge element of influence from suggestion and autosuggestion. The only way to combat this is to assess in double blind listening tests.

post #73 of 93
Quote:
Originally Posted by proton007 View Post

 

The same can be said for religion and science. Guess which one makes your music work?

 

Um, not sure how you can compare what I said with religion and science... They are on 2 different scales, but obviously the answer to your question is science.

 

 

Quote:
Originally Posted by nanaholic View Post

 

Sorry but this is simply not true, there are no 2 opinions here - only 1 opinion (cable believers with anedoctoal evidence which btw is not consider good scientific evidence), the other is a set of facts backed up by scientific eivdences and real world applications in many sectors, including the very computer and the internet you are reading this message on. 

 

Also I suspect you belong to the "just a theory" group of people like creationists denying evolution - here's a tip for you, a scientific theory doesn't mean "it's a wild guess I pulled out of my rear" but an explaination which explains a set of facts.  Again this has nothing to do with being open-minded, just like you don't have to be open-minded to silly claims like the Earth is flat.

 

 

 

I'm also a scientific believer and was a sceptic of USB cables, however my "real world" observation produced unexpected results. Also, as you may know scientific evidence does not always produce absolute proof. Lack of scientific proof doesn't mean something can not occur. Let's flip the coin here, has there been any scientific evidence to prove that USB cables don't make a difference? No... Well then you're probably going to say, well it doesn't need to be proved because the answer is obviously no, it's digital you idort... There's either a signal or there isn't. Well maybe it seems simply black and white because the complexity has been abstracted by the engineers who design dacs and have already accounted for this, and thus the dac has high tolerance due to approximation for less than ideal square waves in order to prevent drop outs? How can you be so sure the signal is not interacting with the material and construction of the cable to alter the wave in a way that the dac needs to do a less than ideal approximation in isochronuos mode transfer? 

 

Also, I'm an atheist thanks for asking ;)

 

 

Quote:
Originally Posted by ultrabike View Post

 

I think I just posted that I have tried many different vendor USB cables, and I did not hear any difference.

 

If you did then that is great. Other than "I can hear a difference", what did your top USB cable did better than the rest in terms of "real world" signal integrity and performance.

 

Furthermore, do you think measuring bit error rate when qualifying if a bunch of 1's and 0's make it from point A to point B through different USB cables is a "theoretical" evaluation, or a "real world" evaluation?

 

 

All those cables you listed have a similar generic construction, which I agree with you and think they sound the same. The cables that sound noticeably different are the ones where the power and data lines are separated (This is why I said cables in differing price ranges as these are usually more expensive). No, it's not my eyes that deceive me, I don't think they sound different because they look better. My "best looking" after market cable actually induces simbilance and physically hurts to listen to, I do not get this with any other cable. Note: I have never mentioned anything about "improvements" in this thread, only differences.

 

To answer your question, I'd say both.

 

 

Quote:
Originally Posted by mich41 View Post


Digital cables aren't a voodoo magic medium infallible to alteration, but they aren't a voodoo magic medium capable of decoding digital audio either.

What a cable sees is something like 01000100101010101010010110011100. Do you really think that a cable is smart enough to figure out that every block of 16 bits is a number and that these numbers are amplitude of some wave changing over time? Does it know how to slightly affect these numbers (what may involve changing anything from a single bit to all of them, e.g 1000+1=1001, but 0111+1 = 1000. Does it know how to change a very long sequence of these numbers to remove some remove high frequencies? What about low frequencies? Maybe increasing decay time of some sounds?

These are all claims made by "USB cable guys" and they make completely no sense. If your DAC disconnects from the bus, it may be the cable. If your DAC drops fragments of audio, it may be the cable. If your DAC plays some completely random garbage every now and then, it may be the cable. But "details", "clarity" or "bass impact" have nothing to do with cables.
 
 

 

Like I said, binary digits are used as a simplistic model to help explain digital to the mass, it's obviously worked very well ask your mom or dad or even grandma how digital works. Chances are they will say 10101011! Well It's not literally 1s and 0s. Remember doing science in high school being taught something in class, only to go to uni to find out everything you have been taught is an oversimplification and is far from the truth?

 

I never said anything about usb cables decoding digital audio, I'm not sure where you got that from. What I'm talking about is signal integrity.Square waves in reality are not always perfect like you see in a text book, It's in analog form and therefore susceptible to alteration just like any other analog wave form, your DAC (and the engineers who designed the DAC) on the other hand is pretty smart and is able to approximate and interpret less than ideal signals it receives. 

 

I hope what I have written above has answered your question proton007.

post #74 of 93
Quote:
Originally Posted by p a t r i c k View Post

 

You write about "People who have tried and can hear a difference", but was this in a double blind listening test?

 

I think you dramatically underestimate the power of suggestion and autosuggestion.

 

In the last decade tremendous research has been carried out in human hearing which illustrates the extremely flexible way in which our hearing perceives sounds.

 

I think you should develop an open mind to the possibility that when you listen to music through audio systems then your evaluation of those systems or indeed any components within them is always going to include a huge element of influence from suggestion and autosuggestion. The only way to combat this is to assess in double blind listening tests.

 

Yes I completely agree with double blind testing, and will do this in the future.

 

However a couple of points as mentioned in my previous post, one of my cables is actually pretty painful to listen to (physically), I'm not sure if auto suggestion can be huge enough to account for this... This had nothing to do with volume matching as the cable was used in an a/b test, and also kept in my system for a couple of days.


Edited by Caution - 1/31/13 at 10:13pm
post #75 of 93
Quote:
Originally Posted by Caution View Post

 

Like I said, binary digits are used as a simplistic model to help explain digital to the mass, it's obviously worked very well ask your mom or dad or even grandma how digital works. Chances are they will say 10101011! Well It's not literally 1s and 0s. Remember doing science in high school being taught something in class, only to go to uni to find out everything you have been taught is an oversimplification and is far from the truth?

 

I never said anything about usb cables decoding digital audio, I'm not sure where you got that from. What I'm talking about is signal integrity.Square waves in reality are not always perfect like you see in a text book, It's in analog form and therefore susceptible to alteration just like any other analog wave form, your DAC (and the engineers who designed the DAC) on the other hand is pretty smart and is able to approximate and interpret less than ideal signals it receives. 

 

I hope what I have written above has answered your question proton007.


Let me provide the definition of a digital signal:

 

 

In computer architecture and other digital systems, a waveform that switches between two voltage levels representing the two states of a Boolean value (0 and 1) is referred to as a digital signal, even though it is an analog voltage waveform, since it is interpreted in terms of only two levels. Logic changes are triggered either by the rising edge or the falling edge.

 

I'm still not sure what you don't understand. It doesn't matter what the signal looks like, as long as it switches between levels at regular intervals.

If it doesn't switch properly, the data is wrong. Pure and simple. And if a cable is capable of doing this, it means it won't work for *any* form of USB transfer.

 

Also, engineers don't approximate anything in logic levels. They use a Schmitt Trigger. Approximation would never work with digital signals.

Talking about asynchronous usb transfer mode, it may skip frames, because of a buffer issue (with your PC etc), but the cable still has no role to play here.

 

And judging by your response, it seems like you haven't seen a digital signal on an oscilloscope, and your knowledge on digital processing also seems to be lacking. Digital signals are never purely square, because they don't need to be, long as they meet a certain transition (rise/fall) time (which again, doesn't depend on the cable).

 

I hope you really do some reading up on this. Otherwise it'll be hard to take you seriously.


Edited by proton007 - 1/31/13 at 10:40pm
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