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post #91 of 835

@USG: They sounded different (I took 3 cables that costs around USD100). I won't go into detail how different they sound nor the brand I tried while obviously WW Starlight was one of them.

 

Hmm actually what are the so-called professional tests available out to determine whether 2 sources of sound are different? I wouldn't think frequency response graph would be appropriate though.

 

I don't like the word "audiophile cables" because they can be misleading - what if they took a USD10k snake oil cable which was marketed as "audiophile cables" and then found contradicting evidence that it instead deteriorate SQ? So shall all other USB cables be condemned?

 

 

Certainly, there are things happening around us that is hard to explain:

 

1) In spite of criticism that USB cables make no difference to SQ, no USB cable makers come out to refute that criticism.

Question: Not possible to furnish hard evidence or is it that the criticism is true?

 

2) More and more cable makers are joining the race and making expensive (touted high quality) USB cables, increasing the competition in the market.

Question: Why bother engineering and making something that is no better than stock USB cable and tarnishing their own reputation, or is it that there are simply too many rich fools out there to cheat their money? Obviously the market share for each company is shrinking due to new-entrants.


Edited by uelover - 5/20/11 at 2:48am
post #92 of 835

 

Quote:

Originally Posted by The Pell View Post

 

For those of you out there that do believe that the cable makes a difference... Wouldn't it be pretty easy to test the sonic difference by making a test audio file with different frequencies, and then setting up a mic by one of the drivers to record the audio played through each cable? Although it wouldnt be 100% scientific, I would assume that done a bunch of times, we should be able to see a difference of the waveforms of the recording.

And, for another test to check data loss.... If you were to compare the time it took to transfer a very large file several times from one drive to another using two different cables, if the cables really do make a difference, there should be consistency with the copy time of the expensive cable, and the cheap cable should have a large variance from one copy to the next. I think between those two tests, which can be done at home with a little preparation, we should have a good idea on whether or not they make a difference.

The biggest question for those that love the expensive cables, what would your response be if there was true scientific proof (beyond some minor home-based tests) that the cables truly did nothing, and the effect was psycho-somatic? And for the non-believers, what would your response be if there was true scientific proof of sonic changes?

 


- To see if the cables make an absolute difference, running a distortion analysis by sending the DAC output into a high quality ADC would be better. Mic and headphones distortions would probably dominate your results. Downside is that nobody in that discussion has the required equipment.

To see if cables make an audible difference, you'll need extensive blind testing I'm affraid. Upsides is that the equipment is easier to gather on a hifi forum.

 

- Data loss is fairly irrelevant to the discussion. The differences in sound put forward by those who claim to hear a difference in between USB cables cannot possibly come from data loss. Furthermore, your test is invalid as, in data transfer and unlike USB audio transfer, the USB bulk protocol provides for error correction. Your files will be identical no matter how cheap the cable is. There's a reason I can transfer 300go in  backup each week without losing a single bit.  biggrin.gif

 

 

I'm going to repeat myself...

 

Here are the identified possible reasons for absolute differences, they only apply to the USB audio protocols, not to the transfer mode:

 

-1- Waveform distortion: due to its physical properties, the cable can possibly affect the square waves, in interaction with the source and receiver (from that point of view they form an analog system). This in turns affect the accuracy of the recovered system clock fed to the DAC chip. This in turns affects the accuracy of the digital to analog conversion.

-2- Interaction in between power supply lines and data lines: it has been measured that 1Khz spikes coming from the data lines can couple into the power supply lines and that the longer the cable, the stronger the effect. Such spikes could maybe be directly heard as noise depending on the dac's pcb layout. Such spikes could also affect the accuracy of the ICs inside the dac, resulting either in increased jitter (for the clock or the receiver chip) or directly in higher distortion (for the dac chip and the opamps of the analog section).

-3- Rfi shielding: the usb cables are quite susceptible to high frequency noise pick-up (a reason among others why long runs cannot be used). Noise making its way into data line can perturbate the receiver chip, causing early/late triggers, resulting once again in a poorer system clock. If the noise couples into the power supply lines, see -2-.

-4- HF noise attenuation: the source computer signal's quality can vary widely. HF noise can find its way on the various USB lines. A cable attenuating this HF noise could thus have an impact. It could however interacts with -1-.

 

All these are sound engineering reasons and have been measured or could be, given time and the proper (read expensive) equipment. The fact that USB cables affect the analog output of the DAC seems to have been proven by measurements by Paul Miller for the january issue of Hifi News (if anyone has the article, I'd love to read more than hearsay).

 

HOWEVER, the existence of a technical difference in between cables does NOT prove the existence of an audible difference. It is even more so as the differences outlined above are fairly small and that cables manufacturers don't seem to bother measuring the actual differences their cables make. And you have to keep in mind before any generalization that USB audio uses 3 different protocols with various levels of weakness to those problems, that the USB receiver chips are very different and that DACs are coming from a bazillion different manufacturers who pay more or less attention to their designs.

post #93 of 835
Quote:
Originally Posted by DaBomb77766 View Post

Well, that something could just be placebo.  I'm not saying that there's necessarily anything wrong with that.  If it works for you, then I'm fine with it.  You claim to tell a difference, so I guess I'll believe you and maybe you really do find a difference.  It's just, I'm skeptical the cable itself is the thing making the difference, but until we have definitive proof either way, arguing isn't going to help anyone here.


I'm not making any claims.

 

Try the Audio DiffMaker.  See if you can get some proof.

 

post #94 of 835
Quote:
Originally Posted by 00940 View Post

-1- Waveform distortion: due to its physical properties, the cable can possibly affect the square waves, in interaction with the source and receiver (from that point of view they form an analog system). This in turns affect the accuracy of the recovered system clock fed to the DAC chip. This in turns affects the accuracy of the digital to analog conversion.

-2- Interaction in between power supply lines and data lines: it has been measured that 1Khz spikes coming from the data lines can couple into the power supply lines and that the longer the cable, the stronger the effect. Such spikes could maybe be directly heard as noise depending on the dac's pcb layout. Such spikes could also affect the accuracy of the ICs inside the dac, resulting either in increased jitter (for the clock or the receiver chip) or directly in higher distortion (for the dac chip and the opamps of the analog section).

-3- Rfi shielding: the usb cables are quite susceptible to high frequency noise pick-up (a reason among others why long runs cannot be used). Noise making its way into data line can perturbate the receiver chip, causing early/late triggers, resulting once again in a poorer system clock. If the noise couples into the power supply lines, see -2-.

-4- HF noise attenuation: the source computer signal's quality can vary widely. HF noise can find its way on the various USB lines. A cable attenuating this HF noise could thus have an impact. It could however interacts with -1-.

 

All these are sound engineering reasons and have been measured or could be, given time and the proper (read expensive) equipment. The fact that USB cables affect the analog output of the DAC seems to have been proven by measurements by Paul Miller for the january issue of Hifi News (if anyone has the article, I'd love to read more than hearsay).

 

HOWEVER, the existence of a technical difference in between cables does NOT prove the existence of an audible difference. It is even more so as the differences outlined above are fairly small and that cables manufacturers don't seem to bother measuring the actual differences their cables make. And you have to keep in mind before any generalization that USB audio uses 3 different protocols with various levels of weakness to those problems, that the USB receiver chips are very different and that DACs are coming from a bazillion different manufacturers who pay more or less attention to their designs.


Thsnks so much for posting this.  I couldn't agree more.

 

post #95 of 835
Quote:
Originally Posted by 00940 View Post

 

 

- Data loss is fairly irrelevant to the discussion. The differences in sound put forward by those who claim to hear a difference in between USB cables cannot possibly come from data loss. Furthermore, your test is invalid as, in data transfer and unlike USB audio transfer, the USB bulk protocol provides for error correction. Your files will be identical no matter how cheap the cable is. There's a reason I can transfer 300go in  backup each week without losing a single bit.  biggrin.gif

 

 


Im not testing file size, I would test transfer time. If there is way more error correction going on with a cheaper cable, the file transfer would take longer.

 

post #96 of 835

http://www.passmark.com/products/usb2loopback.htm

 

You could try something like this, but it's still extremely imprecise to use such a method it since the problem could come more from the PC you're using than the cable itself.  Still, if there's a drastic difference from one USB cable to another, especially if the so-called "audiophile" cables have less error correction, then it would be interesting.

 

At any rate, testing error correction rates based on transfer times would be kind of ridiculous.  You'd have to have a perfectly neutral testbed with absolutely nothing running in the background, and only the USB service and filesystem up and running.  Otherwise other services or programs running in the background could significantly skew the results.

post #97 of 835

I NEED to hop in here! I am somewhat new to Headfi, it being a 5month old hobby for me, but I have spent about 3000$ on Headphone equipment and a soundcard for kicks. (1800 after I returned wires). I traveled to the 4 largest audio shops in my STATE (for fun) just to demo new (pretty much every modern) incredibly expensive product of all kinds with headphones I've demoed a grand total of probably somewhere around 20 aftermarket cables.

 

Midway through this journey about 2 1/2 months ago, I spent $1200-1400 on signal cables (this does not including Headphone my $580 of headphone recabling, source cable only) of all colors, shapes and forms. -EDIT: for post coherence reasons I've refrained from listing the plethora-.

 

NOW, I too was skeptical to begin with, "A cable?!!? Really? How's that going to improve my experience?!"

 

I'm here to tell you that ALTHOUGH "It's just 1's and 0's" This does NOT hold true for audio the same way it does for video. 00940's post = angelic sending concerning this topic and explains (most) of the science behind it. This is a myth that needs to be dispelled - BADLY. Anyone who tries to play Dr. Phil with the "cable believers vs nonbelievers" argument has very obviously never, ever...EVER tried a third party cable of any sorts, and they are denying their real systems potential.

 

Ask anyone and I do mean anybody who personally own a 2k+ rig built around 1-2 headphone, anybody who builds chips for a living, anybody who's heard credible (not dirt cheap) aftermarket cables. The difference is astounding, no buts about it: the difference can easily be ASTRONOMICAL!!!!!!!!!!!

Without Custom cabling Headphones lose their edge to speakers... It's a sad truth, but Custom cabling allows Headphones to be taken to a whole new level, and THAT is where the true bang for buck sound is in headphones. I would vehemently "reasonably debate" with any cable "nonbeliever" *cough, *cough*

 

If you do NOT (LOOOLL) believe me then please, by all means, TRY IT! Signal cable is JUST AS important as what DAC, amp, or source you choose, and I do mean JUST AS imporant. Sadly recabling is terribly underrated, heh, accept by those who've actually tried or done it. Everyone else who has had the opportunity..... is terribly naiive to the level of performance their system could have. It really is terribly sad and somebody needs to set the record straight.

 

That "believer vs non-believer" argument is blasphemous  unto the audio religion itself. If you are devoted to the sound, don't you think you owe it to yourself to at least try it out and discern with your own ears?!?!?!?!?!?!?!?!? OF COURSE you do! So get out there and TRY IT. If you don't like it then just RETURN it. (pew pew) biggrin.gif I hope this incredibly passionate rant was somewhat informative and can lay to rest the cable questions. (I am sick of seeing cable "makes difference or no" questions).

 

I could go on to describe every cable as I heard it, but that would be boring (EDIT: to me popcorn.gif) and almost pointless. It's too nitty-gritty to post that many reccomendations online. Cabling is just one of those things you have to try out for yourself. I will say that USB signal cable has come LEAPS and BOUNDS in the last year or so, and it is widely believed among those in the industry that the new offerings do match and even surpass the traditional "coax is supreme" cable at a fraction of the price. It's also quite a lot cheaper than coax of similar quality (i.e. 500$ usb cable = about 680-800$ coax cable, and it still edges those coax cables out.... and Glass fiber?! Don't even go there for headphones. 550-700$ per cable that don't even take the signal off your digital passthroughs clock? That's one of USB's two strengths(!!!!) Count me out when such things exsist as the Carbon, Coffee, and Diamond Audioquest USB cables. Wireworld also makes (from what I've heard good cables that sell too.

Audioquest really put some effort into their 2 high end USB's. TRY CARBON usb if you're curious about aftermarket signal cable, hell or even cinnemon would float your boat into new waters, but I've found carbon be the best bang (incuding dollar for performance) for buck regarding any setup or chain. Kimber Cable also makes two Great usb cables) Theirs are solid copper and 6.25% plated silver.

 

Overall in short, the best 2 cables to my ears (and also 2nd and 3rd opinion freinds who had no vested interest in the purchases whatsoever) were the Diamond and Coffee USB cables by Audioquest. Yes, it's a lot to sink into a cable, but please, please, at least educate yourself by giving products like them a shot. Your ears DO NOT deserve to live in darkness. Not with all the money you've already poured into your setup desperately searching for the best sound. Cables are one of the main strengths that make headphones what they are: in a word, EPIC joy. ;*)beerchug.gif

 


Edited by Hennyo - 5/24/11 at 8:06pm
post #98 of 835

I am 18, I am by no means rich, and have lived on my own for the last 3 years. I am just devoted to absolute excellence in whatever I'm interested in/wish to pursue. ^^

post #99 of 835
Quote:
Originally Posted by DaBomb77766 View Post

http://www.passmark.com/products/usb2loopback.htm

 

You could try something like this, but it's still extremely imprecise to use such a method it since the problem could come more from the PC you're using than the cable itself.  Still, if there's a drastic difference from one USB cable to another, especially if the so-called "audiophile" cables have less error correction, then it would be interesting.

 

At any rate, testing error correction rates based on transfer times would be kind of ridiculous.  You'd have to have a perfectly neutral testbed with absolutely nothing running in the background, and only the USB service and filesystem up and running.  Otherwise other services or programs running in the background could significantly skew the results.


re: error correction rates...

Only bulk mode devices (musiland seems to be the only one I know to use it for audio) actually do both error detection and correction. (crc-ish + 'ltd hardware' retransmission and data delivery guarantee, but not latency guarantee). Technically it seems to be an overlay 'bus' they use to ship the data over to the device and then feed the reconstructed data to the DAC chip. Latency is 'technically' not guaranteed, but there should usually be enough bandwidth?

Neither sync, async or adaptive mode usb audio devices seem to. These all have a 'guaranteed latency', but as a result, no retransmission (have a look at the usb spec docs http://www.usb.org/developers/docs/usb_20_021411.zip usb20 pdf sec 4.7)

(errr, might have error detection - bit parity of some sort or whatever else, but no retransmission)
Quote:
The timely delivery of isochronous data is ensured at the expense of potential transient losses in the data
stream. In other words, any error in electrical transmission is not corrected by hardware mechanisms such
as retries. In practice, the core bit error rate of the USB is expected to be small enough not to be an issue.

I really wonder if the more expensive 'audiophile' cables even conform to the USB specs standards biggrin.gif...So yes, good point about the possibility of it measuring worse... A good starting point might be seeing whether they conform to those standards first biggrin.gif
I'm sure the product makers will then market it the cables as warm and fuzzy and unique biggrin.gif. The errors make the sound analog and natural biggrin.gif...




>I am 18, I am by no means rich, and have lived on my own for the last 3 years. I am just devoted to absolute excellence in whatever I'm interested in/wish to pursue. ^^

I see a shiny power and usb cable in your future biggrin.gif
Edited by svyr - 5/20/11 at 9:54am
post #100 of 835

I'm just gonna ignore Hennyo and pretend he never posted.

 

Anyway, for "true" audiophlie usages, I see no reason why latency should be any issue whatsoever.  Error correction and retransmission would absolutely fix every problem there is to do with packet loss in the cable.  If they introduce a fraction of a second of lag, it's not going to make any effect on audio quality whatsoever, at least when you're only listening to music, and the error correction will simply remove the cable as a source of errors.  I see no reason why this wouldn't work.  If I can transfer my entire 32GB audio library to an external hard drive without any corruption of the files, then the same should be said for USB transmission of audio to a DAC.

 

There must be some reason why this hasn't been done before though.  If anyone knows, feel free to tell me.

post #101 of 835
Quote:
Originally Posted by DaBomb77766 View Post

I'm just gonna ignore Hennyo and pretend he never posted.

 

Anyway, for "true" audiophlie usages, I see no reason why latency should be any issue whatsoever.  Error correction and retransmission would absolutely fix every problem there is to do with packet loss in the cable.  If they introduce a fraction of a second of lag, it's not going to make any effect on audio quality whatsoever, at least when you're only listening to music, and the error correction will simply remove the cable as a source of errors.  I see no reason why this wouldn't work.  If I can transfer my entire 32GB audio library to an external hard drive without any corruption of the files, then the same should be said for USB transmission of audio to a DAC.

 

There must be some reason why this hasn't been done before though.  If anyone knows, feel free to tell me.


yea I'm an under an impression that there's more than enough bandwidth for the bulk mode devices to do the retransmission and that they're actually preferable over isochronous USB ones.. And yes it should make the cable a non-issue as long as it's not bad enough to do something like let's say 2x the audio bandwidth (a lot less than the USB 2 spec anyway biggrin.gif not to mention if the loss rate is so high, using that on an isochronous device instead will probably be heavily audible since there's no error correction there) (For bulk mode audio, like musilol, since it's playback and not recording, the latency is a non-issue for me too. In any case, there won't be a drop out unless the bulk data buffer is empty (probably IO or CPU resources unavailable, and those conditions will most like would cause isochronous devices to also drop samples)).

The problem is, I literally have only seen it on the musiland devices ... and um, MD11 was by no means otherwise lovely biggrin.gif (their QC for software and hardware seems to be 'this probably looks good, so lets make 100s of units and make people download 100s of copies of this driver/firmware that doesn't actually install/has channels reversed but it's probably all bit perfect and great' biggrin.gif )...
Edited by svyr - 5/20/11 at 10:43am
post #102 of 835


 

Quote:
Originally Posted by uelover View Post

@USG: They sounded different (I took 3 cables that costs around USD100). I won't go into detail how different they sound nor the brand I tried while obviously WW Starlight was one of them.

 

Hmm actually what are the so-called professional tests available out to determine whether 2 sources of sound are different? I wouldn't think frequency response graph would be appropriate though.

 

I don't like the word "audiophile cables" because they can be misleading - what if they took a USD10k snake oil cable which was marketed as "audiophile cables" and then found contradicting evidence that it instead deteriorate SQ? So shall all other USB cables be condemned?

 

 

Certainly, there are things happening around us that is hard to explain:

 

1) In spite of criticism that USB cables make no difference to SQ, no USB cable makers come out to refute that criticism.

Question: Not possible to furnish hard evidence or is it that the criticism is true?

 

2) More and more cable makers are joining the race and making expensive (touted high quality) USB cables, increasing the competition in the market.

Question: Why bother engineering and making something that is no better than stock USB cable and tarnishing their own reputation, or is it that there are simply too many rich fools out there to cheat their money? Obviously the market share for each company is shrinking due to new-entrants.

 

 

I won't go into detail how different they sound nor the brand I tried


I'd love to hear the details.

 

what are the so-called professional tests available out to determine whether 2 sources of sound are different......

 

Although Nick_Charles informed me that it can generate some false positives, the Audio DiffMaker, that Prog Rock Man posted about, is probably the easiest tool to use.  You record a WAV with one usb cable or interconnect in place, then change cables and record the same thing again.  The program nulls out everything that is the same and you are left with only the differences.  All the usual questions are covered on their web site.

 

A few years ago I was under the impression that I could tell the difference, in my M^3, between an 8610 oamp and a 637/627.  I e-mailed AMB about this and he told me that they would sound the same in an M^3.  Unconvinced, I sent him a WAV of each opamp to demonstrate the differences I clearly could hear.  He put the stereo streams into audacity and turned each one into mono.  Then he took the 2 mono streams and made a new stereo stream.  Now he inverted 1 of the streams and lined them up by eye.  The result was a -45dB WAV of the difference between the 2 WAVs, I sent him.  The verdict:  Any difference between those 2 opamps was inaudible.

 

I may not have gotten all AMB's steps right, but now we have the Audio DiffMaker that does the same thing for us automatically.

 

Certainly, there are things happening around us that is hard to explain:

 

1) In spite of criticism that USB cables make no difference to SQ, no USB cable makers come out to refute that criticism.

Question: Not possible to furnish hard evidence or is it that the criticism is true?

 

Here is an opportunity for those who have high end cables to begin to generate some data showing that differences exist, or not if they don't.   I think that we can agree that any data that can show differences is better than the absolutely no data situation that exists now.  Another advantage is that these results should be relatively reproducible.  If you find a notable difference between the Starlight cable and the one it replaced, others should be able to get similar results with that cable.

 

Here's what you need.  A cable of your choice that goes from the headphone output of your amp to the mic input of your computer.  If you only have a laptop you might need a usb mic input for stereo recording.  And of course, some high quality cables to test.

 

Here is the cable I used.

 

IMG_2984 600.jpg


Edited by upstateguy - 5/20/11 at 11:22am
post #103 of 835
Quote:
Originally Posted by DaBomb77766 View Post

I'm just gonna ignore Hennyo and pretend he never posted.

 

Anyway, for "true" audiophlie usages, I see no reason why latency should be any issue whatsoever.  Error correction and retransmission would absolutely fix every problem there is to do with packet loss in the cable.  If they introduce a fraction of a second of lag, it's not going to make any effect on audio quality whatsoever, at least when you're only listening to music, and the error correction will simply remove the cable as a source of errors.  I see no reason why this wouldn't work.  If I can transfer my entire 32GB audio library to an external hard drive without any corruption of the files, then the same should be said for USB transmission of audio to a DAC.

 

There must be some reason why this hasn't been done before though.  If anyone knows, feel free to tell me.

 

I think there might be a difference between the data stream sent to your external HD and the PCM stream sent to your dac. 

 

Someone with better knowledge please chime in and clear this up.
 

 

post #104 of 835

If USB cables failed to transmit audio data uncorrupted would the result be -

 

A - poorer sound quality

 

B - the sound cutting out, crackles, pops

 

as the signal has not arrived as it should be?

 

I think the answer is B as how could corrupted data affect clarity, bass, treble as that would suggest the error is only one part and consistently one part of the data stream. Any corruption would affect the whole signal either for a short period of time, so possibly causing a crackle, or longer so cutting out the sound altogether.

 

 

 

 

post #105 of 835

People perceive a difference due to cognitive bias and visual cues.

When someone actually blind tests a set of usb cables and can actually hear a difference between a £0.99 cable and a £60+ cable,

Then and only then will I rethink my cable skepticism. 

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