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Dilemma: Should I not believe any reviewers who talk about cables or just ignore that section of... - Page 114

post #1696 of 1790

I asked earlier if Wireworld has an explanation.  I looked and they don't have any that are convincing to me.  They do have a page showing what they say is waveform error for generic USB vs theirs. 

 

http://wireworldcable.com/Image_Library.html  Look at the January 2013 white paper under "product sheets".

 

Here they say they played a music waveform through one cable and then differenced it against their USB cabled.  I am assuming they recorded the result and subtracted one waveform from another.  Just happens I spent some time doing just that with USB, and analog cables a bit over a year ago.  I still have the files.  Here is a screenshot of my result. 

 

One file was a 96 khz recording of a Clark Terry song using a friend's Wireworld USB (was either Ultraviolet or Starlight didn't record which).  Then again using a 33 foot monoprice USB extender the end of which was using a generic USB cable that came in an HP printer.   I even changed the scale to match what Wireworld has best I could tell.  They appeared to have it at 25%.  Even if I zoomed in like their second picture it looks like a flat line.  Zoomed in 5 times closer it looks a bit fuzzy.   This isn't a zero.  Doing the FFT on it, there is a peak of -107 db at 60 hz.  Everywhere else is around -115db to 118 db.  That is the basic noise level of the equipment on hand.  Later with quieter equipment got the same result between USB cables just the noise floor was lower by 8-10 decibels.  I didn't have the Wireworld on hand at that later time.

 

As there appears to be no difference greater than -100 db I dont' know how you could hear that.  I also don't know the details of why they show a different result.  I had only good consumer level equipment yet get far better performance than they are showing.


Edited by esldude - 7/11/13 at 9:32pm
post #1697 of 1790
I would think that when you hear a difference where there really shouldn't be a difference, you'd be interested in finding out why. When I compare equipment, I want to know *why* something sounds better than something else. If I don't understand that, how am I going to continue to improve my system? Just plain old luck is too slow. I only have a lifespan of a normal human being. (and hearing to match!)
post #1698 of 1790
http://www.wireworldcable.com/categories/usb_cables.html

You guys are correct. Data transfer is free of timing issues.

This is from Wireworld

There is a fundamental difference between the transfer of computer data and USB crossection
digital audio signals. Computers are able to transfer digital data without loss, because the data moves in the robust form of blocks, which do not depend on specific timing between the sending and receiving devices. However, digital audio signals are continuous streams of data, which are quite fragile, since the digital processor must remain perfectly locked onto the timing of the signal to avoid data losses.
The Limitations of digital audio processors and cables create timing errors known as jitter, which remove portions of the audio signal and replace them with noise and distortion. Cables tend to round off the square waveforms of the signal, making them less clear to the processor, thus increasing jitter. This rounding effect varies greatly among cables and a truly superior digital audio cable can make great improvements in sound quality.
WireWorld digital audio cables utilize unique designs specifically developed to minimize jitter by providing sharper, cleaner leading edges on the digital waveform.
post #1699 of 1790
What is wireworld? A company that sells high end cables?

Because I know about jitter, and it isn't a problem because the DAC has a buffer that makes sure the digital stream goes through smoothly. Jitter as it occurs in even the cheapest digital audio equipment is as much as 100 times below the threshold of audibility.

This has been discussed extensively here. You've been around for a long time. I'm sure you've read about all this stuff before.

What's wrong with doing a controlled blind listening test? It isn't that hard really. I think they're kind of fun.

.
Edited by bigshot - 7/11/13 at 8:54pm
post #1700 of 1790
Do I have a choice? I want to know as well but I think it would be more about my audio memory ability. But I can and will give er a spin with another head fier in the near future. Argh......
post #1701 of 1790
The nice thing about blind tests is you know for sure if there is a difference you can really hear. If not... you just saved a bunch of money!
post #1702 of 1790
Quote:
Originally Posted by Happy Camper View Post

http://www.wireworldcable.com/categories/usb_cables.html

You guys are correct. Data transfer is free of timing issues.

This is from Wireworld

There is a fundamental difference between the transfer of computer data and USB crossection
digital audio signals. Computers are able to transfer digital data without loss, because the data moves in the robust form of blocks, which do not depend on specific timing between the sending and receiving devices. However, digital audio signals are continuous streams of data, which are quite fragile, since the digital processor must remain perfectly locked onto the timing of the signal to avoid data losses.
The Limitations of digital audio processors and cables create timing errors known as jitter, which remove portions of the audio signal and replace them with noise and distortion. Cables tend to round off the square waveforms of the signal, making them less clear to the processor, thus increasing jitter. This rounding effect varies greatly among cables and a truly superior digital audio cable can make great improvements in sound quality.
WireWorld digital audio cables utilize unique designs specifically developed to minimize jitter by providing sharper, cleaner leading edges on the digital waveform.

 

Even usb audio is sent in packets, not as a continuous stream of bits. Using my google-fu, I've identified a more in depth article on how usb audio is implemented. Be sure to read the 2nd and 3rd pages as well!

 

Only the poorest of designs (or most outdated!) have any dependance on timing cues from the computer. Modern DACs operate in asynchronous mode, where the DAC asks the computer to send data packets when the DAC is ready for it. The actual clocking of the conversion of bytes to audio happen within the DAC using its own (and hopefully sufficiently stable!) clock. There is simply no mechanism for jitter from the computer or the usb cable to affect the output jitter of a modern asynchronous DAC. Any defect in the data stream is because one of the components in the chain (CPU->USB port->cable->USB port->DAC) is operating outside of specification and should be considered broken. All USB cables which meet the USB standard transfer data equally well.

 

Somewhat ironically, the only device that could even be argued to potentially benefit from a fancy USB cable would be one of exceedingly poor design and quality. You're better off spending money on a modern asynchronous DAC (like a $99 Modi---and I'm sure there are cheaper, too) than buying wireworld USB cables (of which the cheapest 1-meter cable is ~ $80 USD).

 

Hope this helps!

Cheers!

post #1703 of 1790
Quote:
Originally Posted by ab initio View Post

 

Even usb audio is sent in packets, not as a continuous stream of bits. Using my google-fu, I've identified a more in depth article on how usb audio is implemented. Be sure to read the 2nd and 3rd pages as well!

 

Only the poorest of designs (or most outdated!) have any dependance on timing cues from the computer. Modern DACs operate in asynchronous mode, where the DAC asks the computer to send data packets when the DAC is ready for it. The actual clocking of the conversion of bytes to audio happen within the DAC using its own (and hopefully sufficiently stable!) clock. There is simply no mechanism for jitter from the computer or the usb cable to affect the output jitter of a modern asynchronous DAC. Any defect in the data stream is because one of the components in the chain (CPU->USB port->cable->USB port->DAC) is operating outside of specification and should be considered broken. All USB cables which meet the USB standard transfer data equally well.

.....

 

Ya. USB audio is packetised and buffered... but that changes with I2C connections and SPDIF (hence why asynchronous DAC's are nice). Is that why people get confused?  

 

Shielded USB cables with secure connectors = good. Those cost like $10. TOSLINK / Coax cables with good SNR and durable connectors = good. Those cost like $20. Double that if you want them to look blingy and shiny. Then again, those previous recommendations are in most cases, for peace-of-mind than anything else. 

 

If you want to sell unobtanium digital cables... then just go out and say that you should buy them because they look cool! I'm totally fine with that- you're being honest.

 

Then there's this %£$@ where we have a $200 ribbon "coaxial" cable that isn't shielded.blink.gif Then again, this is the same place with this gem: 

 

 

Quote:

• DO NOT USE ANY BREAK-IN DEVICES OF ANY KIND ON OUR WIRES!! Doing so will degrade the sound of our cables. Use only music to break in our wires, preferably music with strong transients (i.e. music with lots of percussion and/or plucked instruments).

 

post #1704 of 1790
Quote:
Originally Posted by Happy Camper View Post

The only difference in the setup was the cable. Not even the volume control was adjusted.

Sony i3 using foobar/ASIO output to a Hilo Lynx DAC, balanced out to a Simaudio Moon 340i amp into HE-6. Material was flac from CD and vinyl rips @ 24/96.

I'm not making any claim for science but I'm not taking science doubletalk to tell me I'm either lying (which is often insinuated) or fooled.

The Radio Shack is a $10 two meter cable. Sorry, can't quote the model of the cable but it was a 2.0 USB a to b cable.

I believe the difference in cable geometry and silver clad wire on the signal lines reduces jitter and improved the timing. Whatever the reasoning, I did hear a difference in sound quality for the better.


See how you said: "I believe". That is what you are doing. And you are allowed to do that. I think even most of the salesmen that sell these things also "believe". You see, the thing is that humans often believe things that are just not true. The more people, the more this effect runs rampant. When the people thought the earth was flat and you would say it was round, you would have gotten lynched by the church.

If you take time to learn about how a DAC works, or for that matter even a CD transport, you would see that there is such a thing as a data buffer. This data buffer takes the stream of data and stores it, AFTER it has gone through the USB cable. As such, it is impossible to hear any usb cable sound on that fact alone. Why? Because the jitter and timing "problems" you are "hearing" would happen between the buffer and the dac.

Now, I am not saying you are lying - you DID hear something. But you just placed it in the wrong area. It wasn't in the cable. USB cable sound is, scientifically speaking, close to fuel magnet scams.

Another example: You see, every time I change the oil in my truck, I always feel it's running smoother and more efficiently and I used to buy the best oil I could (read expensive). But, there is a certain weight of oil that is best for the way the engine (oil pump, oil passages, spray nozzles, main crankshaft bearing tolerances. You only need 5w 50 if you actually own a race engine with those tolerances and temps. A normal engine, when cold, will just wear down faster with the thin oil. And 90% of all wear happens at startup.
Edited by ev13wt - 7/12/13 at 2:59am
post #1705 of 1790
Quote:
Originally Posted by bigshot View Post

 

This is the Sound Science forum. We try to understand the reasons why things happen, and we try to verify results. There really isn't much point marching in, claiming something and belligerently refusing to play by the rules of science. There are a bunch of other forums in Head-Fi for that. Knowing why Sound Science exists, why would anyone come in here and do that unless they *wanted* to provoke the inevitable requests for proof?

 

The response isn't monotonous, the incessant trolling is.

 

The " Sound Science " is deaf.


Edited by zorin - 7/12/13 at 3:39am
post #1706 of 1790
Unobtanium digital cables don't improve the sound. They do improve the music (your experience).
 
Remember the saying. "I'm addicted to placebos. I'd give them up, but it wouldn't make any difference."
Quote:
Originally Posted by ev13wt View Post


Now, I am not saying you are lying - you DID hear something. But you just placed it in the wrong area. It wasn't in the cable. USB cable sound is, scientifically speaking, close to fuel magnet scams.

Another example: You see, every time I change the oil in my truck, I always feel it's running smoother and more efficiently and I used to buy the best oil I could (read expensive). But, there is a certain weight of oil that is best for the way the engine (oil pump, oil passages, spray nozzles, main crankshaft bearing tolerances. You only need 5w 50 if you actually own a race engine with those tolerances and temps. A normal engine, when cold, will just wear down faster with the thin oil. And 90% of all wear happens at startup.

 

To elaborate all this..as ev13wt is saying... Placebo is real (and is a major thing complicating medical research, to my frustration, for example.)

 

Perception of music and enjoyment of it is just as much about engineering physics as it is about psychology. 

 

Expensive, shiny unobtanium USB cables may make for better perceived PRaT and Transients and soundstaging and whatever despite it not making an actual objective difference. 

 

...Unless you're scientifically minded and whatnot... being scientifically minded in this case is actually sort of a shame, if you think about it in a certain way. 

post #1707 of 1790
Quote:
Originally Posted by esldude View Post

One file was a 96 khz recording of a Clark Terry song using a friend's Wireworld USB (was either Ultraviolet or Starlight didn't record which).  Then again using a 33 foot monoprice USB extender the end of which was using a generic USB cable that came in an HP printer.   I even changed the scale to match what Wireworld has best I could tell.  They appeared to have it at 25%.  Even if I zoomed in like their second picture it looks like a flat line.  Zoomed in 5 times closer it looks a bit fuzzy.   This isn't a zero.  Doing the FFT on it, there is a peak of -107 db at 60 hz.  Everywhere else is around -115db to 118 db.  That is the basic noise level of the equipment on hand.  Later with quieter equipment got the same result between USB cables just the noise floor was lower by 8-10 decibels.  I didn't have the Wireworld on hand at that later time.

 

Did you use the same USB device for both playback and recording ? Not that I believe in USB cables sounding different, but if the DAC and ADC share the same clock (as it likely is the case if they are in the same device), then the loopback recording will not show all the jitter that is there in the analog output of the DAC. Otherwise, a difference signal of less than -100 dB is difficult to achieve even when both recordings are made under the same conditions (same cables etc.), since the clock frequency does tend to have a small amount of slow random variation (an example can be seen here).


Edited by stv014 - 7/12/13 at 3:15am
post #1708 of 1790
Quote:
Originally Posted by esldude View Post

I asked earlier if Wireworld has an explanation.  I looked and they don't have any that are convincing to me.  They do have a page showing what they say is waveform error for generic USB vs theirs. 

 

http://wireworldcable.com/Image_Library.html  Look at the January 2013 white paper under "product sheets".

 

Here they say they played a music waveform through one cable and then differenced it against their USB cabled.  I am assuming they recorded the result and subtracted one waveform from another.  Just happens I spent some time doing just that with USB, and analog cables a bit over a year ago.  I still have the files.  Here is a screenshot of my result. 

 

For some reason, I find that graph to be absolutely hilarious. (And I'd cry shenanigans if you got anything different.)

 

Then I cried a bit inside. Those uber cables are so shiny and now I won't be able to justify getting them... *sniffle*

 

Edit: sv014 has a rather fascinating point. Not that I think it'd make a difference to our graph, but it is interesting. 


Edited by Chromako - 7/12/13 at 3:22am
post #1709 of 1790

I have quite a few friends who are fitness or bodybuilding enthusiasts. Flip through their bodybuilding magazines or visit some of their web forums and you will find all manner of snakeoil being sold as "supplements". They have a wide variety of supplements that are marketed for a number of purposes using a lot of junk science. These things get really expensive and even though none of them have been scientifically proven to work and all of them make grandiose claims that they can't back up, they still sell this stuff for hundreds of dollars. In fact, it seems there is not only a link between the cost of a supplement and its perceived effectiveness, but there is also a sense of pride that comes with using the best, most expensive supplements.

 

But you have to realize one thing. Despite the fact that they believe all this junk science and push expensive supplements that don't work, a lot of the people who review these supplements and write the articles for those magazines and forums are, without a doubt, HUGE! They may buy into a lot of junk science and waste hundreds (or even thousands) on products that don't work, but a lot of the other things they teach about bodybuilding do work and give great results as can be seen from looking at their bodies. So, do we ignore everything they say because they buy into the junk science behind the supplement industry? No, there's a lot these people do know about. We just happen to know more than they do about supplements; that doesn't change the fact that when it comes to designing an optimal meal plan or workout they may know far more than we do.

 

Our own hobby is the same way. There's a lot of junk science and snake oil in our hobby, especially when it comes to cables and interconnects. But just like we wouldn't claim Mr. Olympia is completely unreliable because he believes in supplements (in fact, the current Mr. Olympia does), we shouldn't throw out the baby with the bathwater when judging reviewers in our field of interest either. They may have been suckered in by the junk science of the interconnect industry, but that doesn't automatically mean they can't be trusted when it comes to their opinion on other equipment.

post #1710 of 1790


So, do we ignore everything they say because they buy into the junk science behind the supplement industry? No, there's a lot these people do know about. We just happen to know more than they do about supplements; that doesn't change the fact that when it comes to designing an optimal meal plan or workout they may know far more than we do.

 

Our own hobby is the same way. There's a lot of junk science and snake oil in our hobby, especially when it comes to cables and interconnects. But just like we wouldn't claim Mr. Olympia is completely unreliable because he believes in supplements (in fact, the current Mr. Olympia does), we shouldn't throw out the baby with the bathwater when judging reviewers in our field of interest either. They may have been suckered in by the junk science of the interconnect industry, but that doesn't automatically mean they can't be trusted when it comes to their opinion on other equipment.

Wise words, indeed, dear Ma'am or Sir.  

 

Just be careful, and use logic (that's what all ye peeps do here in Sound Science, right?)

 

Example: I've, shockingly, gotten some nice information from the notorious 6Moons site... once the magniloquent prose an nonsense gobbledygook is excised (albeit there's depressingly little left after that endeavour.)

 

 beerchug.gif


Edited by Chromako - 7/12/13 at 5:21am
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