JREF Homepage Swift Blog Events Calendar $1 Million Paranormal Challenge The Amaz!ng Meeting Useful Links Support Us
James Randi Educational Foundation JREF Forum
Forum Index Register Members List Events Mark Forums Read Help

Go Back   JREF Forum » JREF Topics » Latest Commentary Issues
Click Here To Donate

Notices


Welcome to the JREF Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.

Reply
Old 1st October 2007, 07:23 AM   #1
Blight
Scholar
 
Blight's Avatar
 
Join Date: Jan 2007
Location: Israel
Posts: 107
Lightbulb [Merged]Magic Cables

It's funny reading this weekend's JREF report.

People are so misguided about audio/video cables. It all stems from the change from analog to digital.

Analog cable required good shielding and sturdy materials, otherwise you'd get noise and possibly lose some frequencies.

Digital cable is a lot simpler. It either works or it doesn't. There is no noise, there is no loss in frequency range (other than lossy digital compression such as Dolby Digital or DTS which have nothing to do with the cable itself). Better cables do exist, but the "better" is not about quality, it's about distance. With digital cable, the better the cable is, the longer the distance the signal can travel without losing integrity.

When digital cable fails, you'll get serious distortion or simply no audio at all. The problem is, people are not aware of this, they still thinking in analog terms and as such, people are cashing in on their misconceptions.
Blight is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 1st October 2007, 10:39 PM   #2
graphicsguy
New Blood
 
Join Date: Oct 2007
Posts: 22
I agree Blight. I worked in electronics plus worked with pro audio equipment regularly (live sound, recording) and the consumer side of things is ridiculous. I used to tell people not to worry about "monster cable" and such, "Just keep the cables as short as possible. Get good quality, but don't break the bank."

I haven't kept up with the technology for years (I simply don't care that much anymore) so I can only imagine how bad it's gotten.
graphicsguy is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 04:12 AM   #3
Cuddles
Decoy
Moderator
 
Cuddles's Avatar
 
Join Date: Jul 2006
Location: A magical land full of pink fluffy sheeps and bunnies
Posts: 16,566
Originally Posted by graphicsguy View Post
I can only imagine how bad it's gotten.
This bad.
__________________
I am not a little teapot.
Cuddles is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 05:24 AM   #4
Freethinker
Graduate Poster
 
Freethinker's Avatar
 
Join Date: Oct 2005
Location: The Uncanny Valley
Posts: 1,358
There is no such thing as "digital" cable when it comes to audio. There are digital fiber-optic or data cables, but speaker cable is speaker cable. All audio signals are analog when they leave the tuner/player etc. regardless of how the audio is stored or transmitted. The concept of digital cables is a marketing scheme for gullible consumers.
__________________
"Did it indeed seem probable, as he had once overheard Dunbar ask, that the answers to the riddles of creation would be supplied by people too ignorant to understand the mechanics of rainfall? Had Almighty God, in all His infinite wisdom, really been afraid that men six thousand years ago would succeed in building a tower to heaven?"

Thoughts of the Chaplain in Heller's Catch-22
Freethinker is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 11:06 AM   #5
NoAstronomer
Student
 
Join Date: Oct 2007
Location: New Jersey
Posts: 39
What I'm laughing at right now is that there are so many people focused on the 'fidelity' of the sound: huge speaker setups, digital cables, CD vs tape and yet what do we find people *really* want: portable music.

So much so that they rip songs at low sampling rates, so they can get as many as possible onto their iPod, and listen to them through crappy earbuds.
NoAstronomer is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 11:12 AM   #6
IMST
If Charlie Parker Was a Gunslinger, There'd Be a Whole Lot of Dead Copycats
 
IMST's Avatar
 
Join Date: Jul 2007
Location: Seattle
Posts: 6,128
Originally Posted by Blight View Post
When digital cable fails, you'll get serious distortion or simply no audio at all. The problem is, people are not aware of this, they still thinking in analog terms and as such, people are cashing in on their misconceptions.
Originally Posted by Freethinker View Post
There is no such thing as "digital" cable when it comes to audio. ...snip... The concept of digital cables is a marketing scheme for gullible consumers.
I have some expertise here. It is entirely possible to get minor distortion with a digital carrying cable as well by letting other digital carrying cables induce current the same way an analog carrying cable would. Proper shielding is still essential. There also is such a thing as a digital cable. The signal is transmitted the same way as an analog signal would be along the cable itself, but digital audio devices expect very specific impediances within the cables to transmit properly with a minimum of digital errors. IIRC, a S/PDIF (consumer level) cable with RCA connectors should be 75 ohm exactly and an AES/EDU (professional level) cable with XLR connectors should be 110 ohm exactly.
IMST is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 02:25 PM   #7
AudioFreak
Critical Thinker
 
AudioFreak's Avatar
 
Join Date: Mar 2007
Location: Gilbert, AZ
Posts: 380
Indeed! I don't know where these people get their crazy ideas. I do LOVE to listen to music on a high quality playback system. Cables are, as everyone else above mentioned, important. But I have to agree with the term "digital cable" being ridiculous. Especially with... er... (remembers forum rules) people like Extreme Skeptic who refuse to accept reason and logic based on facts and would rather perpetuate lies told by the scamming manufacturers that sold them their worthless equipment. I'm an audio engineer and it doesn't take much study in that field to know that there is no way that a S/PDIF or AES/EBU cable would "color" the audio it's transmitting.

Indeed there are cables with specific connectors, pin patterns and resistances that are precisely engineered to carry audio of a certain digital format. Just like I wouldn't use the RCA cable from the CD player in the living room to make a S/PDIF loop, nor would I use just any random coax cable with a BNC connector for word clock. But in the end it's all electricity going down a wire. There is no A/D or D/A conversion happening in the cable itself. And at audio frequencies, skin effect isn't going to be much of an issue. Forget Monster (not to say they don't make good quality cables, but their sales pitch is BS and for that, they lose my business).

If you're absolutely concerned about the quality of the materials used, buy Mogami or Gepco. They're legitimate professional standards and made with extremely high quality materials. For 98% of applications out there, to use them is still ridiculous! If you're putting together a media studio and you have the budget, then yes. But for a home system? NO WAY!

Take that ridiculous amount of money you were about to blow on some Valhalla cables and put up some acoustic treatment in your listening room if you're so concerned! I love how they're worried about their cables and amplifiers to an insane degree but don't seem much concerned about the flutter echo in their listening environment.
__________________
[font="Book Antiqua"]Logic and evidence mean nothing to me because I'm not biased, but apparently you are. - ExtremeSkeptic

Straw Man Complex - Real. Heavy. Rock.

Tarktones Audio - Recording, Mixing and Mastering
AudioFreak is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 03:49 PM   #8
IMST
If Charlie Parker Was a Gunslinger, There'd Be a Whole Lot of Dead Copycats
 
IMST's Avatar
 
Join Date: Jul 2007
Location: Seattle
Posts: 6,128
Originally Posted by AudioFreak View Post
I love how they're worried about their cables and amplifiers to an insane degree but don't seem much concerned about the flutter echo in their listening environment.
A local (shudder) church hired me to help figure out what was wrong with their sound system a while back. People were having trouble understanding the speech. They had a decent system with Mackie everything, functional mics, and not too horrifying gain structure, so there was no obvious problem. So I stepped into the middle of the room and clapped once. 4 seconds later the flutter echo finally died down.

I could not convince them that that was the issue.
IMST is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 05:46 PM   #9
AudioFreak
Critical Thinker
 
AudioFreak's Avatar
 
Join Date: Mar 2007
Location: Gilbert, AZ
Posts: 380
Originally Posted by In My Spare Time View Post
I stepped into the middle of the room and clapped once. 4 seconds later the flutter echo finally died down.

I could not convince them that that was the issue.
HOLY COW!!!!!!! Jeez! Why didn't they just pray to Jesus to fix it? Sorry... getting off topic.

But it's a great example of how people can have such horrific mis-conceptions about this stuff. They are convinced there is a magic box for every issue. And for everyone with that belief there is some sort of shady merchant willing to sell them something with fantastic psycho-somatic results. It's really sad.
__________________
[font="Book Antiqua"]Logic and evidence mean nothing to me because I'm not biased, but apparently you are. - ExtremeSkeptic

Straw Man Complex - Real. Heavy. Rock.

Tarktones Audio - Recording, Mixing and Mastering
AudioFreak is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 05:59 PM   #10
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Quote:
Digital cable is a lot simpler. It either works or it doesn't. There is no noise, there is no loss in frequency range (other than lossy digital compression such as Dolby Digital or DTS which have nothing to do with the cable itself). Better cables do exist, but the "better" is not about quality, it's about distance. With digital cable, the better the cable is, the longer the distance the signal can travel without losing integrity.
Technically speaking you can distort a digital signal. I forget the math though or haven't learned how it works yet though because apparently a square wave is composed of multiple harmonics.. In fact the very first problems involving distortion was not an analog system but digital.

Last edited by technoextreme; 2nd October 2007 at 06:08 PM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 06:51 PM   #11
AudioFreak
Critical Thinker
 
AudioFreak's Avatar
 
Join Date: Mar 2007
Location: Gilbert, AZ
Posts: 380
Originally Posted by technoextreme View Post
Technically speaking you can distort a digital signal. I forget the math though or haven't learned how it works yet though because apparently a square wave is composed of multiple harmonics.. In fact the very first problems involving distortion was not an analog system but digital.
mmmm.... no, actually. Distortion existed and was a problem before digital audio was even conceived. That's the problem with analog; trying to get the best sound by finding the middle ground between the noise floor and undesirable distortion from going too hot.

And yes, you can theoretically distort the digital signal but the level of the square wave pulses has absolutely no bearing on the quality of the audio. Think of AM vs FM radio. It doesn't matter how hard that FM signal is blasted and distorted because the FM signal is not the audio itself. It is the changes in that signal in which the audio is encoded.

The only distortion you can really end up with is jitter, but that's got little other than resistance to do with the cable. If you're serious about it, you've got word clock going separately and you have everything structured properly with master/slave or loop settings in place.

Long story short, the square waves are a modulated carrier of the audio information. The only distortion to them that has any bearing is if the receiving device can't tell the difference between 0 and 1 which might occur with a hardware failure or if you've got a bad opamp and a wicked case of DC offset. Sorry but this sort of scenario just doesn't happen in any real world situation.
__________________
[font="Book Antiqua"]Logic and evidence mean nothing to me because I'm not biased, but apparently you are. - ExtremeSkeptic

Straw Man Complex - Real. Heavy. Rock.

Tarktones Audio - Recording, Mixing and Mastering
AudioFreak is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 07:13 PM   #12
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Quote:
mmmm.... no, actually. Distortion existed and was a problem before digital audio was even conceived. That's the problem with analog; trying to get the best sound by finding the middle ground between the noise floor and undesirable distortion from going too hot.
Mmmm... Yes. I know what I was talking about. The very first problems with distortion involved a digital signal. It wasn't analog. Hell I don't think there was any analog systems at all back during the turn the century
Quote:
And yes, you can theoretically distort the digital signal but the level of the square wave pulses has absolutely no bearing on the quality of the audio. Think of AM vs FM radio. It doesn't matter how hard that FM signal is blasted and distorted because the FM signal is not the audio itself. It is the changes in that signal in which the audio is encoded.
Perhaps I'm thinking of the wrong phenomenon. I do know a square wave is composed of infinite harmonics. I don't know what the effect would be of distorting a few of those harmonics.

Last edited by technoextreme; 2nd October 2007 at 07:17 PM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 07:20 PM   #13
AudioFreak
Critical Thinker
 
AudioFreak's Avatar
 
Join Date: Mar 2007
Location: Gilbert, AZ
Posts: 380
Originally Posted by technoextreme View Post
Mmmm... Yes. I know what I was talking about. The very first problems with distortion involved a digital signal. It wasn't analog. Hell I don't think there was any analog systems at all back during the turn the century
Whew, good to know you're just messing with us here. For a minute there, I thought you were serious. Only someone with no brain power at all would actually believe that. Cute, really.

Originally Posted by technoextreme View Post
Perhaps I'm thinking of the wrong phenomenon. I do know a square wave is composed of infinite harmonics. I don't know what the effect would be of distorting a few of those harmonics.
It would have no affect on the encoded audio at all. And there certainly aren't an infinite number of harmonics to a square wave and even if there were it's got nothing to do with magical cables that mysteriously make your audio sound better.
__________________
[font="Book Antiqua"]Logic and evidence mean nothing to me because I'm not biased, but apparently you are. - ExtremeSkeptic

Straw Man Complex - Real. Heavy. Rock.

Tarktones Audio - Recording, Mixing and Mastering

Last edited by AudioFreak; 2nd October 2007 at 07:26 PM.
AudioFreak is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 07:55 PM   #14
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Quote:
And there certainly aren't an infinite number of harmonics to a square wave and even if there were it's got nothing to do with magical cables that mysteriously make your audio sound better.
For the first question. Yes. The mathematical definition to a square wave is just a bunch of sine waves added together. For this reason Im suspect of the fact that you need to actually use a transmission line(AKA vodo audio cables). It's kind of idiotic though to call them digital cables when they are the same thing as audio cables. In fact the very first problems with distortion was with the telegraph and all that was a simple on and off.

Last edited by technoextreme; 2nd October 2007 at 08:10 PM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 08:11 PM   #15
AudioFreak
Critical Thinker
 
AudioFreak's Avatar
 
Join Date: Mar 2007
Location: Gilbert, AZ
Posts: 380
Originally Posted by technoextreme View Post
For the first question. Yes. The mathematical definition to a square wave is just a bunch of sine waves added together. For this reason Im suspect of the fact that you need to actually use a transmission line(AKA vodo audio cables).
Uhm, nope again.



Where in the world do you come up with these absurd definitions? Care to cite your source on your claim that distortion comes from digital audio or that a square wave is "a bunch of sine waves added together"? And what would that have anything to do with needing a "transmission line"? You're talking absolute nonsense.

Quit subscribing to voodoo. I'll no longer entertain this lunacy lest you supply some kind of genuine argument based on something other than woo.

Back on topic; cables have 1 job and 1 job alone. To get a signal from point A to point B intact. Not to color or enhance the sound. To use an analogy, the lines on the pavement don't have any effect on the fuel efficiency of your vehicle or make your headlights brighter, nor does it make your destination any more or less exciting.

With the exception of replacing a bad cable, there should be no difference detected using one cable over another. Manufacturer quality standards will determine how much abuse the cable will take before it gives out. THAT should be the price-determining factor. Not claims of magic.
__________________
[font="Book Antiqua"]Logic and evidence mean nothing to me because I'm not biased, but apparently you are. - ExtremeSkeptic

Straw Man Complex - Real. Heavy. Rock.

Tarktones Audio - Recording, Mixing and Mastering
AudioFreak is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 2nd October 2007, 08:16 PM   #16
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Quote:
Where in the world do you come up with these absurd definitions? Care to cite your source on your claim that distortion comes from digital audio or that a square wave is "a bunch of sine waves added together"? And what would that have anything to do with needing a "transmission line"? You're talking absolute nonsense.
You really are pathetic. You just posted an equation with a bunch of sine waves added together composed of different frequencies.
Quote:
And what would that have anything to do with needing a "transmission line"?
Any type of frequency component means you may need a transmission line. It depends on the frequency and the length of the line though. Also the transmission line theory comes from the telegraph and problems people had from that. Without transmission line theory we wouldn't have had a telegraph because of the distortion just from the dashes and dots.
Quote:
Quit subscribing to voodoo. I'll no longer entertain this lunacy lest you supply some kind of genuine argument based on something other than woo.
It's not woo it's science.

Last edited by technoextreme; 2nd October 2007 at 08:32 PM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 4th October 2007, 02:07 AM   #17
WDB
Student
 
Join Date: Aug 2007
Location: London
Posts: 41
I agree a square wave ( or any other shape wave ) can be represented as a sum of sine waves but why is this relevant ? Whatever sort of distortion occurs occurs on the square wave so long as it is not so catastrophic that you can still differentiate the 1s from the 0s, how is this going to affect sound quality ?
WDB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 4th October 2007, 02:18 AM   #18
JoeEllison
Cuddly Like a Koala Bear
 
JoeEllison's Avatar
 
Join Date: Jul 2007
Location: Florida
Posts: 7,276
Those people are a bunch of loonies. How much for Valhalla cables? Really?

Ultimately, I think it all boils down to people with lots of money to burn, being cheated by people who know what buttons to push. Once you find some moron willing to spend $100,000 on a stereo system, you can get him to blow another $10,000 on nothing much, that promises to make his already-overpriced system not actually sound any better.
JoeEllison is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 4th October 2007, 01:26 PM   #19
dudalb
Penultimate Amazing
 
dudalb's Avatar
 
Join Date: Aug 2007
Posts: 22,782
I am waiting for the arrival of ExtremeSkeptic to this thread.
dudalb is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 4th October 2007, 04:20 PM   #20
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Quote:
I agree a square wave ( or any other shape wave ) can be represented as a sum of sine waves but why is this relevant ? Whatever sort of distortion occurs occurs on the square wave so long as it is not so catastrophic that you can still differentiate the 1s from the 0s, how is this going to affect sound quality ?
You know what I'll just do the math. As much as it is a pain in the butt it should be a very simple problem. Im really not even saying there is a problem I just want to know what the mathematical reprsentation of the wave should be.

Last edited by technoextreme; 4th October 2007 at 04:35 PM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 4th October 2007, 11:11 PM   #21
AudioFreak
Critical Thinker
 
AudioFreak's Avatar
 
Join Date: Mar 2007
Location: Gilbert, AZ
Posts: 380
My point was that the definition of "a bunch of sine waves" wasn't exactly an accurate description. Regardless, the composition of a square wave has nothing to do with magical cables.

Why is there not one legitimate professional studio or academic institution that shares the same ideas as those alleged by people who stand to gain enormous profit from the buying of said woo? How come nobody except the people who are selling it, the people bribed to promote it and the poor saps that buy it (who are never professionals in the field with any academic background on the topic) is willing to vouch for the legitimacy of these claims?

There's no research to back it up. Zilch.
__________________
[font="Book Antiqua"]Logic and evidence mean nothing to me because I'm not biased, but apparently you are. - ExtremeSkeptic

Straw Man Complex - Real. Heavy. Rock.

Tarktones Audio - Recording, Mixing and Mastering
AudioFreak is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 4th October 2007, 11:18 PM   #22
pipelineaudio
Illuminator
 
pipelineaudio's Avatar
 
Join Date: Feb 2006
Location: Wickenburg, AZ
Posts: 3,669
There are TONS of audio professionals who should know better who buy into this nonsense.

Here's one thing I deal with, seemingly every 15 minutes or so, the malarchy that some DAW's summ magically better than others

http://forums.randi.org/showthread.php?t=94903

No matter how many times tests like these are done, people still belive this rubbish

Want to see a worse one? http://recforums.prosoundweb.com/ind...sg/9441/0/0/0/

SEVENTEEN PAGES of the world's finest audio engineers buying into a magic 1500$ IEC AC cable
__________________
Can someone give me a better name for SLAG FAIRY?
pipelineaudio is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 01:11 AM   #23
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Location: Whithin earshot of the North Sea
Posts: 16,600
On the composition of square-waves:

A square-wave (an ideal one) is composed of the base frequency and all the odd harmonics. In any real-life waveform, of course, the harmonics will be attenuated to some degree. The less harmonics are present, the more sinus-like does it become.

However, those harmonics should have no influence on the information content in a digital transmission system. A cable will attenuate higher harmonics more than the lower ones, but that is not the reason for using impedance matching.

The reason you may want to use impedance matching (and thus transmission line technology) is to avoid reflections. Reflections come when there is a mismatch in a transmission line because an impedance mismatch means that not all the energy is transferred across the mismatch. The surplus energy is reflected back towards the source, and will result in distortion of the waveform. If such a distortion is severe enough to cause a sampling error (or a reclocking error), it will change the transmitted information.

However, for a mismatch to have such an effect, it must have a physical extent that is a considerable fraction of the wavelength of the carrier. And as digital audio carriers are in the hundred kHz range, the wavelenghts are are in the mile range, so impedance matching has at most a very marginal importance. Especially if we talk equipment interconnects.

All of which means that cables are rather uncritical (that is one of the reasons for using digital in the first place). Of course, they should be screened, if only to keep noise from coming out of them. (twisted pairs will also do)

Hans
__________________
Don't. Just don't.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 01:17 AM   #24
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Location: Whithin earshot of the North Sea
Posts: 16,600
Originally Posted by pipelineaudio View Post
There are TONS of audio professionals who should know better who buy into this nonsense.

*snip*
SEVENTEEN PAGES of the world's finest audio engineers buying into a magic 1500$ IEC AC cable
Uhh, what exactly qualifies them as the world's finest audio engineers? And what are the qualifications required of an audio engineer, in the first place?

All that said, a professional audio engineer is likely to make a living selling (selling in the broad sense, he might be constructing it) audio equipment, so he may not be the most unbiased source you can get.

Hans
__________________
Don't. Just don't.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 02:34 AM   #25
pipelineaudio
Illuminator
 
pipelineaudio's Avatar
 
Join Date: Feb 2006
Location: Wickenburg, AZ
Posts: 3,669
Originally Posted by MRC_Hans View Post
Uhh, what exactly qualifies them as the world's finest audio engineers? And what are the qualifications required of an audio engineer, in the first place?

All that said, a professional audio engineer is likely to make a living selling (selling in the broad sense, he might be constructing it) audio equipment, so he may not be the most unbiased source you can get.

Hans
I should have said "recording engineers"

Yeah "audio engineers" kind of leaves the door wide open lol
__________________
Can someone give me a better name for SLAG FAIRY?
pipelineaudio is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 09:29 AM   #26
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Originally Posted by MRC_Hans View Post

However, for a mismatch to have such an effect, it must have a physical extent that is a considerable fraction of the wavelength of the carrier. And as digital audio carriers are in the hundred kHz range, the wavelenghts are are in the mile range, so impedance matching has at most a very marginal importance. Especially if we talk equipment interconnects.
I knew that. The problem is that the square wave is composed of multiple harmonics. Do you care about the frequency components of the individual sine waves or the frequency component of the square wave?
Quote:
There's no research to back it up. Zilch.
Yeah there is. The first problem that transmission lines solved was the distortion of a square wave. I know it's possible I just have no clue how to solve the problem because of the above question. If it is just the frequency of a square wave then yes it doesn't matter and the problem is a matter of distance. If the sine wave components of the square matters then I have no clue what actually happens because your bouncing back parts of the square wave. Then you would have to do the math.

Last edited by technoextreme; 5th October 2007 at 09:36 AM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 10:25 AM   #27
WDB
Student
 
Join Date: Aug 2007
Location: London
Posts: 41
Originally Posted by technoextreme View Post
I knew that. The problem is that the square wave is composed of multiple harmonics. Do you care about the frequency components of the individual sine waves or the frequency component of the square wave?
You don't much care about the frequency components much higher than the frequency of the square wave, as the frequency of the components increase their amplitude and importance decrease. You could completely loose all the frequencies above say 2x the frequency of the square wave and what you'd be left with would still be a near enough approximation of the square wave to still extract all the binary data with zero error.

Last edited by WDB; 5th October 2007 at 10:27 AM. Reason: spelling!
WDB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 03:16 PM   #28
tot
New Blood
 
Join Date: Oct 2007
Location: France
Posts: 11
Originally Posted by Blight View Post
When digital cable fails, you'll get serious distortion or simply no audio at all. The problem is, people are not aware of this, they still thinking in analog terms and as such, people are cashing in on their misconceptions.
In the S/PDIF standard in addition to the bits the signal also carries the timing information to the DAC. The timing always have errors called jitter, which is caused mainly by the source clock, the cable and the receiving circuit of the DAC.

The cable distortion causes jitter because the edges of the bits where the clock is recovered are not exact. With optical cables even vibrations add to distortion and thus jitter.

The DAC should be immune to the incoming jitter by "averaging" the recovered clock. Unfortunately many consumer level DACs have not been very good at that, but they have improved a lot over the years.

The point is that even in S/PDIF the cable can change the sound even if all the bits are sent without errors. But if the cable causes audible jitter the solution is to get a proper DAC, not an expensive cable.

Teemu
tot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 04:36 PM   #29
Monza
Muse
 
Monza's Avatar
 
Join Date: Jan 2005
Posts: 929
I just think it would be fun to go to a bank and try to get a loan. I wonder what the loan officer would say when you state you want to buy $40,000 stereo cables?
Monza is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 5th October 2007, 04:37 PM   #30
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Originally Posted by WDB View Post
You don't much care about the frequency components much higher than the frequency of the square wave, as the frequency of the components increase their amplitude and importance decrease. You could completely loose all the frequencies above say 2x the frequency of the square wave and what you'd be left with would still be a near enough approximation of the square wave to still extract all the binary data with zero error.
Thanks. That makes sense. Without the math it just kind of confusing because I know the Fourier series is a square wave but Im fairly certain you don't even start with a square wavve to begin with.

Last edited by technoextreme; 5th October 2007 at 04:47 PM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 6th October 2007, 01:02 AM   #31
ktesibios
Worthless Aging Hippie
 
ktesibios's Avatar
 
Join Date: Feb 2002
Location: Los Angeles
Posts: 1,493
Originally Posted by MRC_Hans View Post
Uhh, what exactly qualifies them as the world's finest audio engineers? And what are the qualifications required of an audio engineer, in the first place?
Hans
Originally Posted by pipelineaudio View Post
I should have said "recording engineers"

Yeah "audio engineers" kind of leaves the door wide open lol
Exactly right. The qualification is that they have been paid to cut and/or mix records.

I've been working in the industry for nigh on twenty years now and I can tell you from personal observation that the vast majority of recording engineers- and I'm referring to guys who have more gold and platinum records than wall space to hang them on- have no technical education or any clue whatsoever about what is happening 1/8" below the console surface. This is why I am still gainfully employed- because I do have that clue.

An anecdote- some time ago an engineer client and I were talking about a very expensive and kind of hard to use compressor which has, among other things, a knob labeled "crest factor". I commented that it might not be a good idea to put control legends on a piece of studio gear that required a degree in electrical engineering to understand. He retorted "I have a degree in electrical engineering and I don't understand it!"

It's true. He earned a BSEE before getting into the music industry. But after years and years of making records instead of practicing a socially useful profession he's forgotten an awful lot.

Most knob-twisters don't even have that headstart.
__________________
Ship me somewheres east of Suez, where the best is like the worst, where there ain't no ten commandments and a man can raise a small, bristly mustache.
ktesibios is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 8th October 2007, 04:06 AM   #32
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Location: Whithin earshot of the North Sea
Posts: 16,600
Originally Posted by technoextreme View Post
I knew that. The problem is that the square wave is composed of multiple harmonics. Do you care about the frequency components of the individual sine waves or the frequency component of the square wave?
I don't really care at all. It is a very inadequate decoding circuitry that is dependent on the harmonics.

But just to be precise, an individual sine wave does not have any frequency components.

Quote:
Yeah there is. The first problem that transmission lines solved was the distortion of a square wave. I know it's possible I just have no clue how to solve the problem because of the above question. If it is just the frequency of a square wave then yes it doesn't matter and the problem is a matter of distance. If the sine wave components of the square matters then I have no clue what actually happens because your bouncing back parts of the square wave. Then you would have to do the math.
Transmission lines do solve the problem of distortion of the square wave. If it is seriously enough distorted, it is a problem. However, as I told you, an audio interconnect is so short compared to the wavelenght of the digital carrier that even a serious mismatch is not going to cause any problems. The old telegraph lines were long enough; they were cross-continent lines.

As long as the time for bouncing back and forth is of shorter duration than your risetime, they don't matter.

Hans
__________________
Don't. Just don't.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 8th October 2007, 07:24 PM   #33
pipelineaudio
Illuminator
 
pipelineaudio's Avatar
 
Join Date: Feb 2006
Location: Wickenburg, AZ
Posts: 3,669
Originally Posted by ktesibios View Post
Exactly right. The qualification is that they have been paid to cut and/or mix records.

I've been working in the industry for nigh on twenty years now and I can tell you from personal observation that the vast majority of recording engineers- and I'm referring to guys who have more gold and platinum records than wall space to hang them on- have no technical education or any clue whatsoever about what is happening 1/8" below the console surface. This is why I am still gainfully employed- because I do have that clue.
Depends on the situation a lot too. At my shop, and I bet George Massenburg's, "recording engineer" means if you need a tool, last minute, you better be able to make it. We have no use for a Conservatory grad who can't use a soldering iron ten times better than he can use a pencil

But yeah, there are a lot of shmoes out there, and more every day

My personal crusade is the DAW summing myth (and the tiny parts of it that are sort of true) http://forums.randi.org/showthread.php?t=94903
__________________
Can someone give me a better name for SLAG FAIRY?
pipelineaudio is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 8th October 2007, 07:25 PM   #34
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Quote:

An anecdote- some time ago an engineer client and I were talking about a very expensive and kind of hard to use compressor which has, among other things, a knob labeled "crest factor". I commented that it might not be a good idea to put control legends on a piece of studio gear that required a degree in electrical engineering to understand. He retorted "I have a degree in electrical engineering and I don't understand it!"
The same thing happened where I work. The only difference was the fact that it was a temperature knob. People assumed that they could change the temperature settings even though the engineers knew it would damage the parts.
Quote:
However, as I told you, an audio interconnect is so short compared to the wavelenght of the digital carrier that even a serious mismatch is not going to cause any problems.
Yeah. I knew that. I knew that three weeks ago. How does that work for a square wave? The only I know involves the wavelength. What is the wavelength of a square wave?

Last edited by technoextreme; 8th October 2007 at 07:31 PM.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 9th October 2007, 02:32 AM   #35
AudioFreak
Critical Thinker
 
AudioFreak's Avatar
 
Join Date: Mar 2007
Location: Gilbert, AZ
Posts: 380
Originally Posted by technoextreme View Post
Yeah there is. The first problem that transmission lines solved was the distortion of a square wave. I know it's possible I just have no clue how to solve the problem because of the above question. If it is just the frequency of a square wave then yes it doesn't matter and the problem is a matter of distance. If the sine wave components of the square matters then I have no clue what actually happens because your bouncing back parts of the square wave. Then you would have to do the math.
Again, we're talking about magical cables. There's no math involved in "does this sound better because it's traveling down THIS piece of copper instead of this other piece of copper?" Do math all you like but if there's no audible effect, and there never would be since the frequency content of the signal has no bearing on the audio encoded in the binary data, then it's just a waste of money. Simple as that.

Originally Posted by pipelineaudio View Post
Depends on the situation a lot too. At my shop, and I bet George Massenburg's, "recording engineer" means if you need a tool, last minute, you better be able to make it. We have no use for a Conservatory grad who can't use a soldering iron ten times better than he can use a pencil
*looks at Conservatory certificate on wall* Say what you will about schools like the Conservatory; I'm proud of having gone there, applied myself and learned a lot. I think the bad rep comes from the guys who go there thinking that they'll get out of school and all of a sudden get clients who want to pay them $50/hr to mix their stuff on an SSL after a week of grunt work as an intern, and then get angry that they haven't been given "a shot," quit and end up never working in the field. Some people hear that I went to the Conservatory and think that I've got this bad attitude because since I spent money on a school that I feel I should get a red carpet into the A room, which isn't true at all.

And while I'm sure the standards are high when you work for the man who invented the sweepable parametric EQ, I hardly think that being a genius with a soldering iron is a prerequisite for being a good engineer. I've soldered cables, patchbays, made some condenser mics and phantom power supplies as well, but wouldn't say I'm great with a soldering iron. I'm just following schematics. When it comes time to track or mix, I'm not Al Schmidt but I'm not terrible either. Give it a few years.

Sorry, but I take offense to comments like that the way someone who didn't go to a recording school would take offense to being called "uneducated." Bottom line is that it has little to do with a person's abilities or determination, but it's a quick way to gain a good understanding of things. Alright, I've said my peace. Sorry for the derail.
__________________
[font="Book Antiqua"]Logic and evidence mean nothing to me because I'm not biased, but apparently you are. - ExtremeSkeptic

Straw Man Complex - Real. Heavy. Rock.

Tarktones Audio - Recording, Mixing and Mastering
AudioFreak is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 9th October 2007, 05:43 AM   #36
technoextreme
Illuminator
 
technoextreme's Avatar
 
Join Date: Jun 2007
Posts: 3,786
Quote:
Again, we're talking about magical cables. There's no math involved in "does this sound better because it's traveling down THIS piece of copper instead of this other piece of copper?" Do math all you like but if there's no audible effect, and there never would be since the frequency content of the signal has no bearing on the audio encoded in the binary data, then it's just a waste of money. Simple as that.
I wasn't talking to you. This discussion has no relevance to what you are saying and I get the idea that you have no idea what you are talking about. Given sufficient length you need those magical cables which is caused by both the frequency component and the length. It's a rather simple problem involving the length and wavelength. I have no clue what the wavelength of a square wave is.
technoextreme is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 9th October 2007, 10:06 AM   #37
Dan O.
Philosopher
 
Dan O.'s Avatar
 
Join Date: Feb 2007
Posts: 8,716
Originally Posted by technoextreme View Post
I have no clue what the wavelength of a square wave is.
You could get a decent approximation by multiplying the speed of lightWP by the period of the waveformWP and multiplying that by the velocity factorWP for the cable.
Dan O. is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 9th October 2007, 02:29 PM   #38
pipelineaudio
Illuminator
 
pipelineaudio's Avatar
 
Join Date: Feb 2006
Location: Wickenburg, AZ
Posts: 3,669
Originally Posted by AudioFreak View Post
*looks at Conservatory certificate on wall* Say what you will about schools like the Conservatory; I'm proud of having gone there, applied myself and learned a lot. I think the bad rep comes from the guys who go there thinking that they'll get out of school and all of a sudden get clients who want to pay them $50/hr to mix their stuff on an SSL after a week of grunt work as an intern, and then get angry that they haven't been given "a shot," quit and end up never working in the field. Some people hear that I went to the Conservatory and think that I've got this bad attitude because since I spent money on a school that I feel I should get a red carpet into the A room, which isn't true at all.
Well, you hit the nail on the head. YOU may be one of the good ones, and there have been a few we've got over the years, but the majority DO have the attitude you described. You know, as well as I do, that in the past ten years, the class makeup has changed to very rich kids who's parents are letting them try something for a little while with the plan that if it doesnt work out theyre going to law or medical school

Quote:
I've soldered cables, patchbays, made some condenser mics and phantom power supplies as well, but wouldn't say I'm great with a soldering iron. I'm just following schematics.
Again then, you are WAY ahead of your classmates. I think you are selling yourself short. If you are not all that busy at the moment, please PM me. There's a LOT to be done
__________________
Can someone give me a better name for SLAG FAIRY?
pipelineaudio is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 9th October 2007, 03:32 PM   #39
WDB
Student
 
Join Date: Aug 2007
Location: London
Posts: 41
Originally Posted by technoextreme View Post
I wasn't talking to you. This discussion has no relevance to what you are saying and I get the idea that you have no idea what you are talking about. Given sufficient length you need those magical cables which is caused by both the frequency component and the length. It's a rather simple problem involving the length and wavelength. I have no clue what the wavelength of a square wave is.
Do you acknowledge the point that it is not the square wave you are listening to, it doesn't matter if it is not reproduced perfectly all you are doing is extracting binary data. It's not much different from saying that an expensive USB cable will make your ipod sound better.
WDB is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 10th October 2007, 03:32 AM   #40
MRC_Hans
Penultimate Amazing
 
MRC_Hans's Avatar
 
Join Date: Aug 2002
Location: Whithin earshot of the North Sea
Posts: 16,600
Originally Posted by technoextreme View Post
I wasn't talking to you. This discussion has no relevance to what you are saying and I get the idea that you have no idea what you are talking about. Given sufficient length you need those magical cables which is caused by both the frequency component and the length. It's a rather simple problem involving the length and wavelength. I have no clue what the wavelength of a square wave is.
My emphasis.

If you don't have a clue what the wavelenght of a square wave is, I suggest you stay out of thechnical discussions.

Hans
__________________
Don't. Just don't.
MRC_Hans is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

JREF Forum » JREF Topics » Latest Commentary Issues

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 08:22 PM.
Powered by vBulletin. Copyright ©2000 - 2013, Jelsoft Enterprises Ltd.
© 2001-2012, James Randi Educational Foundation. All Rights Reserved.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.