[Magick Man]

Measurable differences?  I also did not say that.

DBT's?  You gonna hang your hat on dbt's for interconnects?   REALLY?

Man, have I got a bridge to sell you.

ps..You have a very very long wait for proper PEER reviewed tests to be presented.  It first requires adherence to basic statistical precepts.....make sure your test regimen is without confounders such that the results of the analysis can be applied to the general population..  I have hilited the relevant "buzz words" as it were...

jnjn

Yes, I readily "hang my hat" on them, as DBTs are the scientific standard and I'll trust them before anyone's sighted tests. FYI, Double Blinding is used to greatly reduce confounding variables and pier review aids to eliminate procedural anomalies. You're not the first around here to make such comments about them, and you won't be the last.

Without proper testing, you might as well use cable elevators, magic crystals, and fairy dust too. They'll do you about as much good.

 

[jnjn]

Quote:

Yes, I readily "hang my hat" on them, as DBTs are the scientific standard and I'll trust them before anyone's sighted tests. FYI, Double Blinding is used to greatly reduce confounding variables and pier review aids to eliminate procedural anomalies. You're not the first around here to make such comments about them, and you won't be the last.
Without proper testing, you might as well use cable elevators, magic crystals, and fairy dust too. They'll do you about as much good.

You clearly do not know me.  You've a learning curve ahead, and it may be rather steep.  Ask questions if you do not understand, as you've been shooting first, yet asking no questions.
 
A scientific standard is one that is invariant of the conditions.
 
A DBT using interconnects requires the changing of the wires via some method.  If one uses simple swaps, then one is subject to the resistance of the contact connections and the loop area of the wires..NEITHER are controlled. 
 
Two interconnects between two chassis form a ground loop which allows the currents to take the path of lowest impedance.  There is NO control, period.
 
And both loop area and contact resistance are significant in terms of the current path that the source's signal will take getting back.  And that's only for class 2 devices.  It gets worse with safety bonded units.  Going differential removes a very significant amount, but even there inductive coupling is ignored.
 
Now, consider the use of an ABX box.  How does that control the path of the return current?
 
Quite honestly, everything I've seen to date has been done with virtually NO control over current path.
 
Is it any wonder audio is lacking rigor?
 
Now are you ready to discuss details of EMC problems with unbalanced equipment, Faraday's law of induction, Amperes, Lenz's law, and electromagnetic compatibility.  Or are you just coining blurbs you've gleaned from forums and wannabe "experts".
 
ps..do you really believe that poorly designed "tests" which confirm preconceived notions is a "scientific standard"?  Your "bar" is far lower than mine.
 
pps.  oh, forgot to add..I already know and understand most of the "approximations" that have been taught, well past the phd level, in the e/m subject I am discussing here.  It is very important to understand where the approximations are useful, where they fall apart.  Please ask questions instead of shooting yourself in the foot.
 
cheers, jnjn

 

[drez]

Quote:

Yes, I readily "hang my hat" on them, as DBTs are the scientific standard and I'll trust them before anyone's sighted tests. FYI, Double Blinding is used to greatly reduce confounding variables and pier review aids to eliminate procedural anomalies. You're not the first around here to make such comments about them, and you won't be the last.
Without proper testing, you might as well use cable elevators, magic crystals, and fairy dust too. They'll do you about as much good.

 
So good engineering should hang on being verified by DBT?  Do you really thin that is reasonable or even beneficial to the progress of audio technology?  I don't think anyone is saying DBT's are a bad thing - just at the moment most of them seem to be backyard setups which are not up to academic research standards (most of them are nowhere near.)  If you really don't trust your sighted hearing or that of other people, then DBT's can be a useful way to provide practical objective data, but other people are quite happy to live with uncertainty of sighted listening compensated by measurements from electronic instruments, and use their on reasoning ability to fill in the gaps.  That's fine either way - to each their own, just be sure to keep in mind the quality of the double blind testing  being done when insisting on the veracity of the data.

 

[Magick Man]

So good engineering should hang on being verified by DBT?  Do you really thin that is reasonable or even beneficial to the progress of audio technology?

If they're properly conducted and verified, yes I do.

 

[bigshot]

I don't think the problem is expectation bias. I think the problem is ego. You could do a million perfectly handled scientific tests and it wouldn't please some people, because they have so much invested in their anecdotal, purely subjective opinion that they can't stand being wrong.

I've seen a pattern. The people who cling to the fairy tales the hardest and get the maddest if someone points out their errors are the folks for whom audiophilia isn't a way to listen to music, but rather a vehicle for self pride. No amount of money is too much, because they aren't spending money on electronics and wires- they're spending it on building themselves up. What they really want is for everyone t be impressed by their accomplishment.

 

[jnjn]

Quote:

Too bad your PhD program didn't include lessons in polite discourse, though it does appear that you did very well in Egotism 101.
Despite the filibuster, proof that there is an audible difference in cables has not been found. Not surprising, after 25 years in this hobby I've not seen or heard any yet.

Polite discourse?  All along you've been treating me in a not so pleasant fashion.   You and many others tend to classify individuals in one of two categories, those that agree with you, and those that have their heads screwed on backwards.
 
Go back and review your posts.
 
Now, the salient point.  Do you really think that unscientifically uncontrolled, idiotic tests repeated a thousand times, is proof that there is not an audible difference??  And when I explain the physics behind why those tests are uncontrolled, you bolt from a technical discussion.
 
Discuss technical issues if you can.  I note you did not, but rather you attack the individual.
 
I've got news for you.  I'm not your enemy.  Your incomplete understanding of the scientific method, you lack of understanding of where all the audio testing fails that method, and your inability to realize that.... is.
 
jnjn

 

[jnjn]

Quote:

I don't think the problem is expectation bias. I think the problem is ego. You could do a million perfectly handled scientific tests and it wouldn't please some people, because they have so much invested in their anecdotal, purely subjective opinion that they can't stand being wrong.
I've seen a pattern. The people who cling to the fairy tales the hardest and get the maddest if someone points out their errors are the folks for whom audiophilia isn't a way to listen to music, but rather a vehicle for self pride. No amount of money is too much, because they aren't spending money on electronics and wires- they're spending it on building themselves up. What they really want is for everyone t be impressed by their accomplishment.

Unfortunately, I see that on both sides of the argument.    I must admit however, that in my experience, a higher percentage of the subjective people are more willing to listen to why they may be in error when faced with a well constructed scientifically based argument, whereas I see far too many objective people cling desperately to their unsupported or inaccurate understandings, and resort instead to personal attacks like the ego card just exercised.
 
cheers, jnjn

 

[liamstrain]

Quote:

in my experience, a higher percentage of the subjective people are more willing to listen to why they may be in error when faced with a well constructed scientifically based argument, whereas I see far too many objective people cling desperately to their unsupported or inaccurate understandings, and resort instead to personal attacks like the ego card just exercised.
 

 
Oddly - that is the exact opposite of my experience. 
 
Regardless - though I do not understand it fully, I thank you for your expertise and efforts to bring us better knowledge about the science surrounding these topics. I too am skeptical of the audibility, but always willing to learn. 

 

[xnor]

Quote:

Originally Posted by jnjn /img/forum/go_quote.gif
 
Now, the salient point.  Do you really think that unscientifically uncontrolled, idiotic tests repeated a thousand times, is proof that there is not an audible difference??  And when I explain the physics behind why those tests are uncontrolled, you bolt from a technical discussion.

Feel free to provide more scientifically, more controlled, less idiotic tests that show audible differences. Good luck.
 
Quote:

 
Oddly - that is the exact opposite of my experience. 
 
Regardless - though I do not understand it fully, I thank you for your expertise and efforts to bring us better knowledge about the science surrounding these topics. I too am skeptical of the audibility, but always willing to learn. 

Same here.

 

[jnjn]

Ya know, I missed this....sorry.
Quote:

Not sure if anyone has posted this yet - but this is a very interesting article: http://en.goldenears.net/index.php?mid=KB_Columns&document_srl=1301
 
Basically with cables, the more I read, the more I realise how little I actually understand electronics.  Another interesting cable review with measurements: http://www.hometheaterhifi.com/volume_14_4/legenburg-zeus-cables-12-2007.html
 
I am starting to worry - I just bought $60 worth or rectangular OCC copper for a HE-6 recable (mostly because stock cable is oxidising) but I am starting to think I would have been better off using round wires in star quad, just keeping the gauge under 26 AWG (in order that the wire is less than 20 kHz skin depth - at least if I got my calcs correct).  Anyway I'm glad I didn't buy ROCC silver which would have cost me about 5 times more...
 
So star quad seems to be the geometry which most pro-audio companies use for their cables?  I can do this construction with my rectangular wire and just hope the capacitance isn't too high.
 
As far as I can get my head around it, phase and temporal distortion seems to be the main concerns in designing audio cables, but for the life of me I don't see how conductor metallurgy has anything to do with this, but then again I am not really an expert in any field which would cover this.  From my understanding, conductor purity/metallurgy has an influence over signal propagation speed, but I have no idea how this would affect critical performance metrics (in my understanding) such as phase distortion.
 
You would think that cable manufacturers, given how ready they are to publish scientific justifications for their cable products, would participate more in threads such as this.  Presumably, given their marketing material, they must employ at least a couple of engineers or scientists.  When people start wrongly representing other products, more often than not a rep from the company notices and chimes in to set things straight.  Maybe we just need to drop a few company names?

The exponential skin depth approximation is not very good, you really need to use the bessels in this regime, and I don't wish that on anybody.  At 20Khz, the current density drop of even a 1mm diameter wire is not that much.  So the resistivity of the conductor and the internal inductance just isn't changing significantly, nor will the cable impedance or prop velocity.
 
The capacitance of a constrained cable is defined by a simple equation..  LC = 1034 * DC.  L in nH per foot, C in pf per foot, DC is the relative dielectric coefficient of the insulation.  (3 is typical for many non foamed plastics.)
 
For an unconstrained cable, you have to substitute the tern EDC, or effective dielectric coefficient, for DC.  Typically, a zip will run in the 4 to perhaps 6 range, based on the conductor spacing.
 
EDC cannot be below 1, as the prop velocity is V = Cv /sqr(EDC),  (Cv being lightspeed)
 
In general, a wire pair close together will have an L per foot of about 180 nH. 
 
In the star quad geometry done right, you can halve the inductance figure, or about 90 nH per foot...capacitance will be still defined by the equation with EDC about 4-6.  edit:  Done right, the star quad has the current in the wires such that the magnetic fields of each pair do not add, but are orthogonal.  Once orthogonal, the inductances are in parallel so do not enhance the field.  It's like putting two inductors in parallel....the end terminal inductance becomes half as long as the inductors do not communicate magnetically.
 
Cable vendor white papers many times are not written by a technical person.  Marketing is the primary source...there are of course exceptions.  THere is no advantage to a cable vendor going on forum to defend what they've written, and much to lose.  So they will not engage.
 
Sometimes, the papers are written by a technical person, but even then there is no guarantee that they have any understanding of what they've written.
 
jnjn

 

[Freefallr4545]

LOL These discussions are funny. ....Just my 2 cents (lovingly) Science is very limited

 

[Magick Man]

Polite discourse?  All along you've been treating me in a not so pleasant fashion.   You and many others tend to classify individuals in one of two categories, those that agree with you, and those that have their heads screwed on backwards.

Go back and review your posts.

I did go back and read them, I was thoroughly polite, even going out of my way to do so.

My stance is that an audible difference between properly made cables has never been proven, which is correct, and you counter by brow-beating and attempting to drown me out. If there are peer reviewed results that show otherwise, I'd be more than happy to amend my statements.

 

[bigshot]

Unfortunately, I see that on both sides of the argument.

A person who is investing his self worth in a stereo system is going to have much more reason to defend non-existent differences between cables or CD players. A person who is more interested in scientific testing will probably care less about people who believe cables have a sound than people who dismiss the value of scientific testing.

I'm with you, though. The back and forth is due to the way both sides frame their arguments. I wish the focus was on how to make significant improvements to the sound quality of stereo equipment instead of pissing matches about testing methodology and undefined numbers on a page. Even if one believes there is a difference between cables, the fact that no one has been able to decisively prove that indicates that the difference is going to be so small, it probably doesn't matter.

 

[jnjn]

Quote:

 
Oddly - that is the exact opposite of my experience. 
 
Regardless - though I do not understand it fully, I thank you for your expertise and efforts to bring us better knowledge about the science surrounding these topics. I too am skeptical of the audibility, but always willing to learn. 

I believe it is because I am an equal opportunity skeptic.  Despite the nature of the claim presented, I believe it important to question the validity of it.  To me, it is even more important to question technical claims, as that is where I come from.
Quote:

Feel free to provide more scientifically, more controlled, less idiotic tests that show audible differences. Good luck.

It's trivial to provide the electrical tests, I've done that over the years.  It is more difficult explaining those tests and why they are important.
 
For audibility, that is far more difficult.  Nature of the beast is one thing.  Human adaptation to localization cues is not clearly defined with respect to timeframe, integrated exposure, or even the time constant for the adaptation.  Greisinger has done some good work, some others are doing some really interesting work on time dependency of localization vs sweep speed through the listener's field..  But given the methodology of level only pan pot image location, I see many hurdles which are not going to be easy to solve.
 
For interconnects, the most important thing we need to do is understand why the equipment is sensitive to them, and fix the equipment...now that's something to take a bite of.
 
cheers, jnjn

 

[bigshot]

For audibility, that is far more difficult.

Audibility is the only thing that matters. The rest is all hot air.