Blind Listening Tests & Amplifiers

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diyAudio Senior Member
Joined 2002
Hi,

Remember, I said with the same LCR properties.

No offense, but are all Ls, Cs and Rs created equal?

They still measure the same if measured only for that particular parameter, don't they?

All this somehow reminds of the old engineering adagio that said :

A resistor is a resistor is a resistor...

I would certainly hope we know better than that by now?

You guys on the other hand are trying to hear a difference, so your results would be more credible than mine.

I don't think so, whatever way you're biased the audible differences are so obvious, they're really hard to ignore.

Oh, I don't have any trouble at all designing cables that have the same measured L,R and C values and would still sound totally different from one another...easy.

Cheers,;)
 
Ummmmm

Zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz hrrrm! :)

Why is it so fxxxing hard for some people to realise that cables have their own sounds, I´m getting sooo tired of this closed minded people.

Me and a friend set out to do a BLT to convince him that I easily could tell the cables apart and also to report back to a thick-headed non-believer on another board.

Because of the way my system is set up we decided to do a quick switch back and forth just to get the initial feel for the difference. As I experienced so many times before, the difference we both heard was so obvious it was totally silly to go ahead and waste time in a blind test.

Get this into your head non-believers, audiocables such as IC´s and speakercables have their own unicque (how about that spelling :)) sound which makes it worthwhile to experiment with different cables if you want to draw the last bit of performance out of your rig. This is true even for short lengths of 0.5-1 meter or even shorter.

/Peter
 
Re: Ummmmm

Pan said:
Why is it so fxxxing hard for some people to realise that cables have their own sounds, I´m getting sooo tired of this closed minded people.

And how open-minded is it for one to be in complete denial of the very real psychological aspects which have been shown over and over again to cause differences to be perceived even when none exist? I don't know about you but this seems rather closed-minded to me.

Me and a friend set out to do a BLT to convince him that I easily could tell the cables apart and also to report back to a thick-headed non-believer on another board.

Because of the way my system is set up we decided to do a quick switch back and forth just to get the initial feel for the difference. As I experienced so many times before, the difference we both heard was so obvious it was totally silly to go ahead and waste time in a blind test.

Yet those just as confident as you and your friend, when tested under blind conditions, have done no better than if they were simply guessing.

Similarly, others are just as confident that placing photographs of themselves in their freezers also produces differences as obvious as those you claim here.

Talk is cheap. There has been literally DECADES of talk along these lines. When is someone finally going to stop flapping their gums and step up to the plate and just prove it once and for all so we can put an end to this debate and move on to something more productive? Why are we still here some 30 years hence arguing about it if it's as obvious as you say? It should have been put to rest long ago.

Get this into your head non-believers, audiocables such as IC´s and speakercables have their own unicque (how about that spelling :)) sound which makes it worthwhile to experiment with different cables if you want to draw the last bit of performance out of your rig. This is true even for short lengths of 0.5-1 meter or even shorter.

Once again, talk is cheap. Your claims have no more validity than those of the "non-believers." Just another of the tens of thousands who have come before you.

Instead of just being another face in the crowd, why don't you become "the one"? Don't wait around for some bald black guy in a duster and shades to offer you some pills. You already claim to know how deep the rabbit hole goes. It would be ground-breaking.

Or are we to have yet another bacth of excuses leading to another 30 years of "Tastes great!" "Less filling!"?

And for the record (which includes a public record of posts going back 20 years), I hold no particular beliefs on this issue one way or the other. My fasciation with this issue relates to my fascination with religious fundamentalism and what causes otherwise seemingly rational people to become so frighteningly irrational.

So anyone thinking of trying to pigeonhole me into some simpleminded black and white "believer/non-believer," "yaysayer/naysayer" slot can just forget about it.

se
 
Informal Proof.

An experiment that I performed 10 years ago showed me that dielectrics can make a sonic difference in an interconnect.
The IC concerned consisted of 4 solid-core wires in star quad configuration arranged around a 4mm diameter stiff plastic rod, all sourced from stripped down Apogee IC cable.
The individual wires originally were clad in teflon sleeves, which were retained in the first experiment, and the the four wires and rod wrapped with Teflon plumbers tape.
Second experiment was to swap the teflon tape for standard office cellotape.
Third experiment was to remove the teflon sleeves and re-wrap with teflon tape.
Fourth experiment was as above and cellotape wrap.
Fifth experiment was to remove all wrappings and center rod, and the wires uninsulated and air spaced.
All configurations sounded different, with the teflon causing a hardness/brightness, and the cellotape causing a different crackly brightness.
Electrically all configurations ought to have measured (I did not do so) the same because the same wires were used and with the same spacing, however all five configurations sounded significantly different to each other, and all configurations sounded wildly different to the original cable assembly.
The factor accounting for sonic differences can only be differing dielctric materials.

Eric.
 
R, L, C and G are more far-reaching than some may realize

PMFJI, but I wanted to interject something regarding the importance of R, L, C and (it seems to have been left out in some posts) G. Some folks are apparently of the view that these parameters are some kind of lumped circuit approximation to the actual wave propagation that occurs. These parameters actually fully represent the wave propagation, and are totally consistent with Maxwell's equations for the TEM mode of propagation in a transmission line.

The important thing is, these parameters are not resistance, inductance, capacitance and conductance, but rather resistance, inductance, capacitance and conductance per unit length. This does not mean that you take these numbers, multiply them by the length of the cable and get a single resistance, inductance, capacitance and conductance value. It means that each infinitesimally short section of cable has an incremental series resistance and inductance, and an incremental shunt conductance and capacitance.

The equations representing this structure are derived by taking the limit as this incremental length approaches zero. This is illustrated here:

http://emlab2.nmsu.edu/classes/ee315/tl/node2.html

Notice that the current and voltage are expressed as a function of both position and time. The two equations that result are combined into one, as shown here:

http://emlab2.nmsu.edu/classes/ee315/tl/node3.html

The equation that results is a wave equation, not a simplified lumped circuit equivalent.

Further information can be found here:
http://www.ece.uci.edu/eceware/hspice_docs/hspice_and_qrg/hspice_2001_2-124.html#14853

Now R, L, C and G are in general functions of frequency, but knowing all these parameters over a broad bandwidth that includes the audio frequency range gives a very accurate representation of the wave propagation in the cable at those frequencies.

So if someone tells you that R, L, C and G don't fully describe the electrical properties of a cable, it's likely that they don't understand transmission line theory. Be aware also that Maxwell's equations, used up to hundreds of GHz, don't even attempt to describe what happens to individual electrons (that's quantum theory). Instead, they deal with continuous charge distributions rather than discrete electrons for example. Yet given the appropriate transmission line models, Maxwell's equations have been shown time and time again to yield results as close to measured data as can be physically achieved.

So if quantum theory is not necessary to accurately describe wave propagation in the millimeter wave region, it's unlikely that it should be necessary in the audio range.

So save your money! There's lots of DIY cable recipes on the net that are based on sound (no pun intended) engineering (low inductance, reduction of high-frequency losses by using multiple insulated wires of small diameter, etc.). I see no reason why these designs can't be sonically as good as any cable that could be bought, regardless of price.
 
Originally written by mrfeedback
Electrically all configurations ought to have measured (I did not do so) the same because the same wires were used and with the same spacing, however all five configurations sounded significantly different to each other, and all configurations sounded wildly different to the original cable assembly.
The factor accounting for sonic differences can only be differing dielctric materials.

Hi Eric,
It's likely that the dielectric constants were different between the two materials (cellotape vs. teflon). The relative dielectric constant of teflon is around 2.2, but I don't know about the cellotape. I suspect it's higher. Different dielectric constants mean different capacitance per unit length. Think of the parallel plate capacitor where:

C = (epsilon * A) / d

where epsilon is the dielectric constant, A is the area, and d is the separation. If A = length * width, you can see that the capacitance per unit length is proportional to the dielectric constant. Also, it's likely that the shunt conductance loss is higher in the cellotape than the teflon. Teflon is very low loss. It's often used for circuit boards in the microwave frequency range. So what I'm saying is it's likely that the cables would have measured differently because of the different capacitance per unit length, which results from the different dielectric constants of the materials.
 
Re: R, L, C and G are more far-reaching than some may realize

andy_c said:
So if someone tells you that R, L, C and G don't fully describe the electrical properties of a cable, it's likely that they don't understand transmission line theory.

And if someone were to say that R, L, C and G DO fully describe the electrical properties of a cable, would it be fair to say that they don't understand that R, L, C and G are idealized elements and only fully describe an idealized cable and do not fully describe realworld cables which use non-idealized conductors and dielectrics? ;)

se
 
Hi Andy,
I agree and confer with what you say here.
However in these and other experiments I have found teflon to impart a particular sonic signature, and further according to the pigments loaded into the teflon.
Sure I expect these pigments to alter the Dielectric Constant, and also the Dissipation Factor of these dielectric materials.
Is this a further cause of these sonic changes ?.

Eric.
 
Eric,
I haven't a clue regarding the pigments and their effect (or not) on the dielectric constant and losses. I do know that there are many different variations of teflon, like this one, which is quartz-loaded:

http://www.rogers-corp.com/mwu/pdf/6002data.pdf

with a dielectric constant of 2.94, and this one:

http://www.rogers-corp.com/mwu/pdf/5000data.pdf

with a dielectric constant of 2.2. But to tell the truth, I've not seen dielectric constant measurements of the teflon insulating material used on typical hookup wire. I've just assumed (maybe incorrectly) that it's similar to the 5880 microwave laminate that isn't loaded with quartz.

It's too bad the pads lift so easily on these Rogers materials, because they are really high quality. Expensive too.
 
andy_c said:
I haven't a clue regarding the pigments and their effect (or not) on the dielectric constant and losses.

Belden had a write-up about this but I'll be damned if I can find it at the moment. I'll keep looking.

It's hardly any leap of logic given that the pigments used will have different dielectric properties than the dielectrics they're being used to color and it would be expected that the combination of the two would alter the characteristics of the primary dielectric.

se
 
Steve Eddy

Numbers of blind tests have ben done which clearly proove that people can distuinguish cables with very similar parameters from eachother. Non-believers are free to keep their head burried in the sand refusing to open their minds for new knowledge, in the end it´s their loss.

Latest test I know about can be found at the Madisound board.

BTW I´m very openminded IMO, In the beginning of my audio days I DID NOT hear difference between cables whatsoever. But I was curious about the issue so after several years I tried again and by then my rig was of much higher resolution and suddenly it was perfectly possible to hear the difference between cables.

/Peter
 
Deam blind tests

Oh well...
As some of you might remember (or not), I reported several blind tests I made with cables.
I've spoken about this one, but there it goes again.
I visited a friend of mine at an hi-fi distributor (make it high-end) with a pair or my diy cables (Cat.5 and cheap gold-plated plugs) on my hand.
I asked him to compare them to a commercial product.
He was very sceptic and called me crazy.
Then he connected my cables in a system.
The cd-player had two line outs and it was my cable on one and some WireWorld (80 euros) cable on the other.
I asked him where were my cables connected (the preamp input) and he said: "I won't tell you, you'll have to figure out what's the best cable".
In the end we ageed my cable was vastly supperior.
The difference was that he was sceptic at the begining, and he knew what cable was playing everytime.
I didn't know, and easilly detected the best cable.
it was my cable, but it could be the other, that doesn't matter. The fact was that I detected the best cable.

THIS IS A PURE BLIND TEST.
BUT SOME PEOPLE ARE DEEEEEEEEEEEEEEEEEEEEAF!:devily:


With speaker cables the difference in sound is even greater, even the cheap ones!:nod:
 
Re: Oh, what the heck, one more try.

Christopher said:
Remember, I said with the same LCR properties.

> The simplest example I can think of is the length.


How?


To justify my original post, I claimed the length of a cable affects its physics (i.e. measurable, electrical, properties) without being easily related to a simple trinity of L, C and R values.

Also, it is a mistake to think that if you connect a capacitance meter up to the a cable and it measures 100pF, that the cable is automatically equivalent to an ideal 100pF capacitor. The latest board I'm doing at work has 100-odd 100nF PSU decoupling capacitors on it; it will measure the same as a single 10uF electrolytic, but I promise you they're not equivalent!

So I'm open to the idea of cables having properties not showing up in multimeter L,C,R measurements, although I believe I never claimed any to be audible. (In fact, I specifically claimed microphony to be inaudible).

Like you, I have no truck with the science fiction babble associated with high-end cables. But if you're proposing that an LCR bridge will tell you everything you need to know about a cable, I have to disagree - such a claim is theoretically unsound.

Cheers
IH
 
Re: Re: Oh, what the heck, one more try.

IanHarvey said:
Christopher said:
Remember, I said with the same LCR properties.

> The simplest example I can think of is the length.


How?


To justify my original post, I claimed the length of a cable affects its physics (i.e. measurable, electrical, properties) without being easily related to a simple trinity of L, C and R values.

Also, it is a mistake to think that if you connect a capacitance meter up to the a cable and it measures 100pF, that the cable is automatically equivalent to an ideal 100pF capacitor. The latest board I'm doing at work has 100-odd 100nF PSU decoupling capacitors on it; it will measure the same as a single 10uF electrolytic, but I promise you they're not equivalent!

So I'm open to the idea of cables having properties not showing up in multimeter L,C,R measurements, although I believe I never claimed any to be audible. (In fact, I specifically claimed microphony to be inaudible).

Like you, I have no truck with the science fiction babble associated with high-end cables. But if you're proposing that an LCR bridge will tell you everything you need to know about a cable, I have to disagree - such a claim is theoretically unsound.

Cheers
IH

Agree, some think that a cable is a simple combination of ONE C, ONE L and ONE L, common folks....

A cable is a infinately great numbers of RCL circuits connected in series with eachother, since the "values" of the R, C and L are distributed along the entire length of the cable.

So instead of being a simple second order lowpass it is more akin to a "infini-slope" with ´the associated phase response.

/Peter
 
Re: Steve Eddy

Pan said:
Numbers of blind tests have ben done which clearly proove that people can distuinguish cables with very similar parameters from eachother.

Can you cite a few of those, please?

It's actually quite easy to construct tests which give positive results. That's because even very subtle cues which have nothing to do with the cables themselves can skew the results.

I recall one instance where a test was run which gave positive results but upon further examination, it was found that just a very slight difference in the sound of the switch (i.e. there was a difference in the sound of the switch when switching to A versus switching to B) being used to conduct the tests. When the sound of the switch was eliminated and the test run again, no statistically significant differences were found.

Non-believers are free to keep their head burried in the sand refusing to open their minds for new knowledge, in the end it´s their loss.

That presupposes that there is in fact new knowledge. Remember Pons and Fleischman?

And again, I'm neither a believer nor a non-believer.

Latest test I know about can be found at the Madisound board.

Where exactly? Can you post a specific URL?

BTW I´m very openminded IMO, In the beginning of my audio days I DID NOT hear difference between cables whatsoever. But I was curious about the issue so after several years I tried again and by then my rig was of much higher resolution and suddenly it was perfectly possible to hear the difference between cables.

That's fine. But people subjectively perceiving differences in and of itself does not constitute proof of anything.

se
 
Re: Re: Re: Oh, what the heck, one more try.

Pan said:
Agree, some think that a cable is a simple combination of ONE C, ONE L and ONE L, common folks....

A cable is a infinately great numbers of RCL circuits connected in series with eachother, since the "values" of the R, C and L are distributed along the entire length of the cable.

And that's all well and good when your wavelengths approach the length of the cable. But when your shortest wavelength is on the order of 10 miles and your cable is only several feet long, distributed parameters are rather meaningless.

So instead of being a simple second order lowpass it is more akin to a "infini-slope" with ´the associated phase response.

Yet that infinite slope and associated phase response has never been observed, even though it would be trivially measurable.

I think you need to go back and review distributed parameter modeling.

se
 
To Steve Eddy

carlosfm said:
Oh well...
As some of you might remember (or not), I reported several blind tests I made with cables.
I've spoken about this one, but there it goes again.
I visited a friend of mine at an hi-fi distributor (make it high-end) with a pair or my diy cables (Cat.5 and cheap gold-plated plugs) on my hand.
I asked him to compare them to a commercial product.
He was very sceptic and called me crazy.
Then he connected my cables in a system.
The cd-player had two line outs and it was my cable on one and some WireWorld (80 euros) cable on the other.
I asked him where were my cables connected (the preamp input) and he said: "I won't tell you, you'll have to figure out what's the best cable".
In the end we ageed my cable was vastly supperior.
The difference was that he was sceptic at the begining, and he knew what cable was playing everytime.
I didn't know, and easilly detected the best cable.
it was my cable, but it could be the other, that doesn't matter. The fact was that I detected the best cable.

THIS IS A PURE BLIND TEST.
BUT SOME PEOPLE ARE DEEEEEEEEEEEEEEEEEEEEAF!:devily:


With speaker cables the difference in sound is even greater, even the cheap ones!:nod:

Unforyunately, I have to quote myself...


Steve Eddy said:


Can you cite a few of those, please?

It's actually quite easy to construct tests which give positive results. That's because even very subtle cues which have nothing to do with the cables themselves can skew the results.

I recall one instance where a test was run which gave positive results but upon further examination, it was found that just a very slight difference in the sound of the switch (i.e. there was a difference in the sound of the switch when switching to A versus switching to B) being used to conduct the tests. When the sound of the switch was eliminated and the test run again, no statistically significant differences were found.


ARE YOU BLIND, STEVE?
Didn't you see my post in this page?
Are you saying that the two fixed line outs of the cd-player sound different, or the two line-ins on the preamp?
No switch here!
Peter is right, some people just don't want to believe.
It's a lost case.
Besides deaf and close minded, people get blind.
I'll write in Braile from now on. :rolleyes:
 
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