Stereophile article on speaker wire measurements

[Wes]

"audio waves" ??

 

[smallricey]

obscure?

 

[NTK]

The question I'd like to ask the writer of the Stereophile article is why was there no hypothesis given to try explaining what was happening. Isn't that what most scientists do? Make an observation, then theorize why it happened, and then test the theory to see if it can be generalized and apply to other operating conditions and make the theory useful.

Look at the last Figs 27 & 28 (the last 2 figures). When the test speaker was replaced an 8 ohm resistor, the ringing magnitudes were much diminished and I can hardly tell any differences between the "best" and the "worst" cables. Why wasn't any hypothesis or explanations (or even discussions) given?

I constructed a highly simplified and idealized model with OpenModelica. The cable was modeled with a 0.1 ohm resistance, 7 uH inductance, and 1000 pF capacitance. The loudspeaker load was simulated using the model given in this link (but with R1 set to 6 ohm):
http://www.aikenamps.com/index.php/designing-a-reactive-speaker-load-emulator

The 1 kHz results are attached. It showed that the type of behaviors in the Stereophile test can be easily simulated. The differences/deviations are not unexpected since the Stereophile graphs were generated using a real (and non-ideal) amplifier and a real speaker, and I've made no attempt to tweak the simulations parameters to match.

So what's going on in the Stereophile test? It is simply that when the tone bursts stopped, the speaker could not "stop" immediately. The combination of the speaker driver inertia and stored energy in the capacitors and inductors generated a back EMF. And what were shown in the traces were the voltage drop across the speaker cable due to the back EMF (when the back EMF is shunted through the output impedance of the amplifier).

So what effects will this have on the sound radiated by the speaker? The real test is to use either measure the sound pressure with an instrument mic, or use a laser vibrometer to measure the displace of the speaker diaphragm. If you do that, you will find out that the effects of the cables are either not measurable or totally negligible. They will be totally overwhelmed by the mechanical responses of the drivers.

This are all elementary stuff.

 

[smallricey]

The question I'd like to ask the writer of the Stereophile article is why was there no hypothesis given to try explaining what was happening. Isn't that what most scientists do? Make an observation, then theorize why it happened, and then test the theory to see if it can be generalized and apply to other operating conditions and make the theory useful.

Look at the last Figs 27 & 28 (the last 2 figures). When the test speaker was replaced an 8 ohm resistor, the ringing magnitudes were much diminished and I can hardly tell any differences between the "best" and the "worst" cables. Why wasn't any hypothesis or explanations (or even discussions) given?

I constructed a highly simplified and idealized model with OpenModelica. The cable was modeled with a 0.1 ohm resistance, 7 uH inductance, and 1000 pF capacitance. The loudspeaker load was simulated using the model given in this link (but with R1 set to 6 ohm):
http://www.aikenamps.com/index.php/designing-a-reactive-speaker-load-emulator

The 1 kHz results are attached. It showed that the type of behaviors in the Stereophile test can be easily simulated. The differences/deviations are not unexpected since the Stereophile graphs were generated using a real (and non-ideal) amplifier and a real speaker, and I've made no attempt to tweak the simulations parameters to match.

So what's going on in the Stereophile test? It is simply that when the tone bursts stopped, the speaker could not "stop" immediately. The combination of the speaker driver inertia and stored energy in the capacitors and inductors generated a back EMF. And what were shown in the traces were the voltage drop across the speaker cable due to the back EMF (when the back EMF is shunted through the output impedance of the amplifier).

So what effects will this have on the sound radiated by the speaker? The real test is to use either measure the sound pressure with an instrument mic, or use a laser vibrometer to measure the displace of the speaker diaphragm. If you do that, you will find out that the effects of the cables are either not measurable or totally negligible. They will be totally overwhelmed by the mechanical responses of the drivers.

This are all elementary stuff.
View attachment 72060 View attachment 72061 View attachment 72062

I thought the theory is given in the linked 1995 Maxwell equation article.

If what you are saying are true. Then the same result cannot be replicated twice yah? It would be totally random?

 

[tomtoo]

I only suggested that you did not read the article because the 3ghz experiment had nothing to do with this experiment.
So I'm unsure why you mentioned it in the first place, and it's placed in the first sentence of the article.
So I think it makes a lot of sense to ask the question if you actually read the article or not.

My conclusion is the article clearly show the cable produce different waves, but like you said is it audible? I don't know. That's why I'm here.
Now, instead of scientific discussion I found jokes based on false claim.
Except one guy says wall absorption would make greater audible difference, which I agree.
That's a lot of false claim for 3 pages of comments. I thought this is a science forum not I choose which data I want to believe forum.

What about cables apply to headphone then, it would take the wall factor out of the equation.
Also, even if wall affect the sound greater than cable, it does not discredit this article a bit.
The room has greater affect to DAC are you going to discredit DAC now?

It looks like you do not know the answer either, or maybe you do know the answer but without sharing the experiment to back it up.
So what's the point to dismiss it?

I think the general consensus in this forum is as long as cables are working and you are not running 10meter cable you are good to go.
However, this article clearly disapproves that. Now if you have paper or scientific experiment says it's not audible then please share it.
Again, I thought this is a science forum not I choose which data I want to believe forum.
It's funny to call it an April fool joke when one really have nothing to show.
Maybe that's the 4th July spirit instead? Get drunk and spit out gibberish lol

Now i never told the 3ghz experiment had to do with the later measurements. You can see i did the extract with the date of 2008. But it it is in this articel for what???
This articel is horribly unscientific it just gives you the impression it shows that you can hear speakercable differences and that there is a prove couse you can measure differences. Shurly you can measure differences. You can easy measure different
LCR of cabels but this tells nothing about how much you can hear it.

Thats why i told they correlate venus phase with the taste of your cornflakes.

And no in germany 4. juli is no special day.

 

[smallricey]

Now i never told the 3ghz experiment had to do with the later measurements. You can see i did the extract with the date of 2008. But it it is in this articel for what???
This articel is horribly unscientific it just gives you the impression it shows that you can hear speakercable differences and that there is a prove couse you can measure differences. Shurly you can measure differences. You can easy measure different
LCR of cabels but this tells nothing about how much you can hear it.

Thats why i told they correlate venus phase with the taste of your cornflakes.

And no in germany 4. juli is no special day.

It seems like you cannot comprehend the article.
The figure was there to show what experiment has been done by Ben Duncan to prove PhD's theory.

Again, maybe it's the language barrier or difference in scientific method between Germany and US.
If you have a theory, you test it to see if your theory work. Is it applicable in real life is another matter seems perfectly valid.
Now, you can come out and claim that it does not matter in real life, like you are saying here by showing proof.
However, discredit the theory completely while not fully understand the article is "unscientific" using your own word.
Spitting out weird phrases like venus phase and cornflakes is another.

I think NTK is saying the measurement is not measuring wires' change in energy. It's measuring speaker driver's own energy.
If what he is saying is true then that obviously discredit the article. Great theory debunked.
Now, the article is showing measurements on 125hz, 1khz, etc....so whatever you are saying about 3ghz really has nothing to do with the article.
Again "Unscientific", whatever that means, unfortunately.

 

[NTK]

One has to question the writers of these articles. They put up some theories, but never seem willing or able to make the final (and crucial) connections to what their practical implications are.

Tertiary and quaternary effects were emphasized, but where are the discussions on their relative importance when compared to the primary and secondary effects?

I'll go back to the Stereophile cable article and explain it with a little more details. The test setup is shown below.

Channel 1 of the AP was connected close to the speaker terminals. Channel 2 was connected close to the amp. During the quiet period between the tone bursts, the speaker became the signal source and the amp became the "load". What were measured were the back drive voltages from the speaker measured near the speaker end of the cable and near the amp end of the cable. Because the output impedance of the amp is low, using the voltage divider formula, one can easily see that minor changes (in absolute values, not relative values) in the speaker cable impedance will show up as relatively large differences. Obviously a real amp doesn't just act like an ideal resistor, thus the resulting measured waveforms can get a bit more complicated.

But what are the relationship between these measurements and the actual motion of the speaker diaphragms? Isn't that what we should care about? No mentioning of it whatsoever, while much ink was spilled on other irrelevant things. It was the residual motions of the diaphragms, and energy release from the XO capacitors and inductors, that resulted in those measured voltages. Not the other way around. Little wonder when the speaker was replaced with a resistor, the "ringings" were greatly diminished and the "worst" and "best" cables showed essentially the same results. (Note that real life resistors have non-zero inductance and can "store" some energy.)

Obviously the test was contrived to show some "measurable effects" so they can point to it and say aha. Show some stuff that has no relevance, create theories without proving whether they have anything to do with real world. That's the playbook.

 

[Wes]

1. There is no difference in scientific method between Germany and US, or any where else.

2. The writer of the article is not a scientist.

3. The differences found are of no effect on audio.

 

[smallricey]

Obviously the test was contrived to show some "measurable effects" so they can point to it and say aha. Show some stuff that has no relevance, create theories without proving whether they have anything to do with real world. That's the playbook.

Sounds good to me, thanks

 

[smallricey]

1. There is no difference in scientific method between Germany and US, or any where else.

2. The writer of the article is not a scientist.

3. The differences found are of no effect on audio.

Would have mattered if there's actual content in these words lol...oh well can't all be scientist

 

[KeithPhantom]

2. The writer of the article is not a scientist.

Not to refute your point (I actually agree with your main point), but science is factual and it does not care about credentials. If a college freshman is able to present results proving a hypothesis by following the scientific method, the findings cannot be disregarded because a lack of credentials, peer and methodology review must be followed and critics must be done. I won't discredit him because he may lack the credentials, but the author must show the methodology and results to be repeated by the community, being scientific or not.

 

[Thomas savage]

Would have mattered if there's actual content in these words lol...oh well can't all be scientist

Dito

 

[tomtoo]

It seems like you cannot comprehend the article.
The figure was there to show what experiment has been done by Ben Duncan to prove PhD's theory.

Again, maybe it's the language barrier or difference in scientific method between Germany and US.
If you have a theory, you test it to see if your theory work. Is it applicable in real life is another matter seems perfectly valid.
Now, you can come out and claim that it does not matter in real life, like you are saying here by showing proof.
However, discredit the theory completely while not fully understand the article is "unscientific" using your own word.
Spitting out weird phrases like venus phase and cornflakes is another.

I think NTK is saying the measurement is not measuring wires' change in energy. It's measuring speaker driver's own energy.
If what he is saying is true then that obviously discredit the article. Great theory debunked.
Now, the article is showing measurements on 125hz, 1khz, etc....so whatever you are saying about 3ghz really has nothing to do with the article.
Again "Unscientific", whatever that means, unfortunately.

If someone likes to get me wrong even i explained my intention. He/ she will get me wrong. So i stop conversation.

 

[Speedskater]

Note that a test signal like this requires almost infinitely high frequency response. Nothing like this is possible in any digital audio system.

 

[KeithPhantom]

Wires are effectively filters at high frequencies, but those frequencies are nowhere near the audio frequencies or even our systems are susceptible to them. RF and MHz to GHz are where our regular copper cables start to be actual filters, but I don't think your cables can even pick up signals at that level (and if they do, most surely you won't hear them and intermodulation issues are going to be so far away from the audio band that they will be inaudible anyway).

 

[Wes]

Not to refute your point (I actually agree with your main point), but science is factual and it does not care about credentials. If a college freshman is able to present results proving a hypothesis by following the scientific method, the findings cannot be disregarded because a lack of credentials, peer and methodology review must be followed and critics must be done. I won't discredit him because he may lack the credentials, but the author must show the methodology and results to be repeated by the community, being scientific or not.

I don't know how an uneducated individual can do an experiment in modern science. Or even determine what experiment might be of interest in any field today.

Astronomy comes to mind, but that would primarily be observational, not experimental. Lots of amateurs collect data in bird popn studies or anthropology, but again they are not doing experiments.

It isn't credentials, which are just signposts or mileage markers or some such, it is education in the relevant field.


ricey - you might want to take some course work to help with your questions.

 

[KeithPhantom]

I don't know how an uneducated individual can do an experiment in modern science. Or even determine what experiment might be of interest in any field today.

Formal education is one way to standardize the trust you give someone in a field and to determine "experts". What I mean is you do not need to be an expert to have and interpret results. The scientific method was not created to be only used by credential holders, anyone who has the knowledge to apply a correct methodology, produce results, and share both to the public for further replication and criticism is applying science and their results cannot and must not be invalidated for a lack of credentials.

Modern science is just more complex, but it does not mean it isolates the ones without "proper credentials". Being uneducated does not correlate to not having a degree, it only means that a particular person does not have the knowledge required to direct and interpret experiments, knowledge that does not need to be obtained by formal education.

it is education in the relevant field.

Education can be self-obtained and self-taught, no need to go to an institution to get a paper that says that you are able to do something, anyone who understands the topic can use the scientific method to test any hypothesis.

 

[smallricey]

If someone likes to get me wrong even i explained my intention. He/ she will get me wrong. So i stop conversation.
ricey - you might want to take some course work to help with your questions.

? My field of study is in derived mathematics.
I don't intend to earn another degree for this hobby, especially the theory was derived by an PhD in the field.
It's really strange to see someone brush off a theory derived by a PhD and wants to take "some" course work to challenge an expert?

Honestly, that's really mind boggling.

 

[smallricey]

If someone likes to get me wrong even i explained my intention. He/ she will get me wrong. So i stop conversation.

Honestly, half of the time I have no idea about your intent.
I only posted here cause I want to find out some relevant information.
Unfortunately, I have not seen any relevant information from you.

I am not sure why people get so worked up about a valid theory being tested in this forum.
what is going on? It's almost like I have entered a cult lmao.

 

[Racheski]

Honestly, half of the time I have no idea about your intent.
I only posted here cause I want to find out some relevant information.
Unfortunately, I have not seen any relevant information from you.

I am not sure why people get so worked up about a valid theory being tested in this forum.
what is going on? It's almost like I have entered a cult lmao.

Your last sentence is the only statement that we agree on - you have entered a cult of science!

Since everyone here is off the mark on this article, why don't you help us out and summarize the article for some clarity? Specifically,

1. What is the author's hypothesis that he is testing, and what theory is it related to?
2. What data is the author measuring in his experiment?
3. What are the results of his experiment, and do they support the author's hypothesis?
4. What conclusions does the author draw based on the results of his experiment?
5. What is the peer review process that this article has undergone before it was published?