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Stereophile article on speaker wire measurements

smallricey

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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?
If you read the thread, NTK's did not miss the mark. I'm suppose to summarize the article when I ask a question now?
Since you are pointing out that I have entered the shrine of "cult of science,"
then please show me who else provided valid scienctific discussion on this topic other than NTK. lol wth
 

Cbdb2

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Unfortunately today we have interference at much lower frequencies than those used in FM radio. As low as ... 9 kHz, that is, within the range reproduced by the speakers or in which the audio electronics work!

Theres a reason radio signals are in RF. Antenaes need to be wavelengh size, including the transmiter, so if your speaker cables are 100 meters long and somehow someone is transmitting on a huge antenae you might get some 9k. Look into submarine radio.
 

Cbdb2

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The Hawksford paper has been shown to be full of holes including his math so using that as a basis for the experiment is foolish, but I guess it helps sell this experiment. And the test signal is a basically a square wave so they should have filtered out the ultra sonics. In 30 years of editing music, dialoge and sound efects Ive never seen a waveform cutoff like there test signal.
 

Cbdb2

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? 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.

Theory by anyone ( Phds arent perfect) needs to be peer reviewed and tested properly. Why dont you do the math and see if its correct. That would help make your point.
 

maty

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Theres a reason radio signals are in RF. Antenaes need to be wavelengh size, including the transmiter, so if your speaker cables are 100 meters long and somehow someone is transmitting on a huge antenae you might get some 9k. Look into submarine radio.

Obviously the wavelength is very large and a very long cable would be required.

When I wrote that comment I was thinking about RF / EMI in general. The new home lighting, imported from Asia usually does not comply with the standards -> the electricity grid is getting dirty, down to 9 kHz.
 

Cbdb2

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Im confused. Are we talking power cables now? Otherwise its still low freq EM transmission and very little is transmitted or picked up.
 

Cbdb2

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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

Nicely shown. Would like to see the difference changing the cable R has. The cables tested seem to have a 2/1 difference in R,(from there mm^2) they dont tell you, nor cap/inductance, why not? The larger cables, lower R, "tested worse" R always reduces ringing. Is this the same as adding a resistor to your cable? Why would anyone do that?

Fairly simple questions easy to answer. And an amatuer comes up with them in 10 minutes but the experts never go there. Theres a reason these "papers" are only printed in audio rags.
 

smallricey

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Theory by anyone ( Phds arent perfect) needs to be peer reviewed and tested properly. Why dont you do the math and see if its correct. That would help make your point.
I could, then that would take time. That's why I asked the question to save time.
I find it hard to believe that anyone could take "couple of courses" on the subject and start peer review published paper.
Even if that's a valid suggestion, that would take tremendous amount of time. So what's the point to suggesting it.

Anyway, I think the discussion has turned toward a right direction, instead of just bunch of sarcasm without actual content.
 

escksu

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I'm not clear if you're Danny Richie or someone else is and you're just sharing it.

The video doesn't show anything except for ways of making a better antennae. You could take the same cable and twist it and you'll get better/worse reception depending on how you twist it around. Not sure why anyone would try to equate an antennae with sound differences in cables.

Its because all cables are basically antennas!! What he is showing is how RF interference affects cables (be it interconnect or speaker wires or even power cables). Noise is a big big issue in cables, even more so for network cables. Thats why you need twisted pair for noise rejection. Then its not enough for higher speeds, you need separation of the wires and additional shielding (mainly foil shielding). And then, even with all the stuffs, there is still a limit to how long the cables can go before you need a repeater. Thats why fiber is needed for long distances.
 

Cbdb2

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Not really. All cables are antenaes, but most are very poor antenaes. Good antenaes are single wires or loops with large areas, cables are neither. Cat6 etc. is rarely shielded and can run 200Mhz 300' in large bundles in industrial locations with no noise problems. The ballanced twisted cable is all you need. For 6' of low freq audio cable in a residential location noise is not a problem. If it is, its easily filtered out.
 

Speedskater

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Retired Audio Engineering Society interference expert Jim Brown writes:
Antenna Action
The most fundamental cause of radio interference to other systems is the fact that
the wiring for those systems, both inside and outside the box, are antennas. We may call them
"patch cables" or "speaker cables" or "video cables" or "Ethernet cables," or printed circuit traces,
but Mother Nature knows that they are antennas! And Mother Nature always wins the argument.


But, and it's a big but. It takes almost Perfect Storm conditions for this to happen in an audio system.
1] The interference has to be present.
2] An audio component has to be sensitive to interference at that frequency.
3] The cord or cable has to have a length and placement to act as an interference antenna.
 

teched58

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Retired Audio Engineering Society interference expert Jim Brown writes:
Antenna Action
The most fundamental cause of radio interference to other systems is the fact that
the wiring for those systems, both inside and outside the box, are antennas. We may call them
"patch cables" or "speaker cables" or "video cables" or "Ethernet cables," or printed circuit traces,
but Mother Nature knows that they are antennas! And Mother Nature always wins the argument.


But, and it's a big but. It takes almost Perfect Storm conditions for this to happen in an audio system.
1] The interference has to be present.
2] An audio component has to be sensitive to interference at that frequency.
3] The cord or cable has to have a length and placement to act as an interference antenna.

It's not a "big but," nor does it require a perfect storm. Just put your iPhone next to your receiver/amplifier; when it registers with the tower, you will hear the RFI through your speakers. (Yes, I know, you're not "hearing" RF, you're hearing rectified interference. bbbzzzzzzzzzzz,,,bbbbbbbzzzzzzzzzzzz,)
 

DonH56

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It's not a "big but," nor does it require a perfect storm. Just put your iPhone next to your receiver/amplifier; when it registers with the tower, you will hear the RFI through your speakers. (Yes, I know, you're not "hearing" RF, you're hearing rectified interference. bbbzzzzzzzzzzz,,,bbbbbbbzzzzzzzzzzzz,)

I don't have an iPhone but my Android does not do that. Not sure if your components need better RFI suppression or you need a different phone. :) That said, while I did exactly that experiment in the past, I have not tried it with my new processor. For the HT world, there is so much noise inside the box, that suppression pretty much has to be in there or nobody would buy the things...

One additional factor is the impedance of the circuit. Inputs sometimes include small (low-value) capacitors to suppress HF noise (RFI). Outputs are usually low enough in impedance and filtered enough to not need them but the sneak path from speaker cable through amp via the feedback path is fairly common (and easy to fix, but manufacturers can save a cap or two). Preamps usually have a series resistor of 100~1000 ohms at the output and internal capacitance may be enough to kill RFI.
 

Inner Space

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Retired Audio Engineering Society interference expert Jim Brown writes:
Antenna Action
The most fundamental cause of radio interference to other systems is the fact that
the wiring for those systems, both inside and outside the box, are antennas. We may call them
"patch cables" or "speaker cables" or "video cables" or "Ethernet cables," or printed circuit traces,
but Mother Nature knows that they are antennas! And Mother Nature always wins the argument.


But, and it's a big but. It takes almost Perfect Storm conditions for this to happen in an audio system.
1] The interference has to be present.
2] An audio component has to be sensitive to interference at that frequency.
3] The cord or cable has to have a length and placement to act as an interference antenna.

I believe this "big but" is correct. Ten years ago I lived only in NYC, 11 blocks south of the Empire State Building, with a direct line-of-sight out my window. IIRC there were more than 420 transmitters up there (the WTC having been destroyed), some of them very high power. I messed around with dozens of different sources and headphone amps for months, and only once had an RFI problem, with one particular Luxman tube amp. Empirical only, but for me RFI hasn't presented a real-world problem.
 

maty

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Talking about phones, more than once the noise of the mobile phone slips in when receiving a call while it is doing a vinyl ripping. I guess because of the phono and the cables.
 
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