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Cables/Wires - Electrical Conduction Vs Magnetic Conduction

kach22i

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I am somewhat interested in opinions on cable/wire theory, not so much on how they sound, but the science and or philosophy behind the products.

Let's say the Jeff Smith/Hawksford is in "right field" (Electrical Conduction) and High Fidelity Cables (Magnetic Conduction) is in "left field".

What cable makers are in center field trying to do both?

Doesn't a good cable take both properties into account?

I am a novice at this, please explain it as you would to your mother. :)
 

SIY

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“Mom, both of them are peddling pseudoscience.”

Plain old wire works essentially perfectly for anything that’s not a pathological situation. Hawksford’s ramblings are misguided and sad, the other guys are as close to outright fraudulent as I’ve ever encountered.
 
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kach22i

kach22i

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“Mom, both of them are peddling pseudoscience.”

Plain old wire works essentially perfectly for anything that’s not a pathological situation. Hawksford’s ramblings are misguided and sad, the other guys are as close to outright fraudulent as I’ve ever encountered.
So what theory of sending an electromagnetic signal though a cable/wire do you abide by?

Can I have a link?

I have a challenge just thinking about electrons moving outside of the wire in a field, and not through the wire.

Where does resistance play in if the flow is outside the wire and not in it?

Is that the "skin effect"?

This PDF review on Silversmith is interesting in that a portion of it is more concise than other reading.

https://silversmithaudio.com/content/Reviews/i-audio7.pdf

Careful consideration.....................is the quote in the last paragraph of the first page found just above where it says "continues on page 45".

I find this explanation for using silver counter to the High Fidelity Cables explanation and I like the video in the High Fidelity Cables website very much. I just do not see the reasoning of favoring one theory of forces over another since both camps agree that the other indeed exists.

NOTE: Last night I read up to page 11 of the first Hawksford PDF (Essex Echo Summary), it put me to sleep, saving the rest for tonight as a sleep aid.
 
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SIY

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For low frequency signals, Ohm and Kirchoff are sufficient. The Essex Echo stuff was embarrassingly wrong.
If you want a better understanding of wire in audio, you can’t do better than the papers from Fred Davis and Dick Greiner. No pseudoscience there.
 

mansr

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So what theory of sending an electromagnetic signal though a cab;e/wire do you abide by?
Maxwell's. Electric charges and currents, electric fields, and magnetic fields are all interrelated. The equations describing a cable can be equivalently expressed in terms of electric fields, magnetic fields, or a combination of both. We normally choose the form that is easier to work with. There are no magnetic charges and hence no such thing as magnetic current/conduction.

At low frequencies, the equations simplify to the familiar Ohm's law. What are low frequencies, you may ask. The answer is those with wavelengths much longer than the wire. The velocity of propagation for electrical signals in typical wire is around 200 million m/s. The frequency range of audio signals is zero to 20 kHz, but let's be generous and extend it to 100 kHz. The wavelength at 100 kHz is 2 km. Wire lengths in home audio rarely exceed 10 m. In this context, 2 km is much longer than 10 m, so the simplified equations can safely be used. If you're wiring something like a stadium, things might be different. Old-style analogue telephone lines are another example where audio frequencies are not "low."

The articles you linked are all nonsense in concentrations that really ought to require a hazardous substance warning label.

Audio cables are a solved problem. Anyone claiming to have discovered something new is a fraud.
 

pozz

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So what theory of sending an electromagnetic signal though a cable/wire do you abide by?

Can I have a link?

I have a challenge just thinking about electrons moving outside of the wire in a field, and not through the wire.

Where does resistance play in if the flow is outside the wire and not in it?

Is that the "skin effect"?

This PDF review on Silversmith is interesting in that a portion of it is ore concise than other reading.

https://silversmithaudio.com/content/Reviews/i-audio7.pdf

Careful consideration.....................is the quote in the last paragraph of the first page found just above where it says "continues on page 45".

I find this explanation for using silver counter to the High Fidelity Cables explanation and I like the video in the High Fidelity Cables website very much. I just do not see the reasoning of favoring one theory of forces over another since both camps agree that the other indeed exists.
If you want to understand the minutia you will have to learn very high-level physics. There is no simple explanation. Philip Giddings' Audio Systems Design and Installation, the chapter on cabling, will have everything you need to know.

The "camps" you identified are part of the same camp. This is why their vocabulary and the issues they discuss tend to converge.

I took a quick read of these sites. The take-home version is this:
  • None of their claims show measurements of their designs vs. others either acoustically or electrically. They provide no proof other than the reviews of laymen. That's already reason to avoid their products.
The take-home-and-ponder version is this:
  • Electricity is not just flow of electrons, which actually move very slowly. The main force at work for flow is electromotive force. Electromotive force can induce current flow in conductors at a distance (for a practical example, look up a transformer).
  • In any conductor you have resistance R (an increasing value represents reduction of current flow), capacitace C (an increasing value represents higher storage of charges), and inductance L (an increasing value of which represents a stronger magnetic field around a conductor, which in turn means increased resistance to changing the direction of current inside a conductor—you will see why this is relevant soon). These values are interwoven and changing any aspect of conductor design will affect them.
  • Decreasing the resistance will increase the amount of passing current, which in audio means greater signal amplitude. All this means is that your speakers will be slightly louder. So if you go for silver vs. copper, you are effectively dealing with just that one property. Take note that silver conductors are much more fragile than copper conductors of the same length and thickness.
  • However, the details of electrical movement also show secondary effects, the most important one of which here is back EMF (counter-electromotive force), or what amounts to effective resistance to flow. For alternating current (AC), actual current flow will occur more at the edges of a conductor than at its center, where back EMF is stronger. This is "skin effect". Since conduction of audio signals through wire involves frequencies other than mains current (60Hz), note that skin effect is stronger at increasing frequencies. The reason skin effect is stronger is because of back EMF, which results due to the changing polarity of magnetic fields around a conductor. As frequency increases, the polarity changes more frequently and back EMF increases.
  • The way audiophile companies have dealt with skin effect is to take existing innovations in electrical engineering and magnify their scale to the point of absurdity. One way is to make the conductor effectively flat, which means that there is less of an actual center relative to the skin. Another is to use litz wire, which is a series of woven multistranded conductors, each of which is isolated from the other with an individual insulating coating. The High Fidelity Cables claim is to, apparently, force flow to occur at the center. They also claim that their products will cause the conductors in the rest of your system to act in the same way.
  • The caveat to all of this is that skin effect applies only at radio frequencies of 1MHz and higher. If you look at the spec sheets provided by Mogami, Belden and Canare, you'll see that they categorize their products based on their use, and the graphs they provide don't provide much of anything for audio frequencies of 20Hz—20kHz, where not much matters when using simple wire, but go into much greater detail for products meant specifically for RF or digital signals.
Other members with technical knowledge will correct any of the above where it's necessary (thanks in advance).

Edit: The phenomena @mansr described above are referred to as transmission line effects, which apply only to long-distance systems like telephone lines and the like.

Edit 2: I want to clarify that audio signals are AC, which means that current moves back-and-forth. This is where frequency comes in, with DC (unidirectional/direct current) having an effective frequency of 0Hz.
 
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DonH56

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I prefer my cables to operate in the TEM (transverse electrical magnetic) mode. As we exceed 40 GHz or so the cables are getting small enough that loss is a problem, but larger ones with lower loss exhibit non-TEM modes, affecting the signals. So if you are listening beyond 40 GHz you'll likely need to carefully consider your cables EM propagation. Below that, not so much. For audio, for reasonable lengths (like under a football field or ten), mostly what matters is the wire resistance and shielding.

RF transmission line propagation just does not matter at audio, but makes for good marketing copy.

Skin effect: https://www.audiosciencereview.com/...cle-does-audio-cable-skin-effect-matter.7157/
Transmission line effects: https://www.audiosciencereview.com/...-analysis-of-speaker-cables-reflections.7154/
Another on transmission line effects: https://www.audiosciencereview.com/...igital-audio-cable-reflections-and-dacs.7159/
Maxwell's equations: https://www.audiosciencereview.com/...ds/teaching-maxwell-equations-using-sex.1101/
 

RayDunzl

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My question of the day:

Does superconductivity affect the propagation speed of EMF in a conductor?
 
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kach22i

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Thank you for the replies gentlemen, I now have a few papers to read, names to look up, a few new terms to understand.

I am in no hurry to do so, this is just a hobby to me.

My experience with interconnect cables and speaker wires tells me there is an audible difference between designs/materials, but I don't know why.
 

DonH56

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My question of the day:

Does superconductivity affect the propagation speed of EMF in a conductor?

Going from old, old memories (I actually worked with superconductors for a short time, both for signal processing and to create microwave filters).

It's... complicated. Magnetic fields are essentially repelled (see e.g. Meissner Effect) and with zero resistance electrical fields become "funky". Propagation gets asymmetric IIRC with a couple of states/modes (that I do not recall off-hand) and the curves are non-linear. So, basically, "yes", but it is not zero if that's what you were thinking. Impinging magnetic fields over a certain critical level will shut down superconductivity (turning the path essentially into an open circuit); I believe that was the basis of the original cryotron element proposed for computers.
 

SIY

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My experience with interconnect cables and speaker wires tells me there is an audible difference between designs/materials, but I don't know why.

Generally because of sighted listening. Unless something is broken or seriously badly designed (e.g., thin speaker wires), ears-only evaluation shows that there’s no audible differences. The entire high end cable industry is built on quackery.
 

8lec

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I prefer my cables to operate in the TEM (transverse electrical magnetic) mode. As we exceed 40 GHz or so the cables are getting small enough that loss is a problem, but larger ones with lower loss exhibit non-TEM modes, affecting the signals. So if you are listening beyond 40 GHz you'll likely need to carefully consider your cables EM propagation. Below that, not so much. For audio, for reasonable lengths (like under a football field or ten), mostly what matters is the wire resistance and shielding.

RF transmission line propagation just does not matter at audio, but makes for good marketing copy.

Skin effect: https://www.audiosciencereview.com/...cle-does-audio-cable-skin-effect-matter.7157/
Transmission line effects: https://www.audiosciencereview.com/...-analysis-of-speaker-cables-reflections.7154/
Another on transmission line effects: https://www.audiosciencereview.com/...igital-audio-cable-reflections-and-dacs.7159/
Maxwell's equations: https://www.audiosciencereview.com/...ds/teaching-maxwell-equations-using-sex.1101/
Lmao, this made chuckle. Thanks dude :)
 

RayDunzl

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scott wurcer

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RF transmission line propagation just does not matter at audio, but makes for good marketing copy.

This is actually not exactly correct, there is only one physics, audio is just a limiting case. In fact if you model a cable with finite elements (R, L, C per unit length) you get exactly the same answer no matter how you look at it. The R, L, and C for the impedance and propagation velocity are the same ones for computing the bulk values. There is only one answer.
 

DonH56

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This is actually not exactly correct, there is only one physics, audio is just a limiting case. In fact if you model a cable with finite elements (R, L, C per unit length) you get exactly the same answer no matter how you look at it. The R, L, and C for the impedance and propagation velocity are the same ones for computing the bulk values. There is only one answer.

Yes, I need a better way to say it, and relate how impedance-matching, skin effect, and such is mostly irrelevant for consumer audio cables. My problem is that bulk or even distributed RLCG parameters (constant, linear) are insufficient to characterize propagation characteristics at "high" RF frequencies. And break down as you add non-TEM modes. Which I know you know; I was trying to simplify it...
 

scott wurcer

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Yes, I need a better way to say it, and relate how impedance-matching, skin effect, and such is mostly irrelevant for consumer audio cables. My problem is that bulk or even distributed RLCG parameters (constant, linear) are insufficient to characterize propagation characteristics at "high" RF frequencies. And break down as you add non-TEM modes. Which I know you know; I was trying to simplify it...

Of course, it's just the reaction you get when you tell someone the propagation velocity and impedance from a manufacture's data sheet gives the same answer for the bulk L and C. I suggest the OP spend a little time at http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
 

tomtoo

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Thank you for the replies gentlemen, I now have a few papers to read, names to look up, a few new terms to understand.

I am in no hurry to do so, this is just a hobby to me.

My experience with interconnect cables and speaker wires tells me there is an audible difference between designs/materials, but I don't know why.

If you use a turntable than maybe yes. The Phono preamps in mixture with cartridge and cable impedance could imo have some listenable effect.
At least thats what i can imagine.
 

Hayabusa

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  • The caveat to all of this is that skin effect applies only at radio frequencies of 1MHz and higher. If you look at the spec sheets provided by Mogami, Belden and Canare, you'll see that they categorize their products based on their use, and the graphs they provide don't provide much of anything for audio frequencies of 20Hz—20kHz, where not much matters when using simple wire, but go into much greater detail for products meant specifically for RF or digital signals.

Skin effect in copper at 20KHz is around 0.5mm, so solid copper wires will show some resistance change at higher audio frequencies depending on diameter and length.
But I agree that these effects are very minor... But its not true that the skin effect is for f>1Mhz only, even for power lines at 60Hz they take note of the skin effect for very thick solid copper wires...
 

DonH56

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Skin effect in copper at 20KHz is around 0.5mm, so solid copper wires will show some resistance change at higher audio frequencies depending on diameter and length.
But I agree that these effects are very minor... But its not true that the skin effect is for f>1Mhz only, even for power lines at 60Hz they take note of the skin effect for very thick solid copper wires...

Agreed; skin effect is significant at 20 kHz in the sense that the penetration depth of a 12 AWG wire is such that only about 30% or so of the diameter is used (see thread previously linked for a plot). That is usually more than enough area given the relatively low power and reduced sensitivity we have to 20 kHz signals. But like so many things, the reality of its impact and the marketing of its impact are often miles apart.

Transmission line effects very much apply to 50/60 Hz power lines since they are miles long (and carry a lot of current). Those little coils of wire around the wires overhead that you sometimes see are actually to improve their transmission characteristics. And as Scott would correct me, they always apply, just are not really relevant in home audio systems for the audio signals. They do matter for digital signals like HDMI, however.
 
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kach22i

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Generally because of sighted listening. Unless something is broken or seriously badly designed (e.g., thin speaker wires), ears-only evaluation shows that there’s no audible differences. The entire high end cable industry is built on quackery.
Those studies didn't include my wife.

I could not sneak new speaker wire or interconnect cable into my system without her asking "how much did you spend now?".

I mean she could hear the difference outside the room and just passing by.

I got busted every time.
 
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