The Science of Cables

We’re on it !

And speaking of nonsense, when you gonna be calling NASA ? I mean they have apparently really dropped the ball on dark matter and only have a black box understanding of it. Though that being said science has for centuries also dropped the ball on gravity and all it has to show for our understanding of that fundamental thingee is another black box understanding.  

@taras22

Produce an explanatory model and exemplar cables based on any of what you have written and then you'll have something to write about.

I am confused....There are plenty of folks on these these forums that are VERY knowledgeable about electronics, electricity, and circuits. There is an extremely wide price between the "junk" cables that came with a product and the super, extremely expensive ones that can be had.

I ask this question......how sophisticated must a system be to truly hear the difference in sound from a modestly priced cable and the super expensive ones? Is it just a matter of money?

@cheeg and @boxer12

Thanks for your kind words....very happy you found those bits a worthwhile read.

And speaking of nonsense here is something that is also interesting....this from a bunch of rocket science type guys....

Just thinking out loud here but wouldn't it be nice if someone who knows better give these guys a call and maybe straighten them out before they make even bigger fools of themselves.

https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy

Dark Energy, Dark Matter

In the early 1990s, one thing was fairly certain about the expansion of the universe. It might have enough energy density to stop its expansion and recollapse, it might have so little energy density that it would never stop expanding, but gravity was certain to slow the expansion as time went on. Granted, the slowing had not been observed, but, theoretically, the universe had to slow. The universe is full of matter and the attractive force of gravity pulls all matter together. Then came 1998 and the Hubble Space Telescope (HST) observations of very distant supernovae that showed that, a long time ago, the universe was actually expanding more slowly than it is today. So the expansion of the universe has not been slowing due to gravity, as everyone thought, it has been accelerating. No one expected this, no one knew how to explain it. But something was causing it.

Eventually theorists came up with three sorts of explanations. Maybe it was a result of a long-discarded version of Einstein’s theory of gravity, one that contained what was called a "cosmological constant." Maybe there was some strange kind of energy-fluid that filled space. Maybe there is something wrong with Einstein’s theory of gravity and a new theory could include some kind of field that creates this cosmic acceleration. Theorists still don’t know what the correct explanation is, but they have given the solution a name. It is called dark energy.

What Is Dark Energy?

More is unknown than is known. We know how much dark energy there is because we know how it affects the universe’s expansion. Other than that, it is a complete mystery. But it is an important mystery. It turns out that roughly 68% of the universe is dark energy. Dark matter makes up about 27%. The rest - everything on Earth, everything ever observed with all of our instruments, all normal matter - adds up to less than 5% of the universe. Come to think of it, maybe it shouldn’t be called "normal" matter at all, since it is such a small fraction of the universe.

Seriously tarras22, thank you for including that information here. Very interesting. 

+1 cleeds

So I can safely assume you are saying ixnay to a teaching career.

Darn, I’m crushed... I was so looking forward to it.

What @taras22 has posted reminds me of the dark energy and cold fusion "white papers" I have seen, which of course always turn out to be nonsense.

A survey of a lot of different areas of physics, devoid of any practical ability to use them. That is, for all that writing you have no model which suggests cable construction, measurements or expected results when implemented. It's just a verbose knitting together of irrelevant subject matter.

I'm not saying cables don't matter. I am saying that they can be explained by far simpler models, IF they work.

Given the cheapness of equipment which can measure at 36 bits and 96kHz or better, and cheapness of storage, you'd think a cable manufacturer would have produced hard core proof signals were altered at the end points, and have charts of measurements of it to explain what's happening. We don't. We have wildly different models and stories, from skin effect to you name it.

What little I have heard in cables, it wasn't worth a lot of money, and in my mind easily explained with simple answers.

Did you buy your other components based on measurements?  Tubes will measure different than solid state in some areas.  But some prefer tubes and others solid state.  Happy Listening.

There’s nothing I’ve ever heard in a cable that could not be explained by simple AC circuit analysis, and assuming amplifiers had more output impedance than claimed.

Nothing.

Best,

E

@tarras22 — thanks for the mini lecture! Best discussion I’ve heard on why cables matter. Have you considered teaching?

@BSMG, 
THAT DESCRIPTION OF EARS AND HEARING DIFFERENCE WAS TOO FUNNY. 

“Because if everything was spelled out to the uniformed these cables couldn't be sold with over the top prices . Have to keep the uniformed in the dark to be able to charge the ripoff prices.”

What if the secret to cables is that there is no secret. It’s just gauge, material and geometry and anyone can make a “world class” cable at home. Maybe that’s why cable manufacturer’s don’t give us every last spec. Ha!

“Own a hifi and you are required to be part of the customer base for cables.”

Yes, but if one fails to realize that the quality of the cables matter, or refuses to believe it, they might use the free cables that came with their equipment the entire time and never really hear what their system is capable of. There’s nothing wrong with that, but it doesn’t help increase the cable market, and a bigger market means more competition, better designs, more discovery and better cables for everyone (who chooses the buy them.)

I majored in physics.

Actually I have a Ph.D in Biophysics from UC. Berkeley.

But I do not believe in measurement in audio.

0.5 % Thd tube amplifiers tend to sound much better than .001 Thd SS amplifiers.

Cable making is a mixture of science and art.

I am impressed with Teo Cable in definition and clean decay although it falls slightly short of detail compared with silver or silver plated cables,


I am not sure whether liquid metal play lot of role or not.

You have to depend on your ears rather than numbers.

So as we can see from the above building cable is a piece of cake, like as been mentioned here by experts of every stripe all the laws governing cable building have been absolutely defined years ago ( well apart from that weird niggling quantum stuff and various inter-relational complexities ).

Why would measurements increase the customer base? If one owns a hi fi system isn’t speaker cable required for every channel of amplification, want it or not? I would guess that every source and set of separates requires interconnects as well.

Own a hifi and you are required to be part of the customer base for cables.

Whoops, forgot this wee bit.

I would argue that on a slightly handwaving way, you can study "electricity" using classical physics. After all, much of it can be understood through Maxwell's equations. However, if you do this, you simply have to consider the charge densities, dielectric constant, magnetic permeabilities, et cetera as black boxes.

Quantum mechanics kicks in if you want to understand why a material is a conductor or an insulator. In solids, you can treat these questions through the study of electronic band structures, which relies heavily on Bloch's theorem and also on the Fermi-Dirac statistics. These are all elements from quantum mechanics. Therefore, if you want to understand how these charge densities behave on a microscopic level, you need QM. In typical systems, we can recover more empirical notions of of electricity such as Ohm's law from quantum treatments.

Now, if you really want to study how electromagnetic fields and electrons interact with each other (in detail), you will have to go further and you need to consider quantum electrodynamics (QED). This will give you the most detailed description of how photons and electrons interact. I would argue, however, that QED is often a bit of an overkill for condensed matter or atomic physics problems (not always, but often). Therefore you will find many "effective models", which can significantly simplify things.

Among these effective models, you have for example the Hubbard model, which includes interactions between electrons, without explicitly including the fact that these interactions are mediated via the electromagnetic field. You have a whole zoo of similar models, so I will not go into all of them. The main point is that they usually focus on the behaviour of the electrons and do not explicitly consider couplings to the electromagnetic field. There are, however, models which study the response of the material to the electromagnetic field. Usually this leads you to models which treat quasi-particles, such as plasmons, polarons, and polaritons. I am a bit out of my field of expertise here, but I believe that these can be used to derive the parameters that go into Maxwell's equations. Note, however, that these models are still not explicitly considering full-scale quantum electrodynamics.

As I get the feeling that you are also interested in the radiation side of the story, let me shift gears a little. Radiation actually is a very old problem in quantum physics. It lies at the basis of the probabilistic interpretation of the theory and motivated Heisenberg to develop his matrix mechanics. Light-matter interactions in that time were narrowly connected to atomic physics and spectroscopy, later molecular and nuclear physics joined in, covering a range from microwaves to gamma-rays in the electromagnetic spectrum. Now, if we really want to understand in depth how the electrons (or nucleons for nuclear physics) in these systems interact with electromagnetic fields, we must again divert to QED.

Nevertheless, also on the side of the electromagnetic field, there are effective models. These can be found, for example, in quantum optics. In these models, you typically make serious simplifications on the level of the "matter" and focus on the electromagnetic field. Typically, the interaction between light and matter generates some type on nonlinear effects in the electromagnetic field, so I would argue that the vast majority of models in nonlinear optics are models where you had some type of interaction with matter, which you coarse-grain out. Note, however, that these effective descriptions do not even require quantum mechanics to make sense. You can usually do nonlinear optics using Maxwell's equations. If you want to see effective models of the quantum side of the electromagnetic field in action, you have to turn to quantum optics, where you usually include matter (like a "two-level atom") in a more explicit way, see for example the Jaynes-Cummings model.

With this little excursion into the realm of optics, you may notice that there was not a lot of "electricity". The reason why we did not really get into that, is because it is horribly difficult. The treatment of models in condensed-matter theory, which only deal with the interacting electrons are complicated on their own and so is the theory of the quantum and nonlinear effects in the electromagnetic field. There is, however, one additional playground which we can explore. You may wonder what happens when we consider quantum properties of the electromagnetic field and combine them with macroscopic conductors and insulators. This is done in what is called Macroscopic quantum electrodynamics, which can be used to study for example the Casimir effect.

To conclude, let me stress that genuine quantum effects in the electromagnetic field itself (so everything related to light et cetera) are quite rare in day to day life. The electromagnetic radiation effects that are related to electronics and electricity is described really well by Maxwell's equations. However, if you really want to understand what happens in materials through which your electricity flows, on a microscopic level, you will have to consider the quantum models of condensed-matter physics.

Disclaimer: None of these fields is really my speciality, so I would be happy if a condensed-matter physicist or a quantum optician could provide more details or corrections if necessary.

A couple of things when considering the cable building thingee.

The LCR wire model is applicable only with air as a dielectric. Makes perfect sense in that application. Once that wire is encapsulated in varnish, enamel, lacquer or dielectrics of varying consists then all bets are off. “Wire” then becomes an electrical system that is very different from the raw metal.

And this from here....   https://positive-feedback.com/audio-discourse/rcl-part-2-roger-skoff-cables/

Let's see how. Let's start by simply accepting the engineers' favorite factors for cables: R (resistance), C (capacitance), and L (inductance). They say that those things make a difference, and it's true. Among other things, they can affect both the power level passed by a cable and its frequency response.

In thinking about this, remember a couple of things. First, that "resistance" is a term best applied to DC (direct current), and that with AC (alternating current) signals like music, wherever there is capacitive or inductive reactance (as there always is in cables), the more correct term to use is probably "impedance" (Z).

Second, remember that inductance, one of those favored factors, "…is the property of an electrical conductor by which a change in electric current through it induces an electromotive force (voltage) in the conductor." (read more HERE) What that means is that any current flowing through a conductor causes an electromagnetic field to form around that conductor (and out to infinity, in accordance with the "inverse-square law"), and that, when the direction of that current changes (as it does every time the AC current changes polarity) the field collapses and the collapsing field creates a voltage ("back EMF") that opposes the flow of incoming new signal. The higher the frequency, the more of an effect this has on the sound.

Remember, also, that capacitance, another of the "favored factors", is the ability to store energy (read more HERE), and that a capacitor is formed any time two conductors ("plates") are brought together, separated by a non-conductor "dielectric" (read more HERE). What that means is that every cable is, by definition, a capacitor, with its two conductors (positive and negative or "going" and "coming") being the plates, and the insulation between them being the dielectric.

Now, have you ever noticed that, when electronics designers or engineers call for a capacitor to be included in a circuit, they not only specify its capacitance, but also its type? (Ceramic, Film and paper, Polymer, air gap, mica, tantalum, and many, many others (read more HERE and HERE). If factors other than just the measured capacitance of a capacitor are important (and can make a performance difference) in other types of capacitors, how can those exact same things not make a difference in cables?

The amount of capacitance—and of inductance—in any cable or other capacitor is largely determined by how far apart the "plates" are spaced, with those two factors in a sort of "seesaw" balance:  The more capacitance there is, the less inductance, and vice versa.

Another very major factor is the material that the dielectric is made of:  For cables, virtually all of the various non-conductive elements are part of the dielectric. This is important in two ways: The first is that different dielectric materials have different dielectric constants (the ratio of the capacitance of a capacitor in which a particular insulating material is the dielectric, to its capacitance in which a vacuum is the dielectric, read more HERE). Or, to put it most simply,  the dielectric constant of a material is a number that shows how much energy any given volume of it  can store as compared to that same volume of vacuum. By way of illustration, the dielectric constant of a hard vacuum is 1.0, while balsa wood (a little stiff for most cables) is 1.4. Teflon® (there are several varieties) is around 2.0.  Polyethylene is around 2.2, and PVC and TPR (thermoplastic rubber), the two most popular cable insulators, by far, can have dielectric constants of as high as 6.8 (read more HERE).

Whatever the amount of stored energy, when the signal carried by the cable changes polarity, all of that energy is dumped into the signal path, canceling some of the incoming signal, or actually creating out-of-phase artifacts. This results in either the loss of low-level information or the actual creation of new information, either of which would be surprising if it didn't affect the sound!

The other important thing about dielectrics (which, remember, include the non-conducting elements of a cable) is their "dump rate"—how quickly they can release stored energy after the signal changes polarity so that they can start storing the new signal energy coming in. Dump rates vary wildly, with some materials, PVC, for example, being quite (relatively) slow and others (Teflon®, for example) being very, very fast. This can make a definitely audible difference (with faster dump rates that affect the incoming signal for less time being much preferred), and, surprisingly, the dump rate of a material and its dielectric constant are not directly proportional. Polyethylene is only around ten percent higher in dielectric constant than the best form of Teflon®, but has—while still vastly faster than PVC —an audibly slower dump rate, to lose low-level detail and "muddy" its sound.

There are still other factors that affect the sound of a cable—its "geometry"; the type, purity and crystal structure of the metal in its conductors:  the existence of mysterious (and perhaps mythical) micro-diodes at the crystal junctures of copper; the self- and mutual-inductance of both the cable and its connectors; how much and what kind of metal those connectors are made of, and many more, but I'm out of space for now.

@millercarbon claims:

Electrical measurements are totally irrelevant.

 
 Tell us you can’t hear the difference between a lousy Walmart 24 AWG “speaker” cable and a decent audiophile 12 AWG speaker cable, or a lousy 50 cent dollar store interconnect with 1000 pF per foot capacitance between your preamp and amp, compared to an audiophile cable with 12pF per foot capacitance? Or is it “all good” as long as you shake the magic chicken’s foot at it?

Because if everything was spelled out to the uniformed these cables couldn't be sold with over the top prices . Have to keep the uniformed in the dark to be able to charge the ripoff prices .

Ears remain the best test instrument and practically no ears are like any other ears. What I mean is that if your ears protrude further from the side of your head than normal you will hear totally differently than someone who has ears that remain close to their head. You can demonstrate this by physically moving your ears out while listening to music. The difference is dramatic.

measurements? how about only buying from companies that give you a trial period and get your ears measured and rely on them.

For all the objectivists who wail "all we need to know is L, C and R", I’ve yet to hear what those values are in any given system. There is no one size fits all solution.

All the best,
Nonoise

Physical measurements are great for determining how much voltage and current a line can safely carry, what insulation is required for what voltage, etc. That's it.

Audio is not about any of that. Audio is about how it sounds. Electrical measurements are totally irrelevant. Sorry, but they are. This is probably because of our present poor understanding of exactly what it is that makes something sound good.

Stop and actually think about this one for a minute. When we know how to make something, when the science is worked out fully, then everyone would know it. They would all be doing the same, or pretty much the same. Seen any airplanes with the flat part of the wing on top? Not likely! Because we understand the science and physics of air flow. 

But now notice, even in aircraft where we understand really well what is going on, hence all airplane wings look the same, this does not hold true at the sharp end of development. Stealth and hypersonic aircraft wings do look a little different. Because these delve into areas where we are still figuring out and trying to understand. Or they are special applications, with their own specialized performance criteria.

Still figuring out and trying to understand? Highly specialized performance criteria? That is the whole entire subject of high end audio! Nobody knows why one thing sounds better than another! Nobody! Hardly anyone even agrees on what better sound sounds like!

These are simply the facts. We don't agree if sealed, ported, transmission line, dipole, electrostatic, Bose or Wilson sounds better. We don't agree on gold, silver, rhodium, copper, or layers of some or all or mixes of unobtainium being best for wire. Or on the dielectric, or even, once we make the darn things, where they should go: On the floor? Or elevated above it??? You think anyone's gonna stand any chance using measurements or design to select speaker cable?
That's a good one. Tell me another one. I'm stuck in LA waiting for a flight. I could use a good laugh.

mkgus

I know several “objectivist” that won’t accept any of your claims unless you have measurements and blind tests ...

Who cares? Measurementalists are free to conduct their own tests.