Science that explains why we hear differences in cables?


Here are some excerpts from a review of the Silversmith Audio Fidelium speaker cables by Greg Weaver at Enjoy The Music.com. Jeff Smith is their designer. I have not heard these cables, so I don’t have any relevant opinion on their merit. What I find very interesting is the discussion of the scientific model widely used to design cables, and why it may not be adequate to explain what we hear. Yes it’s long, so, to cut to the chase, I pulled out the key paragraph at the top:


“He points out that the waveguide physics model explains very nicely why interconnect, loudspeaker, digital, and power cables do affect sound quality. And further, it can also be used to describe and understand other sonic cable mysteries, like why cables can sound distinctly different after they have been cryogenically treated, or when they are raised off the floor and carpet.”


“One of the first things that stand out in conversation with Jeff about his cables is that he eschews the standard inductance/capacitance/resistance/impedance dance and talks about wave propagation; his designs are based solely upon the physics model of electricity as electromagnetic wave energy instead of electron flow.


While Jeff modestly suggests that he is one of only "a few" cable designers to base his designs upon the physics model of electricity as electromagnetic wave energy instead of the movement, or "flow," of electrons, I can tell you that he is the only one I’ve spoken with in my over four decades exploring audio cables and their design to even mention, let alone champion, this philosophy.


Cable manufacturers tend to focus on what Jeff sees as the more simplified engineering concepts of electron flow, impedance matching, and optimizing inductance and capacitance. By manipulating their physical geometry to control LCR (inductance, capacitance, and resistance) values, they try to achieve what they believe to be the most ideal relationship between those parameters and, therefore, deliver an optimized electron flow. Jeff goes as far as to state that, within the realm of normal cable design, the LRC characteristics of cables will not have any effect on the frequency response.


As this is the very argument that all the cable flat-Earther’s out there use to support their contention that cables can’t possibly affect the sound, it seriously complicates things, almost to the point of impossibility, when trying to explain how and why interconnect, speaker, digital, and power cables have a demonstrably audible effect on a systems resultant sonic tapestry.


He points out that the waveguide physics model explains very nicely why interconnect, loudspeaker, digital, and power cables do affect sound quality. And further, it can also be used to describe and understand other sonic cable mysteries, like why cables can sound distinctly different after they have been cryogenically treated, or when they are raised off the floor and carpet.


As such, his design goal is to control the interaction between the electromagnetic wave and the conductor, effectively minimizing the phase errors caused by that interaction. Jeff states that physics says that the larger the conductor, the greater the phase error, and that error increases as both the number of conductors increase (assuming the same conductor size), and as the radial speed of the electromagnetic wave within the conductor decreases. Following this theory, the optimum cable would have the smallest or thinnest conductors possible, as a single, solid core conductor per polarity, and should be made of metal with the fastest waveform transmission speed possible.


Jeff stresses that it is not important to understand the math so much as it is to understand the concept of electrical energy flow that the math describes. The energy flow in cables is not electrons through the wire, regardless of the more common analogy of water coursing through a pipe. Instead, the energy is transmitted in the dielectric material (air, Teflon, etc.) between the positive and negative conductors as electromagnetic energy, with the wires acting as waveguides. The math shows that it is the dielectric material that determines the speed of that transmission, so the better the dielectric, the closer the transmission speed is to the speed of light.


Though electromagnetic energy also penetrates into and through the metal conductor material, the radial penetration speed is not a high percentage of the speed of light. Rather, it only ranges from about 3 to 60 meters per second over the frequency range of human hearing. That is exceptionally slow!


Jeff adds, "That secondary energy wave is now an error, or memory, wave. The thicker the conductor, the higher the error, as it takes longer for the energy to penetrate. We interpret (hear) the contribution of this error wave (now combined with the original signal) as more bloated and boomy bass, bright and harsh treble, with the loss of dynamics, poor imaging and soundstage, and a lack of transparency and detail.


Perhaps a useful analogy is a listening room with hard, reflective walls, ceilings, and floors and no acoustic treatment. While we hear the primary sound directly from the speakers, we also hear the reflected sound that bounces off all the hard room surfaces before it arrives at our ears. That second soundwave confuses our brains and degrades the overall sound quality, yielding harsh treble and boomy bass, especially if you’re near a wall.


That secondary or error signal produced by the cable (basically) has the same effect. Any thick metal in the chain, including transformers, most binding posts, RCA / XLR connectors, sockets, wire wound inductors, etc., will magnify these errors. However, as a conductor gets smaller, the penetration time decreases, as does the degree of phase error. The logic behind a ribbon or foil conductor is that it is so thin that the penetration time is greatly reduced, yet it also maintains a large enough overall gauge to keep resistance low.”


For those interested, here is more info from the Silversmith site, with links to a highly technical explanation of the waveguide model and it’s relevance to audio cables:


https://silversmithaudio.com/cable-theory/


tommylion
Clearthinker, I think you are being a bit too harsh on the
englishman-in-newyork. He is just making generalizations that are more true about the individuals in this group than other groups excepting mahgister because I am not quite sure which group he fits into.

englishman-in-newyork, I am a doctor who has a science centered education. I make furniture and subwoofers. I started building Dynakit amplifiers when I was 13 and in high school constructed the power supply racks for dbx 32 channel noise reduction systems.(child labor) I am 67

I can still hear to 16 kHz and do not yet have tinnitus. I use 8 foot electrostatic loudspeakers. I am of course totally anecdotal. 

Excepting the population dynamics I agree with everything you say. If you want to know why these silly trends get started I politely suggest that you might want to study articles on psycho-acoustics, the way we interpret what we hear. There are solid reasons why these people believe what they hear is true even though it is just an illusion. Magicians do this in a visual manner. 
@tommylion     

First, thanks for the attempt to inform our readers about something they may find interesting.    
Second, I admire the bravery you showed in waving your red cape in front of some of the angry bulls that populate this site.    

I am always amazed at how so many amateurs believe they know more about a subject than people with actual knowledge and training, And why some people's first reaction to a different idea is to dismiss it out of hand, without even the courtesy of a valid counter argument.    

Don't get me wrong, I have no idea if Jeff Smith is 100% correct in his assertions, but I am honest enough in my limited knowledge to not argue his point. After all, Jim Smith's theory may turn out to be the audio equivalent of the "Fosbury Flop".

To those who don't believe cables make a difference, I often wonder at what point they would hear a difference. Would they think a solid piece of coat wire sounds as good as the Silversmith? 
I often hear that any competently-engineered wire will sound as good as something else. Well, what exactly does competently-engineered mean? Does the lamp cord from Home Depot meet that criteria?

As far as measurements, the differences in capacitance alone between different makes should be enough to understand how sound may change, but to the none believers this seems mute. 

Furthermore, I have yet to see a measurement that explains how I can detect a vocal passage in a complicated song mix better through one cable, but not another. That kind of measurement still does not exist. For those believing otherwise, you sound like a 16th century alchemist who says that all science and knowledge is already uncovered.



Just like those super expensive speaker makers, none of them has the courage to go through blind tests.
Clearthinker, I think you are being a bit too harsh on the
englishman-in-newyork. He is just making generalizations that are more true about the individuals in this group than other groups excepting mahgister because I am not quite sure which group he fits into.
If someone insult all a group of people indiscriminately for example : "audiophiles", it is truly wrong, and not very subtle...

The reason is simple, nobody can describe this group, composed of too many people with complex experience and history, including musicians and even many engineers....Then insulting all an indefinite group speak more about who is the personn throwing insults than about those who are insulted...








Most people audiophiles or not, think that we listen to the sound coming from the audio system...Then they point to the importance of electronic design...It is not wrong at all for sure.... It is a half truth though, it miss the other part of reality: embeddings controls and acoustic especially....


Secondly, you are right about me....

I am an audiophile because of my listening experiments, but i am  first a music lover and i think the opposite of the majority of audiophiles:

I listen the sound coming from my speakers/room/ears mainly....Not from the gear mainly....

This explain my position concerning the useless obsession to upgrade BEFORE embedding rightfully in their working dimensions, mechanically, electrically ands especially ACOUSTICALLY all the electronic designed pieces of gear....The urge to upgrade is re-inforced by marketing method from the engineering perspective in the audio community...

The basic history of electronic design is mature for the last 50 years... It is then easy to buy a good piece of electronic design at low cost...Out of the new hype ....




Myself I think against the "objectivist" and the kind of people who vouch ONLY for measurements like the anti-audiophiles that room/ears/speakers acoustic and psycho-acoustic science and ART are more important than electronical measurements of the gear to reach S.Q. nowadays... We are no more at the Marconi era...


For example room microphone connected to an electronical equalizer measurement are a secondary tool only an help, not the  ONLY way to tune and fine tune a room for  the speakers AND our ears  at all...

That is my experience, not an opinion of an audiophile or the dogma of a non audiophile...

My experience is not based on soldering or computer driven dials evaluation, but on listening experiments then on acoustic art and Helmholtz mechanical method...

I dont reject measurements, but some of the uses which are promoted in some circle about what is audio and musical experience...

I dont reject the necessity and the importance of a very good piece of electrinical engineering design, i only say that nowadays it is easier to purchase one than to LEARN how to LISTEN acoustically speaking and also musically speaking...









In one scientific word: Timbre is not spectrum....Physical acoustic science is not psycho-acoustic scence...our ears are the missing and always present  link between these 2 in audiophile experience...


Or in brief:

I always listen WITH my system or any other one , THROUGH the controlled and mechanically and psycho-activated room/speakers, i listen to the the "RECREATED  acoustic translation" of a past lived event recorded and  which become always an ACTUAL "different" acoustical event in my room or in any room anyway ...


Most people think the opposite:

They think they listen WITH their uncontrolled and passive room/speakers ,THROUGH their system the "magical" electronical "REPRODUCTION" of a lived PAST event, identical or almost to the original lived event....Because they imagine the recording microphones naively like a true memory not like a string of choices and TRADE-OFF which will modify the original performance anyway....