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
Coincidentally there is a recent review in audio science review in which RCA cables from three distributors, with fairly wide price differences, are compared from both a performance and an auditory perspective. No significant differences were found

https://secure.aes.org/forum/pubs/journal/?ID=979


That's funny AES did a study and found the opposite. I would trust AES over ASR any day of the week.



The AES paper doesn't tell you anything other than RCA and XLR, unbalanced and balanced can sound different. It didn't compare apples to apples. 

The square wave and sine wave are not the same thing the square wave simulates all audio frequencies and MORE, the and more is infinite bandwidth. The test shown in that video is not band limited to audio frequencies  The refections shown are above 50kHz. 
Coincidentally there is a recent review in audio science review in which RCA cables from three distributors, with fairly wide price differences, are compared from both a performance and an auditory perspective. No significant differences were found

What a surprise. ASR is deeply conflicted, and tragically misinformed. Just look at this: 
compared from both a performance and an auditory perspective

What do they mean, "both"? The whole purpose of high end audio is sound quality. The "auditory perspective" IS the only "performance" that matters. How it sounds is how it performs. They are one and the same. The whole point of high end audio is to reproduce the sound of music. Of this they are utterly oblivious. Deep, tragic confusion. Epic. Anyone wants to know exactly how NOT to get good sound, study ASR. The Gold Standard of ineptitude.
Most people think the sound come FROM their beloved chosen  gear...

When they dont like the sound they replace the gear and called that an upgrade...

Some measure the gear and call that "science", anything not measurable is "magic"...

These two different kind of people are deluded, some buy cables to upgrade and others bash them....There is no deep difference here ,they own their own blinders anyway and exist like foe exist for the sake and by the virtual existence of the other neighbouring foe....




I am afraid the truth is too complex for simple mind and too simple for complicated unclear mind :

The sound we listen to come MOSTLY from speakers/room/ears interaction...Not FROM the gear directly even if the gear play his own impact on the sound quality....

How do you measure that?

No way....

It is a dynamical CIRCUIT in hundredth of seconds between the speakers--->the room-->`the ears--> add a change here in the room treatment or a new Helmholtz resonator for example and listen another time... It is a listening experiment in a CYCLE of experiments.....Even a single straw at the right place with the right diameter may have an effect comparable to an upgrade....

Because a tone is NOT a playing note or chord, nor the timbre could be reduced to a spectrum, you cannot replace ears with a measuring apparatus....And you cannot replace acoustic laws and psycho-acoustic laws with a piece of new gear or a new cable to reach High quality sound....

Is it not simple to understand?


Coincidentally there is a recent review in audio science review in which RCA cables from three distributors, with fairly wide price differences, are compared from both a performance and an auditory perspective. No significant differences were found

https://secure.aes.org/forum/pubs/journal/?ID=979


That's funny AES did a study and found the opposite. I would trust AES over ASR any day of the week.


Do you have link to ^that^ AES study?