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Directionality of wire

I am a fan of Chris Sommovigo's Black Cat and Airwave interconnects. I hope he does not mind me quoting him or naming him on this subject, but Chris does not mark directionality of his IC's. I recently wrote him on the subject and he responded that absent shunting off to ground/dialectric designs, the idea of wire directionality is a complete myth. Same with resistors and fuses. My hunch is that 95% of IC "manufacturers", particularly the one man operations of under $500 IC's mark directionality because they think it lends the appearance of technical sophistication and legitimacy. But even among the "big boys", the myth gets thrown around like so much accepted common knowledge. Thoughts? Someone care to educate me on how a simple IC or PC or speaker cable or fuse without a special shunting scheme can possibly have directionality? It was this comment by Stephen Mejias (then of Audioquest and in the context of Herb Reichert's review of the AQ Niagra 1000) that prompts my question;

Thank you for the excellent question. AudioQuest provided an NRG-10 AC cable for the evaluation. Like all AudioQuest cables, our AC cables use solid conductors that are carefully controlled for low-noise directionality. We see this as a benefit for all applications -- one that becomes especially important when discussing our Niagara units. Because our AC cables use conductors that have been properly controlled for low-noise directionality, they complement the Niagara System’s patented Ground-Noise Dissipation Technology. Other AC cables would work, but may or may not allow the Niagara to reach its full potential. If you'd like more information on our use of directionality to minimize the harmful effects of high-frequency noise, please visit http://www.audioquest.com/directionality-its-all-about-noise/ or the Niagara 1000's owner's manual (available on our website).

Thanks again.

Stephen Mejias
AudioQuest


Read more at https://www.stereophile.com/content/gramophone-dreams-15-audioquest-niagara-1000-hifiman-he1000-v2-p...


fsonicsmith

Showing 6 responses by sfroyen

sfroyen
7 posts
 
You can easily roll your own directional speaker cables. Just add two diodes to each cable -- one diode in series with each of the two wires. For the ultimate effect, orient them in the same direction (say, with the arrows pointing away from the amp), or, for a more interesting effect, place them in opposite direction.

From this simple test, i think you will conclude that directional cables is NOT what want in your system.
sfroyen
7 posts
 
Manufacturers of "directional" cables argue that it is the direction of the energy flow that is important (from wall to power amp, from power amp to speakers etc). This way they can market their AC power cables, speaker cables etc. They conveniently ignore the fact that the energy flow takes place in the dielectric surrounding the conductors -- including the surrounding air. Any asymmetry in the crystal structure of the conductors themselves would only impact electron motion and would likely result in undesirable diode behavior.
sfroyen
7 posts
 
Assuming you are serious :-)

I'm distinguishing between the electron motion, which, of course happens inside the conductor, and the flow of energy that powers, e.g., the speakers. The latter is carried by the electromagnetic field that is generated by the electron motion, but is located outside the conductors. This follows from Maxwell's equations which are valid from DC to any frequency of relevance to EE and breaks down only when describing certain quantum effects (see QED).
sfroyen
7 posts
 
geoffkait

There is no law saying photons can't travel in copper. In fact it's the physical non symmetry of the copper ITSELF that gives rise to directionality. Hel-loo!

>>>>>Indeed there is. The laws are called Maxwell's equations and were published in the 1860s. They are fully relativistic and form the basis for all electric, optical and radio technologies. In fact they are also used to calculate the skin-effect. As I stated above, any asymmetry in the copper can only affect the electron motion -- not the photons (electromagnetic fields and photons are one and the same).
sfroyen
7 posts
 
If somebody is interested in the math of electrical energy flow in cables, this is a good article in Am. J. Phys. (it's possible to read the paper without following all the math):

http://depa.fquim.unam.mx/amyd/archivero/El_flujo_de_energia_de_una_bateria_a_otros_elementos_de_un_... 
sfroyen
7 posts
 
geoffkait:
It is illogical to say that "electricity" or current or voltage is an electromagnetic wave ...

>>>>While you may think it's illogical, electrical energy transfer still happens through the electromagnetic field. The paper I referred to earlier shows how this works for DC. The energy flows in the direction of the Poynting vector. For a zero resistance cable, this vector is zero inside the cable (there is no electric field), and it is oriented parallel to cable outside the cable. For a non-ideal cable the Poynting vector has a small component directed  perpendicular to cable, transferring energy into the cable, causing ohmic heating.

geoffkait:
The reason why the audio signal travels at say, 70% the speed of light in a copper conductor is because the audio signal is traveling through copper.

>>>>This is patently untrue. The propagation speed is limited by the dielectric constant of the material surrounding the conductor. Look up, e.g., propagation speeds for coaxial cables.

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