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You left out topology--the physical design and / or weaving.

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In Reply to: RE: A Question for All... posted by thetubeguy1954 on July 31, 2022 at 21:34:59

Lamp cord has the hot and cold wires in parallel. In that scenario, the electromagnetic flux behaves in certain ways, some of which are generally regarded as bad. E.g., the electromagnetic flux going down the hot (+) wire to the load induces a current in the cold wire.

That is why the first Transatlantic telegraph cables (before Lincoln was President) were terribly slow and inefficient. The electromagnetic flux going down the wire induced a current at right angles, and when that current hit the surrounding water, it made a right turn, so there was an induced current in the opposite direction dragging the signal's speed down.

Queen Victoria's message to President Buchanan was something like 92 words, but it to something like 8 hours to send.

Self-taught math genius Oliver Heaviside (Wiki him!), a UK Post Office employee, by the use of math alone, in 1880 designed the first true coaxial transatlantic cable.

However, for various reasons, most speaker cable designs these days are not simple 1880-style coaxial cables. Nordost's entry-level cables, for instance, attempt to solve the self-inductance problem in a different way. Whereas Cardas' very complex Clear speaker cables are essentially (IMHO) an elaboration on the idea of the coaxial cable.

Cardas also takes into account the mechanical motion induced in the wires by the transit of the electromagnetic flux going down the wire.

So, in conclusion, there are no "best" answers in a vaccuum each by itself. A modern loudspeaker cable is a complex system, and the case with most complex systems is, "In order to get more of this, I have to give up some of that," even if the only thing being sacrificed is affordability.

I have designed S/PDIF and Word Clock cables and AES digital cables and also electric guitar cables, but speaker cables present complexities orders of magnitude greater than those cables. IMHO.

amb,

john
https://en.wikipedia.org/wiki/Oliver_Heaviside (Open in New Window)

Follow Ups:

RE: You left out topology--the physical design and / or weaving. - geoffkait 14:54:23 09/29/22 (0)
In lamp cord there isn't a hot and cold wire running in parallel. The current (actually electrons) runs on both wires, that's how AC works. What Heaviside was describing is the "energy flux density" not electromagnetic flux. The so-called "Poynting vector" points in direction of electron motion. Electric fields and magnetic fields alternate E, B, E, B, etc. along both wires constantly, the directions opposite each other and alternating. The energy of the signal is contained in the E and B fields, which lie outside the metal conductors, the units of Poynting vector are Watts per meter squared.
Current actually doesn't flow along wires, current is a calculated quantity that has no velocity or direction. It's a scalar quantity. The current is calculated by adding up all the moving free electrons for the cross-section of the conductor. Thus thicker conductors support higher currents. The only thing actually moving is electrons, and they don't move fat or far. One meter per hour and about a millionth of an inch at one time (half cycle) depending on instantaneous audio frequency in speaker cables. Does that surprise you? For power cords the electrons would travel a little farther each half cycle since the rate of alternation 60 Hz is slower than for speaker cables.
The direction of electric and magnetic fields are perpendicular to each other and to direction of electron flow. The magnetic field B is induced by moving charges (I.e., free electrons) and the electric field is induced by the voltage.
The difference between power cords and speaker cables is basically that rate of alternation, 60 times per second for power cord and whatever the instantaneous audio frequency is, nominal 20-20k times per second (Hertz) for speaker cables.

Edits: 09/29/22 09/29/22 09/29/22
RE: You left out topology--the physical design and / or weaving. - 6bq5 12:16:49 08/01/22 (2)
John,
If I read your post correctly are you suggesting a Coaxial cable at a larger scale - say ~2" or larger in diameter so that the B fields interference is lessened?
Happy Listening
- No no no no no - John Marks 14:51:54 08/01/22 (1)
  I don't feel I have anything to offer, at least at this time, in loudspeaker cable design. Whereas I do think I have something to offer in digital cables.
  
  There's a lot more going on inside Cardas Clear than in a classic co-axial conductor-and-shield cable.
  
  I have no idea whether a classic co-axial conductor-and-shield loudspeaker cable would work, but I see at least two deal-breakers: 1) Skin effect on the core conductor; and 2) the cable would end up having very inconsistent physical and electrical resonances--centered around one "tuning point."
  
  That's fine if you know that the only signal you are dealing with is digital pulses at 44.1kHz; but not so good for analog music.
  
  ciao,
  
  john
  - RE: No no no no no - 6bq5 14:59:46 08/01/22 (0)
    Thanks-
    I have always been a bit skeptical of wire claims for Mains power -
    Speaker wire - while conducting AC, it is at low voltage and amperage- and should be well served by separate wires reasonable spaced
    Analogue interconnects - I learned a lot when making equipment for Music Reference and Audible Illusions-
    Digital - not my realm.
    Happy Listening

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