Interconnects, some have directional indicators, why?


I'm curious as to why some interconnects are directional? Is there a physical internal difference and do they generally sound better and cost more than non-directional cables? Thanks for your interest.
phd
Current in the wire is a flow of electric charge. Wire creates magnetic field but transports charges and not the energy. Energy is transferred thru magnetic field from the source to the load.
The load has some voltage drop in it, hence electric field. Together with magnetic field, this brings the energy in. Same way, the source generates voltage and, together with magnetic field, this brings the energy out.
Direction of electromagnetic energy flow is determined by the Poynting vector, E × H, and depends on both voltage polarity (through E) and current direction (through H).
As I understand it, even in DC circuit energy flows from source to load thru the space in direction of Poynting Vector.

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Can anyone please show the result of a scientifically performed double blind test using, let's say, 10 different manufacturers brand new 4' cables connected in the two different directions but otherwise identical and a panel of 10 listeners?

Then the cables should be "burnt-in" for a period of one month. the test repeated and then reversed and "burnt-in" again for the same period and a third test performed using the same identical set-up.

If the result is 2/3-1/3 or more in favor of one direction it would be a statistically significantly proven fact that inherent cable directionality is indeed relevant…

Personally I have never noticed any difference when turning a symmetrically terminated interconnect cable around but that is of course no proof that directionality do not indeed exist in some cases.

The current flow in unbalanced IC's is negligible. Input impedances are in the order of 5-100Kohms so it's basically only voltage changes that are relevant. Speaker cables are a different thing. When powering speakers current is the major factor (except for electrostatic loudspeakers).

Maxwells equations are of course still relevant in IC's but I must say that some people do make some very uneducated scientific remarks in this discussion.

There are basically the following factors:
1. Voltage
2. Current
3. Resistance
4. Capacitance
5. Inductance
6. Impurities in the material
7. Self induction

Factors that are all statistically the same for the whole length of a cable so where does inherent directionality fit in?

I'm not saying that inherent directionality does not exist but until someone presents a double blind test along the lines of the test suggested above I'm very sceptical about it's existence since it does not make any sense at all theoretically. Even if you turn the cable around the strands are still twisted the same way and every other factor also remains the same.

Could it be that the extrusion process would impart an inherit direction? Not very likely since atoms are 100% symmetrical and identical and all impurities in the material are distributed completely at random. The whole concept of inherent directionality in cables just does not make any sense to me as a scientist and if it really does exist it must be possible to scientifically explain the reasons for it.

Can someone please do THAT? Not just present a lot of hocus-pocus statements that have no scientific relevance at all...


kraftsound wrote,

"I’m not saying that inherent directionality does not exist but until someone presents a double blind test along the lines of the test suggested above I’m very sceptical about it’s existence since it does not make any sense at all theoretically. Even if you turn the cable around the strands are still twisted the same way and every other factor also remains the same."

A double blind test is just one data point. so if the results are negative one cannot make generalities regarding directionality, i.e. wires or fuses are not directional. there are many reasons why a double blind test might fail, just like any test: e.g., operator error, system has at least one error preventling full resolution.

"Could it be that the extrusion process would impart an inherit direction? Not very likely since atoms are 100% symmetrical and identical and all impurities in the material are distributed completely at random. The whole concept of inherent directionality in cables just does not make any sense to me as a scientist and if it really does exist it must be possible to scientifically explain the reasons for it.

Can someone please do THAT? Not just present a lot of hocus-pocus statements that have no scientific relevance at all..."

The metal conductors are crystal structures, they are not amorphous. Atoms are arranged in crystal lattices, which are unique for each metal. All metals are crystals. directionality is produced by distortion of the original symmetrical crystal structure that exists after the molten metal is poured. hammering, rolling, drawing, bending - they all distort/deform the crystal structure. Drawing the wire through a die deforms the crystal structure such that the wire is made unsymmetrical and non-homogeneous, like the quills on a porcupine’s back. So, wire is INHERENTLY directional.

You can ignore impurities in the wire since we’re talking about metals that are 99.999999% pure in the case of copper.

Does that make any sense to you as a scientist?


Geoff, above and in many discussions you have stated that the wire drawing process impacts the wire crystal structure making it inherently directional.

Assuming it does, I think the question is does this impacted crystal structure in some way make an audible sound difference when the wire is inserted into a system in one direction or the other?

One might think that in order for it to make a difference, the signal, power, whatever, would need to flow differently depending on the direction of the crystal structure.  This would imply that if the wire was inserted incorrectly from a directionality viewpoint, the crystals are impeding, or in my obviously non scientific terms ,snagging and impeding the signal or power compared to the correct direction and this somehow impacts the sound. 

George