2. cables
  3. 1417566123

Directional speaker cables - switching direction

Some time ago I started a thread regarding speaker wire directionality and my inability to understand how it could have any affect on sound quality. The question was inspired by the fact that, after quite a few years using them with my Martin Logan Odysseys, I discovered that the cables (Straightwire Octave 2) had arrows printed on them. Not surprisingly the opinions expressed were pretty strong on both sides of the argument but those supporting directionality were the most vociferous and in greater numbers, one to the point of being downright insulting. In no case, though, was an explanation given by those supporting the importance of cable direction for how this phenomenon occurs except that it should be obvious that when a cable is broken in in one direction only someone with an uneducated ear would be unable to discern the difference.

Even though I still don't get it I'm not taking the position that there is no validity to the directional claim; if there truly is I just don't understand how. This leads me to my two part question. I haven't been using the Octaves for a few years but now, because of cable length issues, I want to put them back in my system partly to avoid the cost of new quality cables.

IF, then, the directionality theory IS valid and I don't recall which way the arrows originally pointed or which direction they were "broken in" do those in support of directionality think I should install them with the arrows pointing toward the speakers
broadstone

Showing 10 responses by kijanki

kijanki's avatar
kijanki
4,452 posts
 
Many believe that direction should not matter since we're dealing with AC current (charge flows in both directions). It might be a little bit more complicated than that, since energy is delivered only in one direction by the electromagnetic field on the outside of the cable (Poynting Field). I just don't know enough to question sanity or honesty of cable designer while I don't see any reason not to use it in recommended direction.
kijanki's avatar
kijanki
4,452 posts
 
But power is delivered only one direction thru electromagnetic field. Who said anything about displacement of electrons?
kijanki's avatar
kijanki
4,452 posts
 
So if energy flows in one direction, which direction
does it flow?
+ to - or - to + ?

From source to load independently of polarity.
kijanki's avatar
kijanki
4,452 posts
 
Jea48, I don't know if conductor can be directional but copper oxides are semiconductors. Their orientation might be related to grain orientation - a question for metallurgist.

AFAIK dielectric affects speed of current. This speed is not a light speed but closer to 60% of it (5ns/m). I believe this speed is inversely proportional to square root of dielectric constant. Teflon dielectric offers the highest speed up to 85% of the light-speed.

Dielectric absorption is ability of dielectric to store and return energy. I'm not sure how it affects the sound but it can be shown, that charged and discharged capacitor will start building up the voltage again without any external source - just from the energy stored in dielectric and we're not talking microvolts but rather volts. Especially bad in electrolytic caps.
kijanki's avatar
kijanki
4,452 posts
 
As fate would have it the audio signal is not the current. The near light speed refers to the signal not current.

Electric current is flow of electric charge, that moves near light speed in the wire. Electromagnetic wave on the outside of the cable moves at the same rate. In electronics, a signal is an electric current or electromagnetic field used to convey data from one place to another. Speed of both depends on dielectric - it is called "Velocity Factor". Electrons move at very slow rate called "Drift Velocity". Electrons are not always necessary for electric current since in the fluid ions carry electric charge.
kijanki's avatar
kijanki
4,452 posts
 
Electric current is a very slow flow of charges, while
energy flows fast

I'm not sure where you got it. Electric current is a flow of charge. Charge
moves in the wire in speed close to speed of light. It has nothing to do with
slow motion of electrons and charges they carry. It works pretty much as
stack of balls (electric charges) - you hit first one and the last one moves
instantly.

http://www.uu.edu/dept/physics/scienceguys/2001Nov.cfm
kijanki's avatar
kijanki
4,452 posts
 
Al, link works if you remove last characters after "9".

Their test proves what you just said - digital cable is not exactly symmetrical presenting slightly different characteristic impedance on both ends. This is very different from directional properties of wire alone carrying analog audio signals.

Many people believe that we should be able to determine that cables are not directional if they present the same measurement from both sides hence two cables with the same measurements should sound identical. I don't believe this to be true. I seriously doubt that one can measure any difference between oxygen free copper (thousands of crystals) or zero crystal copper that comes from continuous casting process - a slow cooling in heated molds to avoid crystallization. Best instruments wouldn't be able to measure this but many claims it makes a difference. Would I be able to tell the difference chopping off 3' of one of the speaker cables - most likely not but my cables are very neutral sounding. Perhaps audio possesses a little bit of black magic?
kijanki's avatar
kijanki
4,452 posts
 
Scvan, don't forget to measure amplifiers and speakers as well, because as we all know if things measure the same they have to sound the same and when they measure better they have to sound better :)
kijanki's avatar
kijanki
4,452 posts
 
Scvan, even assuming that we know everything (we had no idea about existence of transient intermodulation until 70') certain things might be very difficult to measure. How do you propose to measure signal propagation speed in the cable or characteristic impedance and dielectric absorption. What about shielding? How do we test coupling characteristic of different types of electrical noise (capacitive, magnetic, electromagnetic). What frequency spectrum and what type of modulation shall we use to emulate real life conditions.

People who learned about R,L and C believe, that everything can be measured. There is a thread "Capacitor log Mundorf Silver in Oil" on Audiogon running for years (currently 2588 posts) where people discuss sound of capacitors. Would you tell them that two capacitors of the same RLC have to sound the same?

How do you propose to evaluate digital cable that in my opinion is system dependent and might even sound different in identical systems at different locations.

We don't even have clear way to measure amplifier's power and the one listed as the strongest might actually be not the loudest. Perhaps testing has some value - 20W amplifier is clearly not 200W but other than that testing IMHO is a joke. Are you, for instance, sure that 1% THD tube amplifier has to sound worse that 0.01% SS amp? Would amplifier with wider bandwidth always sound better? If anything, price or weight might be better indicators of sound quality.
kijanki's avatar
kijanki
4,452 posts
 
Mceljo, there are thing that cannot be measured but still can be optimized. You can see (oscilloscope) and hear the evidence of Transient Intermodulation but it is very hard and there are no standards to measure it. In addition amplifier with great other specifications can actually sound horrible. It gets extremely complex when you add system synergy.

Often praised high Damping Factor in my class D amplifier is DF=4000. If it is good, then Atmasphere amplifiers with DF<1 (4000 times worse) should sound horrible, right? Atmasphere amps also have 10x higher THDs - they should sound very bad, right? Atmasphere designer must be one of those "Mad Scientists" :)
More to discover