What makes directional speaker cable directional is the screen (or shield or braid depending on which terminology you prefer). To reduce noise, this is normally earthed at the source end. Earthing both ends can lead to an earth-loop which may induce mains-hum. Using a screened cable also affects the impedance of the speaker as seen by the amp, most quality amps can handle this without problem, but on a cheaper amp this can be detrimental to the sound.

 

If you use screened cable without terminating the shield then you have wasted your money.

 

If this fails, try rubbing the cable with snake-oil.

 

so my answer: reality.

 

If you are making the cable yourself, fitting your own terminators and connecting the shield at the amp-end, then okay, it does not matter if the little arrow on the cable points towards the amp or the speaker, so to be pedantic, it's a Myth

 

 

 

Personnally I think shielded speaker cables are a waste of time, effort and money, and any unshielded two-wire cables that are labeled as directional are fraudulent.

 

Mike, you haven't stated your view on this subject: Myth or Reality?

 

 

I have both sorts on different hifi and simply have never thought about making comparisons by unhooking the cables and exchanging them to compare.

 

 

 

 

Just to be certain , Mike!!  you are aware that Unidirectional wires (this means they have an arrow pointing the way it should be cabled)  are not speaker cables, but used between the Hifi elements, (but not the speakers). I could be wrong on this issue, but I have yet to hear of speaker cables that are unidirectional (unless you're speaking of connecting the red connector of amplifier  to the red connector of speakers and the black to the black, which should ALWAYS be done anyway)

 

 

 

 

As for whether it is possible to make unidirectional cable, yes it is but this is feasible only at the foundry during the manufacturing process of the wire and its different alloys. Whether the connectors (end pieces) can be manufactured to be unidirectional, I have no doubt either. Part of my job is about testing different metals (but copper is not one of them) in their resistivity (not resistance as in Ohms, even if that does come in the process) and magnetism properties on the finished products as they age.

 

 

 

 

So I say reality and no myth. Whether this unidirection makes a real audible difference to another high-qual wire, I am much less positive, though.

 

 

 

"These plaited conductors are then over-sheathed with a flexible transparent PVC jacket side by side in the same shotgun formation as the twin interconnect, and one conductor is marked with a polarity arrow. This arrow indicates the preferred direction of signal flow: from the amplifier to the speakers."

 

/edit: Which is a complete nonsense - there is no such thing as signal flow. The signal propagates down the conductor, but the current flow is a.c. - it goes in both directions - it is this fundamental error which is the basis for all these directional claims.

 

i have used two makes of speaker cable that claim to be "uni"directional, Hugues, "QED" made in UK and "Kimber" speaker cables made in USA, which i believe are marked from the point of manufacture.

 

 

 

There are two types of small-signal interconnect: balanced and unbalanced. Balanced has two inner conductors which are the signal & return path and has an earthed external screen (eg XLR type cable) - unbalance cable has a single inner conductor (signal) and the outer screen is also used as the return path (eg RCA connectors). Neither are directional.

 

You can buy balanced cable with RCA connectors - these cables are psuedo-balanced, the screen and the "return" conductor are connected at source and the screen is left "open" at the receiving end. These cables are marked as being directional with the arrow pointing to the "open" end.

 

That is the technical explanation and in theory it is possible to tell the difference if you get the direction wrong, but for the carp I listen too I doubt I'd notice

 

Aside from the explanation Darqdean gave you about the AC signal!

 

Again Mike, this is where it is useful to see which cables you're talking about.

 

Indeed the speakers cable transport an AC-like signal to the speaker, but this one is riding on a slight DC current (needed to power up the speakers>> please don't tell me these are working on water and fresh air). BTW!! Important that both speaker cables be the same lenghts (in case of stereo, I don't know for 5.1) even if one is much closer to the stereo. The entire length should be deployed and NEVER wound up.

 

 

With unidirectional cable between say your CD deck to your amp >> the info can only go one way and is not an AC (either O or 1), therefore only going one way anyway.

 

 

mystic fred wrote: Sean Trane wrote:   Just to be certain , Mike!!  you are aware that Unidirectional wires (this means they have an arrow pointing the way it should be cabled)  are not speaker cables, but used between the Hifi elements, (but not the speakers). I could be wrong on this issue, but I have yet to hear of speaker cables that are unidirectional (unless you're speaking of connecting the red connector of amplifier  to the red connector of speakers and the black to the black, which should ALWAYS be done anyway)      i have used two makes of speaker cable that claim to be "uni"directional, Hugues, "QED" made in UK and "Kimber" speaker cables made in USA, which i believe are marked from the point of manufacture.

 

 

Fred, the two brand names you mention are unknown to me (as a matter of fact I don't know any cable manufacturer off hand or by memory ) so I don't know how serious they are.

 

For my speaker cable (cut to the dimension I asked them and left bare), I had to mark the black side with a black marker and make sure that at the other end I marked the colour on the same side.  So for my use since the cables comes from a 50m spool, only the connectors coud be unidirectional unless there are repeated arrows down the cable as well as colour markings down the whole lenght of the cable.

 

 

 

For me the most important quality for speaker cables is shielding (this is where the signal is the most vulnerable),  and to make sure that they do not run alongside other cables >> never wind up your cables either, this produce capacitance and induction phenemenon, (this might appear a bit crazy , but even at these low tensions/power,  best not taking chances.

 

They are not working on water and fresh air - the water would be harmful.

 

There is no DC component in the speaker cable - it there was it would seriously damage your speakers. The Power Amplifier amplifies the music signal (I will refrain from calling it AC from now on) to such a level that it can drive the speaker coil.

 

(AC can power things - that's how washing machines and light bulbs work!)

 

 

-------------
What?

 

Well you have digital cables from DCC and CD decks to the amplifier and the optic links (this is the future for most intra-hifi links) work also in digital .

 

As far as the speakers are concerned I think I wrote a little too quick here. You're right (I was thinking of those computer speakers that have power plugs to them >> they're the ones I see when I type my answers) they can power themselves from the signal.

 

Edit: However should those Hifi speakers (not PA speakers) be needing to power itself up, the last thing I'd want to to is introduce a power suply inside the resonance box of the speaker or even under it.

 

Digital is a whole different ball-game and you are moving from Audio into RF (which is why your digital cable is a co-ax cable like your TV) - in these cases optical is better.

 

I thought I was too until that post where I mixed up my different set ups on my different stereos.

 

 

 

 

 

 

Truth or Myth? Cable Directionality

You are here: http://www.russandrews.com/lookup/1/region/UK/currency/GBP/customer_id/PAA0944061807323PUHVMEKCKDVEGIVK/article-Russ-Masterclass-russ_on....htm - Russ' Masterclass > http://www.russandrews.com/lookup/1/region/UK/currency/GBP/customer_id/PAA0944061807323PUHVMEKCKDVEGIVK/article-Truth-or-Myth-Cable-Directionality-russdirectionality.htm - Truth or Myth? Cable Directionality javascript:history.go%28-1%29"> javascript:history.go%28-1%29 - Go back to the previous page

All cables - yes all cables have signal directionality. By 'directional' I mean that in one direction, the sound is slightly louder, has lower distortion, is a cleaner, smoother, sweeter, and has a deeper bass and overall wider dynamic range. Cable directionality is measurable and quantifiable, if not fully understood. The amount of directionality, or the difference between one direction and another varies from cable to cable. I first discovered cable directionality when I was doing research and development into cable design in 1979. I was auditioning a microphone cable as an interconnect. The drain wire in the cable could be grounded at either end and a friend suggested that I try it each way round (meaning to change the grounding from one end to the other). I misunderstood him, however, thinking that he meant that I should turn the whole cable around. I found to my surprise that the cable actually sounded better one way than the other - it was directional! I tested the effect on my wife (a blind test, not telling her what I was changing) and asked her to describe the change in sound. She described exactly what I had heard, so I knew I wasn't imagining it, even though my electronic 'education' said it couldn't happen. I have since discovered that the telecommunications industry is well aware of cable directionality and applies this knowledge when laying cables. The engineers at KIMBER KABLE are now able to measure cable directionality and quantify it using some new and very expensive test equipment. When you buy a cable from us, its directionality is marked by either an arrow on a paper label, or on the heatshrink near one end of the cable. The signal follows the arrow, so on an interconnect connecting a CD player to an amplifier, the arrow points towards the amplifier. On a loudspeaker cable, the arrow points towards your speakers. If you have a cable that isn't labelled with its directionality, see our tip, right, on directionalising cables at home. Postscript: Customer Craig Sawyers e-mailed us to say: "Interesting comments about cable directionality, Russ. That it occurs is undoubtedly true, and that it is poorly understood is also true. But your comments about communications professionals knowing about the effect is, also surprisingly, true! When we moved into our house about 10 years ago, I had a company based in Luton, who I knew, come and install the TV and FM aerials. As he was uncoiling the spool of high spec, double shielded satellite cable on the lawn the engineer said "got to make sure I get this the right way round". I asked him why, and he said "no idea how it works, but you get a better picture when we connect it the right way round". So there we go - it isn't only the audio fraternity that notice cable directionality!"

 

this is the point, Mike, cables are not made to be directional, thay just are - nobody really understands why .  and it doesn't affect the price or saleability - even cheap cables are directional.

 

 

 

I have sent an email to Kimber Kables, (surely that should be Cimber Cables - swaping K's for C's is all a bit too much Kamelot and Konkhra for me), asking if they could furnish me with more details on this quantifable test method. I await their reply.

 

Mike is correct on all counts - if the cable were electrically directional then the symmetry of the signal would be affected - ie distorted on one half of the signal - swapping the cable would only swap the distortion to the other half but the net result would be the same... distortion.

 

::thinking out loud::

 

Because this distortion would be asymmetrical it would consist of predominately even harmonics - the same kind of harmonic distortion you get from the output transformer in a valve (tube) amplifier. Valve amps are generally regarded as "warmer" than their solid-state counterparts for this reason. However since this asymmetric distortion is the same in both directions it does not explain subjective directionality.

 

In all of the (web)published info on this subject many listeners say that the signal sounds warmer when the cables are swapped while the others say it is brighter (i.e. the opposite). Aside from sugesting that the actual direction of these "directional" cables is purely a matter of personal taste, it tends to imply that there is even harmonic distortion in one direction (warmer) and odd harmonic distortion in the other (brighter). Odd harmonic distortion occurs when the music signal is distorted equally on both the positive and negative cycles (ie symmetricaly).

 

This leads to another possible explanation in that in one direction there is odd harmonic distortion and in the other there is none. What people are perceiving as a warmer sound is actually the true sound that the record producer created and the brighter sound is the cable distorting the signal symmetrically. This still does not explain the mechanics of subjective directionality.

 

A cable is a passive network, electrically it is described by http://en.wikipedia.org/wiki/Transmission_line - transmission-line theory, which describes the two wires (signal & return - not left & right) as a ladder of series inductors (L) and parallel capacitors (C), this is symmetrical and (being passive) works in either direction. The inductors are the wire itself while the capacitors are the plastic insulation that seperates the two wires (often called the dielectric... and there is a whole mess of audiophile psuedo-science regarding dielectrics - including one idea that the dye in the insulator can leach into the wire). This L-C effective-circuit is a low-pass filter, with a roll-over frequency in excess of 100KHz (depending upon cable length), which is why you cannot send video signals down an audio cable. Because audio cables are designed to have a flat frequency response across the entire audio spectrum the electrical characteristics of the cable cannot be affecting the colour of the sound like the tone-controls on an amplifer would.

 

For there to be directionality in this L-C ladder then either there is either directionality in the L or in the C element of the cable. All internet discussion on this subject centres around the wire itself, which suggests that the directionality is in the wire. However, since the conductors are multi-strand then this directionality would have to exist in all the individual strands and that they are all aligned in the same direction.

 

Because multistrand cables are spun together from multiple reels of single strand wire this would mean that the spools of wire are all of identical directionality. As strange as it may seem - this is feasible since the wire is made by drawing a ingot of copper through increasingly smaller dies, then spooling it onto a huge drum and then re-reeling it onto smaller spools for sale to audio-cable manufacturers - so the direction of manufacture will be constant for all spools. If it is the drawing process that imparts the directionality into the inductance of the wire then it will be electrically measureable. And since both wire and the ability to measure inductance have been around for a few hundred years, someone would have spotted this by now. Even cable manufacturers who sell directional cable only quote one value for the inductance of their cable (and one value for the capacitance).

 

On curious comment I read on this subject is that the directional effect is less noticable after 20 minutes or so.

 

This process is refered to a lot and is called burn-in, impling that there is an annealing effect going on, which, by inference, means that heat is involved in re-arranging the structure of the copper. Heat requires power. The power in an interconnect is smaller than miniscule - the resistance of the cable is typically 65miliohms and it is terminated in 47Kohms. This means that for a 1 volts rms music signal 1.46uV is lost in the cable, which equates to 40attoW of power (40E-18W), which is best refered to as four-fifths of nothing divided by infinity. One fanciful explanation I have read for this is that the electrons flowing through the wire are rearranging the copper crystals to find the path of least resistance, which is wrong on so many levels I'll not even bother to comment.

 

Another cable-direction issue that is costing Audiofiles a whole heap of readily disposible cash is in the power cable that connects the hi-fi to the national grid. But that's another story.

 

 

1st reply back from Kimber states that they have never made such a claim...

 

awaiting their second reply

 

Most valve amps will drive the load through a transformer so are truly balanced output (and also floating, no direct ground connection).

 

As regards speaker cable, I agree entirely.

 

i too would be interested to know what  "new and very expensive test equipment" they use to test directionality, might write to them myself and ask for a report!

 

 

 

I've got the feedback from Mr Diamond of Kimber Kable. The copper wires they use are basically amorphous in structure, and hence not directional. He says that directionality occurs after a burn-in period. He also states that they have some expensive test equipment and can perform some special tests at special frequencies that reveals observable changes that standard audio-band tests would not show.

 

 

 

 

 

So the real irony is not that Audiophile believers are wasting their money buying unnecessary directional cable, but that we sceptics and non-believers could be using "directional" cable anyway.

 

 

 

OWWWCH 

 

 

You don't sound so mystic now.

 

"Problem/Concern Description:  cable directionality.

cable directionality, fact or fiction,  is the subject of heated discussion
on many internet forums - i asked Russ Andrews for their opinion on the
subject and they referred me to you - do you have instruments that can prove
which direction particular cables are suited for? or is it something that
establishes itself after burn-in time?

many thanks in anticipation

steve trowbridge"

 

 

 

 

I'm brilyunt at speling - it's just my typing that lets me down.

 

Professor Peter? Fairly tall handsome looking chap, generous to a fault, never argues or raises his voice, would give you the shirt off his back, always gets his round in at the pub?

 

Anyway I did try swapping - and surprise, surprise, not difference.