Directional speaker cables - switching direction

Jea48, directionality of a metal conductor is produced by the orientation of the crystal structure as it is pulled through the final die. As least that's what I think. The directionality is independent of the velocity of the signal, I.e., the audio signal. I also do not happen to think the dielectric material affects the velocity of the signal. As I already said I think the velocity of the signal is fixed (constant) for a given medium, I.e., copper or whatever. Now if you are asking me how the dielectric material affects the signal,I actually don't know. I bet it's complicated though. Wink, wink.
12-18-14: Geoffkait

Geoffkait,

Thanks for the response.

directionality of a metal conductor is produced by the orientation of the crystal structure as it is pulled through the final die.

That's what the likes of Bill Lowe of Audioquest and the late Bob Crump preached for years. There are countless others in the same camp as you know that preach the same theory. And until someone comes up with a better explanation that's good enough for me.

Here is a post of the late Bob Crump's.

◾Re: maybe rcrump... I don't know, but... rcrump 06:45:41 09/30/00 (11)

In Reply to: Re: maybe rcrump... I don't know, but... posted by Greg R. on September 29, 2000 at 19:47:48:


Solid core wire is extremely directional so just mark the end with some masking tape as it comes off the spool. Orient the wires so you have piece of masking tape at either end and terminate the wires. Throw it on a MOBIE or whatever overnight and then listen to it noting which way gives the highest image height. This is the correct orientation.
If you run the signal and return wires in the same direction you will end up with hot spots in the stage, normally at or close to the speakers, low image height and have a gaping hole in the middle of the stage...Keep in mind I am referring to the sound of the stage (reflections) not the individual instruments spread across the stage....Interconnects or speaker wires that have pianos wandering all over the stage normally have their signal and return going in the same direction....

Here is another post of Bob's from the same thread.

◾Re: Is stranded core directional also? rcrump 03:59:51 10/02/00 (2)

In Reply to: Re: Is stranded core directional also? posted by steve b on October 01, 2000 at 18:05:36:


Steve, I don't want to speculate why wire is directional, but it is as poor Greg has found in a later post....I spent about three months playing with such things before I released my commercial interconnects and speaker wire and went about as crazy as Greg is going right now and can't tell you how much wire I trashed as I forgot to mark it with some masking take as I took it off the spool....Directionality in wire will be measured some day as it appears to be an FM distortion and wandering pianos (small phase changes with frequency) will be a thing of the past. Until then use your ears to discern directionality of wire. Stranded wire likely suffers from a lack of focus compared to solid core as some of the strands go one way and some the other, but this is pure speculation on my part.....Just enjoy the ride!

http://www.audioasylum.com/cgi/t.mpl?f=cables&m=12332

>>>>>>>>>>>>>

I also do not happen to think the dielectric material affects the velocity of the signal. As I already said I think the velocity of the signal is fixed (constant) for a given medium, I.e., copper or whatever.
12-18-14: Geoffkait

How do you explain the audible differences when flipping cables made from solid core silver conductors? Surely you have experimented and have heard the differences.
.

The revelation that digital interconnects and their direction can introduce large differences in measured jitter was quite a shock. The differences heard between digital interconnects—and in their directionality—have now been substantiated by measurement

.
>http://www.stereophile.com/content/transport-delight-cd-transport-jitter-page-9


The Why? Who cares.... The point is, there was a difference. A measurable difference.
.

12-18-14: Geoffkait
I also do not happen to think the dielectric material affects the velocity of the signal. As I already said I think the velocity of the signal is fixed (constant) for a given medium, I.e., copper or whatever.

That is not true, Geoff. What Kijanki said is correct. For starters, see this Wikipedia writeup. Many other references can be found which will further confirm this. Widely varying propagation velocity specifications for various cables utilizing copper conductors can also be found.

12-18-14: Jea48
An experiment for those of you that use a CD transport and a separate DAC. If your digital coax cable has a solid core center conductor try this experiment. First listen to a good sounding CD with a strong female voice. Find a particular track you like and listen to it closely a few times. Now flip the digital cable end for end and then listen again. One good CD that comes to mind is, Etta James "Love Songs" track 1) "At Last". Also try a good sounding CD with a piano solo. Post back your results.

I don't use a separate DAC, but FWIW I can hypothesize a reason why a symmetrically designed digital cable may sound different, under some circumstances, depending on the direction in which it is connected. My hypothesis, though, has nothing to do with the wire itself having directional properties, and says nothing about the possibility that a symmetrically designed cable conducting analog signals may be have directional properties.

The connection between a digital cable and its connectors will have an impedance discontinuity and inaccuracy to some non-zero degree, which will result, to some non-zero degree, in some fraction of the amplitudes of whatever RF frequencies it may be asked to conduct being reflected back toward the source of the signal. I would expect the magnitude and character of that impedance discontinuity to not be totally identical at the two ends of the cable, due to small differences in solder application, crimping, etc., and perhaps even to dimensional tolerances in the connector.

Also, the output impedance of the component driving the cable and the input impedance of the component receiving the signal will not be precisely accurate.

Therefore the impedance mismatches between the cable and each of the connected components will differ depending on which end is connected where. And digital audio signals contain frequency components extending well into the RF region, up to at least tens of MHz. (Keep in mind that the risetimes and falltimes of the signal contain significant frequency components that are much higher than the clock rate and the data rate).

Depending on these factors, and also on the length of the cable, and also on the data rate that is being transmitted, the resulting reflections may very conceivably affect waveform quality at or near the mid-point of positive-going and negative-going transitions of the signal, those transition mid-points being what the receiving circuitry responds to. Degradation of those parts of the waveform will affect jitter, and therefore potentially sonics, to some degree. And that potential degradation will, per the earlier parts of this explanation, be affected by which connector is mated with which component. It will also be affected by whether the more significant of the two potential mismatches is at the receiving end or the transmitting end, and by the degree of impedance mismatch at both ends (which will affect how many back and forth re-reflections occur until their amplitude becomes insignificant).

See this paper for further discussion of the effects of impedance mismatches and waveform reflections on jitter, although the paper does not address the question of directionality.

If all of that sounds a bit far-fetched, IMO it is less farfetched than an assertion that wires themselves have directional properties to an audibly significant degree.

Best regards,
-- Al

P.S: My post just above was written before Jim's post immediately above it appeared. I haven't yet read the Stereophile article he linked to, but I'll post back later if it prompts any further thoughts.

Best regards,
-- Al

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?