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Discussion Starter · #1 ·
At a neighborhood garage sale for one buck I found 3 pairs of 3 ft audio cables that I plan to use with my Yamaha AVR's analog audio outputs to drive external power amplifiers. They look well made with 6 mm jackets, gold plated connectors, and with molded large grips at each end. Very nice. However they are a bit unusual. On each cable there are arrows showing the signal flow direction following the product label like so:


RCA Home Theatre - Audio Cable - Signal Flow >>>>


I hooked them up both ways: first, with the signal flow and second, opposing it. I didn't hear any difference. Aren't audio cables supposed to be bidirectional?
 

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Quote:
Originally Posted by Gizmologist /forum/post/20822646


Audio is an AC voltage and as such it is totally non directional. The arrows bit is another audiophile screwball marketing gimmick and nothing more.


I hope you did not pay more than a dollar.

Exactly what he said.



Sounds like you got a nice deal on some cables (even if you paid $3 for all of it).
 

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I distinctly remember presenting this question to my college physics prof. Me, fresh faced, young and dumb, I pondered the vast array of audio tweaks I had read about and discussed at studios and hifi salons. Me, being a teenage "sound guy" for a band, I frequented studios auditioning monitors and talking shop with techs, engineers etc. However many of the audio aspects I was learning about through the late seventies made great sense,...and held up to scrutiny, but the one that I couldn't get past was hifi guys claiming directional signal flow in cabling.


So, the first opportunity I had as a freshman at college, I stayed late in Physics and discussed this issue with the smartest dude I'd ever met,...this physics prof of mine. As I began chatting, he wouldn't stop doing what he was doing. But I continued explaining my audio interests and I nervously asked him about cabling products possessing directionality. Then he stopped dead, quickly swirling this idea around and chuckled,.... saying the only way would be some aspect of dis-similar metals. He continued talking aloud, working through the possibilities, dismissing them all. I remember this well because it was extremely cool watching him work this through aloud.


I stood there awkwardly, and he concluded by asking if there was anything else. I said no, and he stopped and very confidently emphasized "focus on the basics, and get them right, before moving on to the minutia". I'll not likely forget that.


For me, the takeaway is something I see quite frequently here, and elsewhere. There are so many loudspeaker placement 101 , and similar mistakes made. Oftentimes the enthusiast mistakenly delves into cabling, power quality, DACs etc, without getting the core aspects correct. If the primary elements are well executed, go for it,...experiment with whichever component you wish. Bernie Grundman claims he can detect changes in wiring, resistors, caps, connector bodies,... etc, he's also a businessman soliciting his work, and his golden ear hearing. His mastering room acoustics and signal path has been well vetted, and I'm sure it's quite resolving. That said, go for it Bernie.


Thanks



btw, without realizing it,....I prolly learned more about audio tweaks in Psych 101, then my EE and Physics courses combined
 

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Directional arrows might be legitimate on some cables. If unbalanced interconnect cable is based on a twisted pair, then shield should be connected on receiver side only. It improves interference rejection by 1 dB or so.
 

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I remember reading a reply from a cable manufacturer in a FAQ section, their answer was it helped ground loop issues with source components to AVR when connected properly, arrow in direction of flow, source>AVR (not agreeing just repeating).
 

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Quote:
Originally Posted by ap1 /forum/post/20823324


Directional arrows might be legitimate on some cables. If unbalanced interconnect cable is based on a twisted pair, then shield should be connected on receiver side only. It improves interference rejection by 1 dB or so.

After seeing your reply maybe it was interference, was a long time ago.
 

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The directional aspect I'm referring to, was an audiophile listening to both directions, and determining which was optimum
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by ap1 /forum/post/20823324


Directional arrows might be legitimate on some cables. If unbalanced interconnect cable is based on a twisted pair, then shield should be connected on receiver side only. It improves interference rejection by 1 dB or so.

Thanks to both ap1 and jackbuzz for shining some light on the subject.


Makes more sense now. Although it may be a screwball audiophile marketing gimmick, aka 'snake oil,' it really looks legitimate then in theory. Whether it makes a difference or not in practice is purely academic for me because my HT system has no hum nor RF issues for me to worry about. But I suppose it makes nice, sometime humorous discussion for audio theorists. Thank you FOH for the chuckles.


Anyway, I'll leave them connected wrt the signal flow. I guess it can't hurt.
 

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Quote:
Originally Posted by ap1 /forum/post/20823324


Directional arrows might be legitimate on some cables. If unbalanced interconnect cable is based on a twisted pair, then shield should be connected on receiver side only. It improves interference rejection by 1 dB or so.

Yes, I was going to mention that too. But when I build a balanced cable with the shield lifted on one end, I simply label that end "SHIELD LIFTED".


Now if you read some of the more recent "Pin 1 problem" papers, they suggest this not be done on a true balanced interface. Pin 1 is supposed to be connected directly to the chassis at the connector. Some manufactures run it back to the signal ground buss and that's what causes the pin 1 problem. So if your gear properly designed, there is no reason to lift shields on balanced cables.
 

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Quote:
Originally Posted by ap1 /forum/post/20823324


Directional arrows might be legitimate on some cables. If unbalanced interconnect cable is based on a twisted pair, then shield should be connected on receiver side only. It improves interference rejection by 1 dB or so.

Interesting. A conflicting POV below.

http://www.bluejeanscable.com/articles/humrejection.htm
 
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