directional cables

Discussion in 'Playback Devices' started by Frank Zimmerman, Oct 9, 2003.

  1. Frank Zimmerman

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    whitch way does the arrow point in the reciever or my amp...need alittle help here.......
     
  2. Heath_E

    Heath_E Stunt Coordinator

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    The amp. The arrow would always point to the next component in the chain. The theory is that directional cables reduce the amount of noise/interference from one component to the next.
     
  3. Frank Zimmerman

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    thax pal................
     
  4. Tor S

    Tor S Auditioning

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    I've always found the concept of directional cables a bit... er... illogical. I may be very wrong, of course. Could someone please explain the scientific side of this? Thanks in advance.
     
  5. Saul R

    Saul R Extra

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    "I've always found the concept of directional cables a bit... er... illogical. I may be very wrong, of course. Could someone please explain the scientific side of this? Thanks in advance."

    Ditto! IMO, this might be another misleading/unfounded/fraudulent claim of the industry. The whole notion of having cables that are directional - the signal passes with less intrusion, impedance or modification in one direction versus the other -- is undoubtedly suspect. In other words, I find this curious due to the inherent nature of AC where electrons simply rush back and forth in sympathy with the applied signal. A directional device is a semiconductor, and will act as a rectifier. If these claims are even a tiny bit correct, I certainly don't want any of them between my preamp and amp, because I don't want my audio rectified by a directional cable. Just my 2¢
     
  6. Tor S

    Tor S Auditioning

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    My thoughts exactly, Saul R.! [​IMG]

    Sounds like a ripoff to me... [​IMG]
     
  7. anthony_b

    anthony_b Screenwriter

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    I don't believe in directional cables myself...
     
  8. FeisalK

    FeisalK Screenwriter

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    they're good for DC based systems [​IMG]
     
  9. Brian L

    Brian L Cinematographer

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    IIRC, a direction cable is one where the shield is disconnected at one end. A "normal" interconnect has the shield connected to the outer ring of the RCA jack at both ends.

    Not having it connected at one end will eliminate the possibility of a ground loop between two pieces of equipment.

    Now, given that the gear you are connecting is normally in the same rack, connected to the same AC source, and grounded to the same point, I would doubt that there would be any difference in ground potential that would cause a ground loop. And if there was, would it be audible?

    I tend to classify this with all the other outrageous, fraudulent claims made by certain cable vendors.

    Of course, thats just my opinion.

    BGL
     
  10. jeff peterson

    jeff peterson Supporting Actor

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    Actually, if I recall correctly, there is a physical difference in each terminated end of the cable. I think the ground (usually the covering woven cable) aka shield isn't connected to the terminating plug on one side but is on the other. What this brings to the table? I couldn't tell you.

    I'm sure someone with more knowledge will step in here to verify.
     
  11. Heath_E

    Heath_E Stunt Coordinator

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    First, let me state that I don't own or advocate buying directional cables. I just happened to be familiar with the theory and was able to offer assistance to the original poster.

    With that being said, take a look at the quote below. This was taken from a FAQ at monstercable.com, and best sums up the directional cable theory.

     
  12. Brian L

    Brian L Cinematographer

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  13. Saul R

    Saul R Extra

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    Health E, I still remain skeptical after the marketing rhetoric. Noting that I’m familiar with the design of Faraday cages, once again I think this is another ill implementation of a sound physical concept. The foil shields, braids and/or outer conductor in conventional coaxial cables are the same or in direct physical contact throughout the entire length of the cable. It is my understanding that in order to apply such principle one would have to isolate the shield. Therefore, any advantages that would be possible to obtain from such design in a coaxial cable are inherently lost due to the structure of the cable itself. With that said, I would think that currents generated by electromagnetic flux would inevitably express themselves at both ends of the cable. Consequently, IMO, the orientation of the cable should be irrelevant.
     
  14. Saul R

    Saul R Extra

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    Upps!
     
  15. Saul R

    Saul R Extra

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  16. Saurav

    Saurav Cinematographer

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  17. Wayne A. Pflughaupt

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    Lifting the shield at one end is not uncommon in pro-audio applications, like studios for instance. However, in that situation we’re talking about balanced signals where the signal (-) does not ride on the shield. I’m not so convinced it’s functional with unbalance signals.

    I will give Monster credit for noting that the reasoning behind their directional cables is “theory.” However...

     
  18. Saurav

    Saurav Cinematographer

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    Ah, I see what you're saying. I was thinking along the lines of stuff I've done with umbilicals between power supply boxes and audio amplification boxes, but there the shield is an independent conductor from any of the voltage-carrying conductors.

    I've read accounts of people who had hum with long subwoofer cables that disappeared when they reversed the cable, which happened to be 'directional'. Don't know if it was a repeatable test though, could have just been a loose connection that got tightened with the connectors being removed and re-attached.
     
  19. Saul R

    Saul R Extra

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    Saurav, admittedly, I overlooked that Monster uses twisted pairs for their "unidirectional" cables. However, unlike power cords and XLR cables, where drain wires and/or shields are independent (and the concept could be properly applied), such separation is not possible with unbalanced cables. I tend to agree with Wayne A. Pflughaupt when he said:



    It's a curious gimmick nonetheless.
     
  20. Saurav

    Saurav Cinematographer

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    Yup, I overlooked the fact that the shield was connected to the shield at one end, even if it was insulated from it through the length of the cable.

    It might be possible to make this work by ensuring that an RF frequency signal has a lower impedance to earth in one component than the other (and then hook up the cable so the sield is connected at that end). Maybe by using different values of resistors/capacitors to connect the RCA barrel to earth, or something like that. That way, even though you have 'equal' connectivity at audio frequencies, you'll have different impedances at RF frequencies. But that's firmly in the realm of 'what if', as I really doubt that commercial home audio gear does anything like that.
     

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