SH Spotlight Can you hear the "directionality" of interconnects and speaker wire? Kevin LaTour can.

Discussion in 'Music Corner' started by Steve Hoffman, Dec 24, 2004.

  1. Doug Sclar

    Doug Sclar Forum Legend

    Location:
    The OC
    Belden 8451 is the type of cable I used to use for wiring studios and many projects including the sound system at the Hard Rock Hotel. It is also the cable I originally used with the telescoping technique I mentioned above, for unbalanced circuits. Since it has 2 conductors plus a shield, I would use the red conductor for signal, black for ground, and shield drain wire connected at one end only, tied at that end with the black conductor. Note that I used this cable back in the 70's and early 80's before the preponderance of 'audiophile' cables which many claimed sounded better in professional use. The 8451 IMO was an OK cable but had a fair amount of capacitance compared to some of the larger diameter cables. This would seem to indicate that this cable would work better with lower source impedances than it would with higher impedances, where the capacitance might come more into play. 8451 is a fairly thin cable but extremely easy to work with, and especially with the foil shield and separate drain wire. This also led to it's popularity for studio wiring where the wiring harnesses can get pretty massive. Many of the audiophile type balanced cables were much much harder to work with. I must admit that I haven't personally compared 8451 with 'audiophile' cables in professional applications, but always assumed that the audiophile cables could sound better in many situations as I've discovered they often do in hi-fi systems. . Once again, in a professional environment, most cables are low impedance and balanced which would seem to me to lessen their effect on the signal they pass.
     
  2. LeeS

    LeeS Blue Note Fan

    Location:
    Atlanta
    I have been in situations where I have heard directionality but its subtle and there are more often times I struggle to hear it. It's very system dependent.

    I don't agree with Lord Hawthornes comment on science measuring this. That's another discussion but it seems well established that science can't fully measure audio effects.
     
  3. LeeS

    LeeS Blue Note Fan

    Location:
    Atlanta
    There are some snake oil salesmen in the cable business but two good guys I respect and know are George Cardas and Bill Low of Audioquest. Here is what Bill Low says about directionality:

    Now here is what George thinks about metrics and audio:

    George Cardas, CEO, Cardas Audio

    A cable’s ability to replicate a waveform, such as a square or triangle, is one measure I use. High resolution programmable oscilloscopes can find the thumb print of many audible anomalies. FFT analysis and harmonic distortion testing can also be a predictor of anomalous behavior. There is a very interesting AES paper presented by Jon Risch at the latest AES convention, in which he explains a system for measuring cable distortion using a TEF-20 and a PHI series of tones (AES Preprint #4803, A New Class of In-Band Multitone Test Signals, AES website, www.aes.org). It clearly shows differences between cable and cabling systems, such as bi-wiring. His system plots harmonic distortion in cable current transfer. I am now working on a commercial implementation for this system.

    Correlating measurements with audible performance is part of a continuing, evolutionary process. My designs are well-formed internally before the prototype runs. Usually the results are very close to expectations. In the final analysis, I find that I switch back and forth constantly, but listening is always the final determining factor.

    Correlating measurements to anomalies is easy, if that is all that is desired. However, having a measurement for all the different sounds we hear would be like trying to establish a measurement for all that we smell or see. We have a good set of tools now, if you can work with a TEF-20 and Jon Risch’s program or really understand a Tektronix TDS 350 or other programmable scope. With these tools we can predict that a component will sound bad or possibly even not so bad. As far as a measurement for "awesome" or "state-of-the-art" or "this is the best system I have ever heard" listen to the music!

    Bio Notes: George Cardas has a gift for mathematics and electronics, and a love of music. He holds several U.S. Patents for cable stranding, pressure differential microphones and connector designs. George loves working with other designers, helping musicians reproduce their music.
     
  4. lynnm

    lynnm New Member

    At The Risk of Annoying!

    With all due respect to Steve and others who support the notion of directionality of cables.

    Directionality would be meaningful only if we were dealing with DC. Audio signals are AC. In other words the electrons that represent the sounds we hear from our speakers swing back and forth between positive and negative voltages umpteen times per second and the recording/reproducing equipment must track those changes accurately.

    In addition since we are not dealing with sequential pure tones but with a mixture of voltages that are in phase with each other and out of phase with each other equally as often,pure tones and harmonics of several different orders both positive and negative are inevitable, I thank whatever Gods there may be that the notion of conducter directivity is pure nonsense because if it were true we could not enjoy the delights of sound reproduction and recording.

    The argument might be made that incorrect connection would not necessarily totally cancel out signals but merely degrade them. Again I will say nonsense If that were true then one must assume that the quality of any given recording has as least as much to do with the "polar correctness" of the wiring in the recording studio as the skills of the recording engineer. A serious listen to the albums engineered by Steve and a few others will quickly disabuse anyone of that notion!
     
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  5. Metralla

    Metralla Joined Jan 13, 2002

    Location:
    San Jose, CA
    Electrons don't swing - they are monogamous little buggers, although a bit of a downer. Always so negative.
     
  6. MikeyH

    MikeyH Stamper King

    Location:
    Berkeley, CA
    I posted a yes; I believe it's not just the wires, but the way the insulation is manufactured and combined with the wires that makes it asymmetrical. I'm not sure if manufacturers know which way is 'right' or if they test/listen and make a choice.

    It's not a big deal; a lot smaller effect than cleaning connectors, for example. I wouldn't like to guess right or wrong way round blind like in the first post, though I'd express a preference or not on hearing both.
     
  7. OcdMan

    OcdMan Forum Resident

    Location:
    Maryland
    Steve said that Kevin LaTour was correct over 20 times in a row. My math isn't too good, but if he's guessing correctly 21 straight times, isn't that like a 1 in 2,000,000 shot at getting all of them right? So for the skeptics out there...what's the explanation?
     
  8. Taurus

    Taurus Forum Resident

    Location:
    Houston, Texas
    I've never done any tests on my own interconnects but do follow the arrows. I have also heard of the single-ended drain concept dsclar is speaking of & though I'm not very knowledgable on such matters, I thought it might have some merit because while the power from a wall outlet is AC, most newer equipment uses a polarized plug: one of the plug's blades is connected to the chassis of the receiver, drill, etc, to make it safer to use since that blade is supposedly connected to the house's ground.

    And I've heard of people solving humming problems in a system by reversing one or more (non-polarized) plugs on certain components that are all plugged into the same power strip.
     
  9. cvila

    cvila Forum Resident

    Location:
    USA
    Are you saying that scientists (or whomever) have developed all the measurment tools in the audio realm that they will ever need and closed the book on it? Wasn't jitter heard before it was measurable?
     
  10. WVK

    WVK Forum Resident

    Location:
    Houston
    Kevin should take up on the challenge offered by the folks posting at "rec.audio.high-end"
    newsgroup. They offer at least $5000 to anyone who can distinguish between "competently designed" cables. This should be easy money for someone who hear cable directionality.

    WVK
     
  11. lynnm

    lynnm New Member

    "Electrons don't swing - they are monogamous little buggers, although a bit of a downer. Always so negative."

    Great line !! :biglaugh:
     
  12. This poll got me to looking at my set up, and I have it all wrong. On my SACD player I have 1 pair out of 3 pairs going "the right way." Now I have to make some time and re-hook up my SACD player with all of the arrows pointing the right way. :help:
     
  13. LeeS

    LeeS Blue Note Fan

    Location:
    Atlanta
    I think what makes the subject tough is that the science is not understood but it is heard. Many professionals in the studio have discovered directionality. I learned about this from Bob Katz. You could really hear a difference if the interconnects on some of the equipment was wrong. I guess the "science mesures all" crowd may harumph but in many recording projects this is considered real.
     
  14. LeeS

    LeeS Blue Note Fan

    Location:
    Atlanta
    Yes. Bob Katz from Digital Domain did some very early work on this. The science caught up later. Same with microphonics in tubes. Same with amplifier THD stats. Same with cable metrics (I, C, R)...

    Anyone notice a pattern here? :D

    If we wait for science to catch up we all may miss the train.
     
  15. WVK

    WVK Forum Resident

    Location:
    Houston
    Wasn't jitter heard before it was measurable?

    FYI:

    ">Well, science "learned" that they could be made better by eliminating jitter.
    >Until discovered, no one knew about jitter.

    Not true.

    Sampling theory was first formulated mathematically by Nyquist in
    1928 and formally proved by Shannon in 1949. Shannon's work was
    directly applicable to PCM which was well established at the
    time. T1 carrier used PCM to multiplex 24 analog telephone
    signals into one digital channel (1.544Mbps) and transport the
    signal for hundreds of miles.

    The telecom industry solved the issues of PCM and jitter and
    deployed vast networks based on such three decades before the
    audio CD. The designers of the early CD players should be
    faulted for not ulitizing the prior public research or even basic
    undergraduate comm theory.

    H. Nyquist, "Certain topics in telegraph transmission theory,"
    Trans. AIEE, vol. 47, pp. 617-644, Apr. 1928.
    C. E. Shannon, "Communication in the presence of noise," Proc.
    Institute of Radio Engineers, vol. 37, no.1, pp. 10-21, Jan.
    1949."
     
  16. Robin L

    Robin L Musical Omnivore

    Location:
    Fresno, California
    Like John Curl always said: "If you can hear it but you can't measure it, you're measuring the wrong thing". People who are regarded as having "ESP" types of gifts can also be regarded as people who possess greater bandwidth. That person who reads the cards for you might have a keener sense of smell. Seriously folks, how are you going to scientifically measure those differences that make an audio system preferable for Mahler?
    I spent a fair amount of time hanging out with Ric Schultz, so I'm sure that cable makes huge differences in sound quality. I've spent a fair amount of time recording and found all sorts of ground related problems/situations, so I know that directionality is important at times.
    Something that makes a much bigger difference than directionality is connectors and the hook-up wire you find in components. Getting rid of the RCA ins/outs and hardwiring with high quality wire will always improve sound. It's not always practical (rarely is, really) but it's always audible. I've removed all the crap wire from power amp output to speaker terminal between my HK430 receiver and my Infinity 2500 speaker (replacing the wire with 12 guage silver-clad copper) and this made a huge difference. In fact, I have strong reason to believe that power amps should come with very low resistance cables, hard-wired as close to the output devices as practical.
     
  17. LeeS

    LeeS Blue Note Fan

    Location:
    Atlanta
    I'm afraid it is true. Telco firms may have figured out the theory in the cited papers but implemented solutions did not exist in the early 90s except in rare instances. Audio engineers thought that CD playback was perfect before people like Bob Katz and others discovered the problem. I was part of the team at Chesky at the time and I watched as Bob first started playing around with the effects of jitter. Trust me on this one, Bob was regarded by many as on a major tangent at the time. Of course, he proved them wrong in spades and others like Julian Dunn offered up the theory side later to explain what the engineers had discovered. Some of the seminal work was done by Bob Harley who measured jitter in CD transport devices for Stereophile at the time.

    As for telco, I suspect their solutions were less involved since they were working on voice reproduction, a less complex effort than the full music spectrum with more transients, etc. Also, to my understanding the jitter solutions offered up did not discuss the nanosecond and picosecond jitter issues we are now working on.

    So I stand by my claim. Science followed on the existence of jitter and the difference it caused in different CD transports.
     
  18. LeeS

    LeeS Blue Note Fan

    Location:
    Atlanta
    Probably true but difficult to implement in practice. Inductance, capacitance, and resistence are all important in good cable design.
     
  19. WVK

    WVK Forum Resident

    Location:
    Houston
    Isn't there is a difference between science not being aware (as you claim) and science not being utilized?

    WVK
     
  20. Ron Stone

    Ron Stone Offending Member

    Location:
    Deep Maryland
    The discussion of problems with jitter, wire directionality, etc., and who discovered what when, reminds me of the promo literature from one cable company.

    The cable company's literature said something to the effect that they spent a good amount of time and money to discover that there wasn't anything about cables and sound transmission that Ma Bell didn't already know some time ago. I thought it was refreshingly self-deprecating, and seemed to make sense on the surface of it. Certainly one of the world's largest companies, trying to transmit small signals through cables laid across continents and oceans, was going to underwrite some significant cable and amplification research.
     
  21. LeeS

    LeeS Blue Note Fan

    Location:
    Atlanta
    Yes, but either counts if the discussion is about science measuring everything at one point in time. Think, for instance, how much better CD playback in the early 90s and late 80s would have been if audiophiles and scientists would have found jitter's sonic impact sooner. Fortunately, audiophile engineers are always experimenting and there is a high end cd transport market. Again, this is another example of work done for super wealthy audiophiles that has trickled down to help us all.

    Ron, I don't think this is true anymore. There have been real advances in cable mfr such as some of the Nordost technqiues and resulting patents. It is too over-simplified to say Ma Bell knew everything in the 30s. Technology does in fact progress.
     
  22. Tony Plachy

    Tony Plachy Forum Resident

    Location:
    Pleasantville, NY
    I vote never bothered to find out. I have heard the difference between cables but there is just too much to do to run this experiment, maybe someday. :sigh:
     
  23. stereoptic

    stereoptic Anaglyphic GORT Staff

    Location:
    NY

    In a thread about speaker phasing a few months ago Steve H mentionned that the speaker wire is directional also. Luckily, when I checked mine, all 4 speakers had the wires in the proper direction. It would have taken a while to reroute my speaker wires to correct this!
     
  24. Rob LoVerde

    Rob LoVerde New Member

    Location:
    USA
    Hmm, directionality in wire. I'm intrigued!

    Well, AC current being bi-directional...remember it's alternating current meaning 'back and forth'. That means that it really should not make a difference which way your cables are connected, really. But the Kevin LaTour story is pretty amazing...
     
  25. Tony Plachy

    Tony Plachy Forum Resident

    Location:
    Pleasantville, NY
    Rob, It is not that simple, AC just means plus and minus deflection from neutral, directionality means a preferred driven path and a preferred return path, a much more complex situation.
     

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