Exotic Materials and Cable Construction
A lot of discussion of quality cables focuses on the materials used in cable construction. Just as with any physical product, the materials cables are made out of influence their performance characteristics, and so people want to know that the cables they're buying are made from the best possible materials. Many high-priced cables are made with materials for which special claims of high performance are made. The most common among these are silver instead of or in addition to copper, "oxygen-free" copper, and Teflon. We'll address each of these in turn and explain what they are, what their characteristics are, and whether they make sense for particular applications. Initially, it's perhaps helpful to point out that professional cables of the highest quality are routinely made without resort to any strange, exotic or expensive materials. If you look inside a typical audio or video production facility, you won't find it wired with silver-plated cables, oxygen-free copper cables, or (except, as we'll explain, in limited circumstances) Teflon-insulated cables. Broadcast studio engineers--people whose livelihood depends on the signal getting through with the lowest possible distortion and losses--rely on cables from companies like Belden and Canare, made with ordinary high-quality materials. People who spend millions of dollars on high-definition studio gear rely on these cables not because they're out to save a buck at the cost of quality, but because they are looking for the best possible product. Let's take a look at some of these materials and consider how they bear on quality cable construction. Silver or Silver-Plated Cables Broadcast-quality cables are generally made with copper conductors; but it's not uncommon, in the consumer a/v market, to run into cables made with silver, or silver-plated copper, conductors. Why is this? There is one respect in which silver is a better material for cable construction than copper: it is slightly (about 5%) less resistive (that is, more conductive) than annealed copper. "Resistance" is the property of any material which causes some of the electricity that flows through it to be converted into heat, and it's fair to say that resistance, in cables, is a bad thing--the less the better. All else being equal, lower resistance ought to be a good thing, and therefore one might think that silver would make for a better cable than copper. That would indeed be so, but there are some other factors to take into account. First, the resistive loss in high-quality copper cables is already extremely small, because copper, though marginally less conductive than silver, is an extremely conductive metal. For example, Belden 1694A's center conductor resistance is 6.4 ohms per thousand feet. In a very long home theater run of 50 feet, then, the resistance of the conductor is 0.32 ohms, representing a minuscule cause of signal loss in a 75 ohm impedance video circuit; a solid silver conductor would drop this resistance by about five percent, resulting in a truly infinitesimal improvement. This infinitesimal improvement might be worth something under extreme circumstances, all else being equal--but all else is rarely equal. First, silver is a more brittle material than copper, compromising the cable's flex-life. To solve this problem, silver is often plated over a copper wire--diminishing the conductivity benefit. Second, the conductivity benefit, as often as not, is offset by a reduction in wire gauge. Going from an 18 AWG conductor to a 20 AWG conductor, for example, results in an increase in resistance of over 50%; this swamps the conductivity benefit of silver, so that an 18 AWG copper conductor is more conductive, not less, than a 20 AWG silver or silver-plated conductor. When the comparison is between full-sized copper cables and silver-plated mini-coax of tiny gauge, like those one sees in many popular silver cable products, there's no contest; full-sized copper cables are dramatically more conductive, silver or no silver. Oxygen-Free Copper Many cables today are advertised as using "oxygen-free copper," copper which has been annealed in an oxygen-free atmosphere. OFC is popular in audio cables, and has begun to make inroads into the video cable market as well. We all know, of course, that oxygen is bad for things made from copper. Copper oxidizes and turns green and flaky; in so doing, it loses its high conductivity and begins to fall apart. But the amount of oxygen present in conventionally annealed, non-OFC copper is so tiny that it simply isn't a factor in cable quality. We have cut into pieces of Belden coaxial cable twenty-five years old that have been used in radio transmission applications--and found them clean and bright, completely lacking any sign of oxidation. Modern coax is better still, with nitrogen-injected foam dielectrics that keep oxygen entirely away from the center conductor. As it is with silver, there's nothing wrong with OFC; but electrically speaking, OFC wire is indistinguishable in audio and video applications from ordinary annealed copper wire. Teflon Dielectrics and Insulation Teflon is a special case, in one interesting sense: while audio and video cables made with silver or OFC are seldom used by professionals, there are plenty of professional-quality cables made with Teflon, for reasons we'll get to in a moment. Teflon, of course, is familiar to us all as a coating on cookware; but it has certain interesting electrical properties as well which account for its use in cables. Insulating materials like Teflon vary in their ability to isolate conductors electrically from one another, and this property is characterized mathematically as the "dielectric constant." The best dielectric, from a purely electrical standpoint, is a vacuum; air is very nearly as good. But of course, when we're making coaxial cable, it's hard to use pure air as a dielectric because we need something relatively solid to keep the center conductor from coming into contact with, and shorting out to, the shield. A good dielectric for cable manufacture needs to be physically stable as well as having a good dielectric constant. Two materials that meet these criteria are polyethylene, used in the vast majority of precision video cables, and Teflon. If we look at the characteristics of Teflon and polyethylene side-by-side, what becomes apparent is that Teflon has a lower dielectric constant; it is, in that sense, simply a "better" dielectric than polyethylene. If we were to make two coaxial cables, otherwise identical to one another, but produce one with polyethylene foam dielectric and the other with Teflon foam dielectric, the Teflon cable would have lower capacitance. Low capacitance being good, that'd be a good thing--right? It would indeed; but there's a problem. The dielectric constant, capacitance, and the cable's characteristic impedance are all tied up together. If, in our example, the polyethylene cable had a 75 ohm characteristic impedance, for use in video, the Teflon cable would have a higher impedance, and would present an impedance mismatch if used in a video circuit. In order to correct the problem, we need to make the dielectric and shield smaller. When we get to 75 ohms impedance, we wind up with the same capacitance we had in the polyethylene cable. In other words, just because the Teflon is a "better" dielectric doesn't mean we get a "better" cable; it just means we don't need quite as much Teflon to achieve the same cable characteristics that we get using polyethylene. Teflon's much more expensive, but a video cable with Teflon offers no performance enhancement over one made with polyethylene--so why the heck does anybody buy Teflon cables, anyhow? The answer has nothing at all to do with electrical performance, and everything to do with fire safety. Polyethylene, when exposed to fire, burns and gives off toxic fumes. This becomes an enormous hazard in a modern office building, where huge bundles of telephone and data cables are run through spaces which are also used for ventilation, because a fire in one part of a building can rapidly spread toxic fumes to the whole building. Teflon, by contrast, is highly fire-resistant and does not give off toxic fumes as easily. Because of this fire safety issue, cables which are routed through a plenum--that is, a dropped-ceiling area used as a ventilation return--are required to have a "plenum" rating, and Teflon, being both highly fire resistant and an excellent dielectric, is used in most plenum-rated cables. Perhaps partly because of the higher cost of Teflon cables, some people believe that plenum versions of precision video cables perform better than their non-plenum counterparts. For example, one will sometimes see Belden 1695A, the plenum version of 1694A, recommended as a performance upgrade from 1694A. In fact, however, the performance specs on these two cables are virtually identical, and there is no reason to favor 1695A--unless, of course, you need that plenum fire rating. We sell Teflon-dielectric cables, like Belden 1695A, alongside our polyethylene-dielectric offerings. If we thought that there were performance advantages to, say, Belden 1695A over Belden 1694A, we'd be the first to recommend it--but our experience has been that the two are, as the specs would suggest, completely indistinguishable. Teflon-based cables can be superb, but no more so than their less expensive, polyethylene equivalents; our recommendation is to use them if you need a plenum fire rating, but to save your money if you don't. In Conclusion... Fine materials and quality manufacturing practices make the best cables; but the best materials for cable manufacture aren't always the most exotic or fancy-sounding. Not only are quality copper wire and nitrogen-injected PE foam dielectric great materials for building a precision video cable, but manufacturers like Belden make the best use of these excellent materials by employing them in well-engineered manufacturing processes, with tight tolerances. The result: cables of the highest quality, relied upon worldwide by professional broadcast engineers when the quality of the signal is of the utmost importance. by Blue Jeans Cable (reprinted with permission) |
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     Reviewer Unregistered guest |
According to my 30 years of reviewing experience, professional cable and professional amplifier have no match in terms of sound quality to those so called crazy "hi-end" cable and amplifiers. Like you said, professional audio engineers in general don't believe and don't care for hi-end cables or amplifiers. Almost twenty years ago, I was invited by Monster Cable to visit Hollywood's famous recording studios, witnessing them replacing their Belden cable to Monster products...I agree with you that hi-end cable have little different by measurement that proved surpassing the "professional" cable. Strange enough, hi-end cable do sound better, more refine, have better depth, more 3D and life. Different brand of hi-end cable have their own sound signatures -- sounding different, better in some way or slightly less good in other way. If you mersure them, I am sure the different could be from very insignificant to non. I can only say that there must be something we do not know. Such as how to mersure, or simply our best equipement is not up to it. |
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Let sanity prevail Unregistered guest |
The notion that exotic cable sounds any different to standard cable displays a complete lack of understanding of physics. Nobody has been able to demonstrate any of the claims of these manufacturers, apart from the simple fact that if you think something's going to sound different, it will - even if it's identical. Your mention of corrosion with respect to oxygen free copper is a complete misunderstanding of materials science, ie what oxygen mixed in with the copper actually means. It doesn't have anything to do with corrosion, it just means that there are oxygen atoms buried within the metal's crystalline structure that disrupt the crystal matrix and supposedly interfere with electrons when the cable is being used. Again there has been no demonstration of this having any effect. |
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Oops Unregistered guest |
"The notion that exotic cable sounds any different to standard cable displays a complete lack of understanding of physics." If you had actually bothered to do listening test with quality equipment the differences between cables is readily apparent. But why cling to this existance that if current physics theories cannot explain it, its not true? Sure, a lot of the cable claims are snake oil but that should not take away from the fact that there are auditory differences between them |
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L. Unregistered guest |
Proper double blind tests have never revealed a difference between exotic cables and normal, reasonably-priced cables. As Let sanity prevail said, though, if one thinks something is going to sound different, it will - it's just something the human brain does, like an optical illusion for the ears. |
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Chastity Unregistered guest |
That would make it an auditory illusion. ;) |
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Unregistered guest |
Why am I the only one who seems to notice that the articles written on this site are written by...PEOPLE WHO HAVE SOMETHING TO SELL YOU. Cable performance, regardless of material composition, is affected by other things such as shielding, it's affect on the conductors, inductance, etc. When an article pops up by, oh, let's say a writer who names his company after a decidedly casual pair of pants, and his scientifically based partial explanations of what cables to choose just happen to coincide with the products he sells, don't you think you should be just a little bit skeptical? |
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BBG Unregistered guest |
Anybody else get the impression that this guy may work for Belden or paid by them to write this article??? LOL. Now lets be serious. Anyone that actually sits down and takes the time to listen (if they know what they are listening for) can clearly hear a difference in cables. The main problem is that most people hear music as one mass sound. In order to tell the difference in any change in your system, you will have to be able to disect the sound. Some are just not capable of doing this especially if they have never been exposed to music like playing an instrument or so on. Most "engineer types" are number crunchers and live and die by those numbers. So any so-called engineer already has a preconceived notion and typically biased because "the numbers don't lie." Most engineers that I know and ran into over the years say amplifiers do not make any difference as well. I cannot understand that logic either. The problem is when you have people that make the claim that there is no difference, these people simply do not understand music or know what to listen for. I can go grab anyone off the street and do a blind test and they will NOT hear a difference until you educate them on what to listen for. I am not saying that you tell them what the change is, but to simply point out an instrument or voice to listen to and block out the rest. Once you point out what to listen for, then everyone comes to the same conclusion about what happens to the sound without it being told ahead of time. Like Reviewer pointed out in the first post, you have to listen to all aspects like depth and width as well as tonality, dynamics and separation. You cannot focus on numbers because I have heard some cables with identical resistence, capacitance and inductance sound completely different from one another. It is true, not always the most expensive cable or "exotic" cable sounds better. For example there is a manufacturer out there that puts a battery on their cables. Very expensive company, but when I put this cable up to another one for about a tenth of the cost, the cheaper cable sounded as good as this battery mumbo-jumbo configuration. It even got bad reviews because it did sound ok, but nowhere near worth the cost. Let's think about the comment made about how professional studios don't use these expensive cables. Why should they? They have hundreds of thousands of dollars wrapped up in equalizers and everything is digitally altered. Ever wonder why most bands nowadays don't sound anything like their recorded version? They have this capability to alter any frequency at minimal intervals to get it the way it should be. Why spend money on cables when they need to have the equalizers for some of these so-called artists nowadays? Anyone that says they don't obviously never been in a recording studio. Until a person is sat down and educated on depth, width, tonality and dynamics, this argument in reality is pointless and neverending to those that are unfortunately ignorant. I am not saying that all companies are truthful to their claims, but anyone that says wire is wire is living in their own world. |
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pmc0607 Unregistered guest |
BBG is right, the public needs to be educated first, so they can understand and hear the difference in cables I have a friend that is a Engineer and he told me the same, there is no difference I brought over to his house my Audioquest Caldera(no battery) and Python interconnects. Hook them up to his system and listen to one song and he admited that it sounded better, He spend the rest of the night trying to figured it out. He when and bought better cables and starting to ask me about the tweaks in my system. |
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Anonymous |
Is it just me or does anyone else feel like they just read a Belden commercial or maybe a Blue Jeans one? True or false, this reads more like a plug for someone then anything else............and that is disappointing. Canare and a host of other cable manufactures are just as good as Belden. Why no mention of them? |
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New member Username: GgcPost Number: 1 Registered: May-05 |
"L", or "Let Sanity Prevail" are electrical engineers. They always fall back on the textbook terms of Transmission Line theory. "Wire is just wire" is their battle cry. I love it when they throw in "Physics" to make you think they know something. If you actually pin them down, they know a 5 awg and a 48 awg conductor will not perform equally as speaker cables. So they have to admit that gauge size does matter. Ask them if if copper and aluminum have equal conductivity. Then they have to admit that conductor material does matter. You can go down the line of features offered by the legitimate high-end cable manufacturers, shielded vs unshielded, stranded vs solid core, etc., and they will say that all these things do make a difference. But, show them a piece of wire costing more than $.39 per foot and they'll scream "Snake Oil". These guys live to piss on other people's parades. They either say that no blind A vs B tests have been done to show high-end cable is better, or they say that all blind A vs B tests show that high-end cables make no difference. Anyone in the High-End industry knows that every legitimate cable manufacturer does countless hours of A vs B testing. This is how they develop the unique sound of their product lines. Every high-end audio publication has written numerous articles comparing cables. If all cable sounds the same, how can they compare them? I know, it's all a conspiracy. Hundreds of thousands of audiophiles, world wide, and thousands of audio manufacturers are just trying to get them to buy something their textbooks don't really talk about. Anyone who has sat in the "sweet-spot", with the lights down really low, listening to music that is in tune with the resonance their bodies, knows wire makes a difference |
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New member Username: Walt_bPost Number: 6 Registered: Oct-04 |
I have purchased cables from BJC and have found their prices and product knowledge to be top notch. Plus, they do not high-pressure just to make a sale. BJC does use Canare connectors to terminate several of their cables, so BJC isn't just a "Belden thing". I replaced several runs of builder installed RG6U cable with Belden cable and objectivley noticed improved PQ via cable feed. BJC is simply making a valid point, i.e., that one does not have to pay an arm and a leg for good performing cables. What one saves in cable expenditures (away from exotic cables) can be used toward upgraded components, e.g., perhaps a digital audio receiver with HDMI or perhaps upgraded speakers. For that matter, visit the following sites to perhaps stir matters up even more: http://www.audioholics.com/techtips/audioprinciples/interconnects/ComponentVideo Cables.php http://www.audioholics.com/techtips/audioprinciples/interconnects/cablessciencer eligion.php http://www.audioholics.com/techtips/audioprinciples/interconnects/speakercablefa ceoff01.php |
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BBG Unregistered guest |
Walt, no one said that Belden or Canare are crap. Like it or not, there are better cables out there. Just as some car fanatics are willing to pay thousands of dollars for 1/10 of a second off of their 1/4 mile time. Audiophiles are just as dedicated to spend what they feel is worth it to them to here Clair Marlo or Jessica Pigeon or whoever they love sound as if they was right in front of them. What I have a problem with and I think this speaks for a majority is someone saying that cables don't make a difference, but at the same time trying to promote theirs. Every cable company that I know offers low cost cables for those that think wire is wire at the same price point and even less that perform as good as Belden and Canare. And all cable companies offer what they consider better quality. Belden and Canare do as well and they are constantly pushing their product as much as any other company. If one doesn't believe, then don't buy their product and if there really is no difference in the cables a company is making or claiming, then that company will eventually fade out. The odd thing is that the "Engineers" always resort to things that are statisically proven. That is their nature. What they forget about is how long it took for people to come up with those theories and prove them. Not everything in the world is black and white and for engineers to say "well the numbers don't lie and so that means it does not happen" is a totally blind and ignorant statement considering that many more of us agree that cables make a difference than those that don't. Could you imagine what the world would be like today if people have always had this closed minded mentality? Perhaps someday there will be someone out there smart enough to figure out solid reasons and correlations just as the laws of physics were eventually proven. |
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New member Username: Walt_bPost Number: 7 Registered: Oct-04 |
BBG, we are on the same page. To that end, what you state is well received in that your points are valid. Also, I think that the BJC folks were simply trying to make a point that more money does not necessarily mean better quality, e.g., I can't count the number of posts that mention Monster Cable's outrageous prices for what can be achieved at much less the cost. Hence, the reason for the Audioholics articles citations. Bottom line is that individual tastes and preferences vary. What ultimately matters the most is the end user's own eyes and ears. (A bit of irony is that I recently made a purchase of Monster Cable 14 guage speaker wire but at a very decent Internet price.) I just spent hours of research for all of my home theatre components that are just now coming in; very good Internet prices from reputable (warrant honoring) vendors. I don't rely only on just what BJC states or anyone else's sole representations. What matters is when unrelated, reputable others state the same thing. I often pay heed which has proven quite beneficial not only in price, but in quality audio and video. |
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Unregistered guest |
Folks, the level of contraversy here is kind of nuts. My background is a masters in mathematical science and an undergraduate minor in space physics. I was certified by IEEE in 1975 as a relay engineer. In relaying you impose a carrier wave on top of the 60cycleAC current to prevent bad things like system blackouts. The key calculation is a series of 0 sequence numbers that tell you how a wire and load are going to distort frequency under changing load conditions. There are differences in each of these wires due to the orbital structures of the atoms that compose the wire. The dspf orbital configuration. The conductor that produces the least distortion is aluminum. If you go look it up on the periodic table You will find that it has a dsp-5 structure. The fewer orbitals the less opportunity the electrons have to change energy levels and introduce distortion in the wave pattern that is being sent electically down the wire. The problem with aluminum is that at room temperaturesits resistance is relatively high resulting in IsquaredR losses which reduce the sound level you want and increase the damping factor which reduces clarity. The cure is to supercool the conductor. At room tempertures, nickel and copper will have the least distortion because they have dsp-6 orbitals. Silver has dsp-7 orbitals. That is roughly double the number of energy levels that aluminum has and about 33% more energy levels than copper. Just like the spectral adsorption lines in the sunlight for each of these metals the changed energy levels will color the electric current as it goes through the wire. Elements in the same row as gold have a vastly more complicated structure becasue the structre at that point includes f orbitals for a fdsp-8 structure. What you are saying is that you happen to like the changes that are made in the electric current becasue of the energy adsorption characteristics of a particular condutor. Things really get complicated becasue the same element can have different valence values. For example copper has two stable states Cu+++ and Cu++. Each of those will have a different effect on how the conductor sounds. The detailed explanation lies in the Schroedinger wave equation and the Heisenberg uncertainty principle. So on a pure physics basis copper is going to produce a truer signal than any of the others but it may produce characteristics that are the result of transfer of energy in a manner that is not pleasing to the ear. No conductor is going to have output exactly identical to the input. I am using Sonic Link Maroon connectors between my preamp and amp to kill excessive brightness in the high end. That brigthness occurrs due to the design of the tube circuits on my phono preamp and preamp being oversensitive to 10k and higher frequencies. If you are familiar with the Shure test record the violins have shreaking sound in the top frequencies. The nickel reduces the intensity of the high frequencies. When I first got out of the army in 70 I went to work in Ford's racing engine program. We used to joke that here are two ways to go fast: cubic inches and cubic dollars. The high dollar solutions are not necesarily better than the lower cost ones. For that discussion read Art Salvatore's blog at www.high-endaudio.com. Go to recommended components and then to speaker cables. This man ran one of the highest end audio store in Toronto for twenty five years. His discussion of good old Polk basic speaker wire will lay it all out for you. Yes speaker cables do sound different becasue of their different atomic structures that are the mechanism to transfer thae elctrical energy along the wire. Each one sounds different becasue they are different. What they do is magnify or minimise aberations that are introduced by your components elsewhere in your system. |
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artificialj Unregistered guest |
I think 'rotten' just won. |
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Anonymous |
I second Rotten Rotties' comprehensive analysis taking into consideration the theoretical aspect of physics and its practical application. Simply read some of the cable engineers' white papers--from private companies to various Space/Military agencies--and compare/contrast their minds and products against those of the scientifically uninitiated snake-charmers trying to make that quick buck. Mr. Rotties, thank you for your informative input. |
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New member Username: MohanCoimbatore, Tamil Nadu India Post Number: 1 Registered: Jul-06 |
Better Materials means better Cables. Most of our custoemrs ask for very specific requirement mostly relating quality and endurance. By looking into a cable on the surface will not reveal the inside and cable characteristics. That's why I wanted to share this Cord Making (Telephone instrument cords) here. |
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New member Username: PalistenPost Number: 1 Registered: Aug-06 |
Does anyone have a link or a reference to a documented side-by-side double-blind test of the high end OFC cables vs more "regular" cable to determine if some statistically valid sample of listeners could actually hear a difference? I haven't been able to find that yet. I don't understand if there are such benefits of these cables why can't I find the results? |
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