Time for cables
Cables are one of the elements that constitute an audio system. It is neither more, nor less important than the remaining ones, but it is still approached with suspicion and from a distance by many engineers and music lovers. However, those who have already gone through this stage—St. Thomas's stage—do not need to explain anything. This article is dedicated to them.
Microtuning consists in actions that aim to precisely set up, equip and arrange loudspeakers, electronics and cables. In small steps, we can totally change the sound of these devices. Read our third article on the subject, this time solely devoted to cables.
While preparing the first two parts of the "Fine Tuning" (or "Microtuning") cycle, one related to loudspeakers (Part 1) and the other one to electronics (Part 2), I moved within quite well known and respected borders. Most basic assumptions in these fields are shared by academic engineers that might be called 'theoreticians' and people connected with perfectionist audio, both engineers and music lovers that we analogically call 'practitioners.'
One of the oldest audio cables – the American Insulated Wire Corporation WE16GA, a speaker cable made of tinned copper
Theory and practice
It is obvious that these two worlds overlap and there is no such person as a pure 'theoretician' or a pure 'practitioner'. Despite that, there are dipolar views on both sides—one of the parties has a tendency to minimize the influence of many solutions used in audiophile devices and loudspeakers, while the other party ignores technical basics and focuses only on listening sessions. Which of the parties is right? I would cautiously say that neither.
However, it is not worth wasting time and living cautiously. So, I will tell you that I am closer to 'practitioners,' although rather those who have some theoretical background. It is because theory cannot explain a lot of things that we can evidently hear and that appear repeatedly during every well-constructed listening session. The fact that theory cannot explain them does not mean that they do not exist. It is simply necessary to wait for someone who combines the passion of a music lover, audiophile and scientist, and will try to find out the truth.
Anyway, dipolar views are a fact. So far, we have been talking about things that seem to be obvious—loudspeakers and electronics. When it comes to cables, things are most often very radical: either a full YES or a full NO. The problem is that while the former two fields have been investigated by engineers, scientists and the industry as a whole since the 1940s, thanks to which some common positions have been established, appreciating the meaning of cables in the process of shaping sound is a matter that has been researched for, let's say, the last twenty-five years and therefore it is still controversial.
Cables change sound
That is why it is so difficult and conversations about cables are so stormy. However, checking the simple fact that cables change sound in different ways, depending on the conductor used, dielectrics and their topology, as well as plugs is very simple—it is enough to listen. For that purpose, one needs a well set up, i.e. balanced and quite transparent system characterized by good resolution. The difference can be noticed already after five seconds of listening. If there is no difference, it is because the cables are identical, the system is a "bottleneck," or the listener is insensitive to these differences.
Let us assume for the purposes of this article that we agree with the statement above, that it is important to us and that we would like to improve the operation of our systems by optimizing the use of the cables that are included in them. To the point—let us assume that we are FOR it. I will demonstrate a few ways to do it for those of you who are still with me. As a basis, I will use my experience gained at recording studios and on stage, as well as while working in the audio industry. It relies on hundreds of tests, listening sessions and comparisons, both carried out by myself and as part of the activity of the Krakow Sonic Society. I will also make use of external information sources.
The article has been divided into seven parts. The first part is related to the construction of cables, the second one—to vibration damping, the third one—to directionality, the fourth one—to burning, the fifth one—to the influence of cable length on sound, the sixth one—to methods of improving connection between contacts, while the eight one includes a few tips on how to arrange cables.
What is important, the article is to be a guide for practitioners and I want to share my observations and conclusions in it. So, I will try to reduce the theoretical part of the discussion to a minimum and will not engage in a dispute with other points of view. Theory is naturally indispensable, but I leave it to others who are better prepared to deal with it. I offer pure practice.
Construction
The terms: conductor, wire, lead and cable refer to different things but they are often used interchangeably. Theoretically, one might connect devices with one another and the power source using a conductor, i.e. a non-insulated wire or stranded wire. It is virtually impossible in practice, mainly because of user and equipment safety. However, it is much more important that such a connection is sensitive to electromagnetic and mechanical distortion—hence the need to use dielectrics.
A conductor in a dielectric is a cable. It is characterized by three basic parameters: R (resistance), L (inductance), and C (capacity). In reality it is all about their equivalents for alternating current, but in order to simplify things we talk about the trinity: RLC. The parameters are closely connected and if we change one of them, the other two also change. It appears that the following factors influence cable measurement: the arrangement of conductors in a cable, type of dielectric used, type of conductor, type of screen (or a lack of it), vibration damping materials, etc.
Conductor
The most researched element is the type of conductor. Since I remember, i.e. since I started dealing with perfectionist audio, there have been two camps among audiophiles—some think that copper is the best conductor and some prefer silver. There are naturally other solutions, such as silver-plated and tin-plated copper, silver with an addition of gold, as well as cables made of more exotic materials, e.g. molybdenum, tungsten, etc., but copper and silver constitute two poles that set the boundaries for discussion.
The Siltech Triple Crown interconnect made of high-purity cast silver
What effect does this have on sound? It is said that silver cables sound fast and transparent, and are dynamic, but they lack bass base and are often too dry. Copper, on the other hand, is respected for deep bass, a low centre of sound gravity and filling. Indeed, a lot of cables nicely fit in this description. However, I think that it is mainly because it is not always possible to utilize the advantages of a given conductor within a given price range and what one can actually hear is not the cable itself but its errors. When it comes to the best cables, material is not connected with sound in such a simplistic manner.
For example, let us look at the products of the Siltech company. Inexpensive cables made by this manufacturer sound fast and dynamic, are clear and have nice distinct treble. They can be used in systems that are a little ponderous or where we want to obtain transparent sound without colourings on the midrange and treble. These cables lack filling in the low midrange a little. However, something strange happens in the most expensive Siltech models—they sound like the best copper cables but with all advantages of silver cables.
On the other hand, we have copper Cardas cables. And again, cheaper ones sound a little dark, dense and low. All of them emphasize mid bass a little. So, they are excellent for the purpose of putting weight on sound, giving it mass and "effectiveness." This company's cables form large phantom images and a dense network of relationships between instruments—the higher the price of a given cable, the easier it is to hear it. Again, the most expensive series have much more open treble and they are more neutral, because of which they resemble other "copper cables" less.
Let us add that manufacturers try to combine the characters of both materials in silver-plated cables, while tin-plated cables calm the musical message and make the treble softer (e.g. Supra). When it comes to silver with an addition of gold, used e.g. in cables made by Crystal Cable, it makes cables sound warm and dense, but not as open and selective as silver ones.
To make things clear, let me add that not everyone thinks that these changes occur. For example, the owner of the AIX Records record label, Mr Mark Waldrep, writes the following in his monograph on sound in audio systems:
Suggesting that the choice of cables should be made on the basis of sound changes that analogue or digital cables introduce in signal transfer is illogical and results from having insufficient information. […] If you have a cable that has withdrawn treble the moment it supplies signal from signal source to the preamplifier, there is something wrong with this cable. It is necessary to replace it with a cable which does not modify high frequencies.
Mark Waldrep, Music and Audio: A User Guide to Better Sound, AIX Publishing 2018, p. 635
I respect Mr Waldrep and think he is an excellent sound engineer (more about him HERE). However, I can do nothing about the fact that I hear these changes. So, we can choose cables for our own system on the basis of the conductor that is used in them. Generally (and only generally), we can apply the description that I give above. Actually, however, from my own experience I can say that other cable elements are much more important—in fact, the most important.
Vibration Damping
In fact, the material a cable is made of is a secondary thing. Other elements are much more important—topology and dielectrics. There is no simple answer to the question "What is better?" as everything depends on the remaining elements. One of the most important things in cables is mechanical vibration damping. The noise that vibrations produce is called triboelectric noise. It is possible to measure it, but it used to be ignored for a long time, since it was thought it has no influence on sound.
VertexAQ cables or rather their anti-resonance box. Photo: VertexAQ
So, a cable that is well-constructed mechanically will be a little thicker than other cables, unless it is flat, like e.g. Nordost ribbons. I have heard sceptics laugh at thick cables with thin terminals many times. I would then explain that this is not about cheating people but damping vibration. The VertexAQ company did it the extreme way, using regular vibration "absorbers" in the form of boxes including anti-resonance supports in its cables.
In order to improve the operation of resonance-damping elements, it is worth using, or rather necessary to use cable supports. I know this is yet another step towards mastery, as I put it, or another step towards hell, as other people will say, but that's just the way it is. On the one hand, cable supports are to reduce the effect of ground vibrations on cables and, on the other hand, change the capacity of cables by keeping them away from the ground.
Supports of this type are produced by many companies, most often cable manufacturers—Acoustic Revive, Nordost, Cardas, Shunyata Research, Furutech, SSC, and Harmonix, but also manufacturers specializing in anti-resonance supports and racks, such as Rogoz Audio. Each of the companies has a different patent for how these elements should be constructed, because of which their products change sound in different ways. It would be best to test a few of them, as a lot depends on what they are going to stand on, what cables they will cooperate with, etc. It is a also necessary to remember to have quite a lot of them, as the distance between such supports should not exceed 50 cm for rigid cables and even 30 cm for flexible ones.
The Furutech NCF-Booster Signal Connector & Cable Holder. Photo: Furutech
What do they change in sound? They mostly calm it down. They do not slow it down, but extinguish nervousness. Some of them, such as those by Nordost, Furutech and Shunyata Research, add opening to the treble, slightly reducing bass. Other ones, such as those manufactured by Acoustic Revive do the opposite—reduce the treble a little and put weight on low midrange. Generally speaking, however, the effect of using supports is positive. If you do not hear their influence, then the system might have too little resolution or it has bigger problems somewhere else and they conceal the improvement made by supports.
The effect of using cable supports can be heard most clearly in the case of speaker cables, then power cables and, finally, interconnects. It is also worth testing how they work under power cable connectors – a special support of this type is offered by Furutech—the NCF Booster Connector and Cable Holder model. It is worth testing one or perhaps two such Furutech holders, but not more. They work best when a single one is used.
Directionality
Cable directionality is another "ignition point" in discussion. But little arrows on cables and connectors refer to two different things—one of them is connected with the electrical structure of cables and the other one with the inner structure of conductors.
The electrical structure is connected with unbalanced RCA cables made using three-core cable, such as in balanced cables. Positive and negative signal is sent in them using the same cores, and the screen is connected on the side of the transmitter, i.e. signal source. The advantages of such a design, i.e. a lack of a low-pass filter that is created by the screen are obtained only when we follow the instruction, i.e. connect it in accordance with the arrows, i.e. "directionality."
The Shunyata Research Venom SP speaker cables with printed on arrows showing directionality
What might be controversial is another kind of directionality resulting from the crystal structure of conductors. It did not use to mean a thing and the aspect was not given any attention, but alongside an improvement in system resolution it appeared that it does matter in what direction we connect the given cable. Where does this come from? The problem is well-explained by the Wireworld company whose CEO and founder is an engineer attached to measurement:
It's all about grain structure! The microstructure of copper and silver conductors is actually made up of individual grains of the metal. Unavoidable angular patterns in this grain structure can cause cables to perform differently in both directions. Wireworld cables are manufactured utilizing a proprietary Grain Optimization™ process that specifically controls the grain structure of the metal to produce the highest fidelity when the signal flows in the direction of the arrows printed on the cable. Some other brands of audio interconnects are directional because their shields are only connected at one end of the cable. The shields in Wireworld cables are connected at both ends to provide superior isolation from noise.
Wireworld Tech & Philosophy: Directionality in Cables, wireworldcable.com, date of access: 25.05.2019
Crystal structure is formed by wire-drawing—and this is always done in one direction. It is less important in cables cast using the OCC technology, but still appears quite important there. So, let us follow arrows printed on cables. If they are connected the other way round, they usually sound darker, less transparent and lose information.
Burning
The directional structure of cables is strictly connected with another thing, i.e. cable burning. Burning, as a method of ensuring the optimum operational parameters of an audio product has been known for many years. However, even though it is well-known and understood in electronics where it is mainly used for the formation of capacitors and establishment of transistor operating points, etc., in loudspeakers where it is related to forming the flexibility of membrane suspension, and even in turntable cartridges where it is used to ensure the flexibility of bracket suspension, it still constitutes a matter of dispute in the cable domain.
It should not be like this. Burning is a standard procedure used by many companies, similar to another process known as annealing. The aim of annealing is to soften metal—during production, material becomes mechanically hard. It appears that it then has lower conductivity and, above all, "sounds" worse. After suitable temperature processing, it returns to the former state. Cryogenic processing has a similar aim—cooling down quickly to a very low temperature and heating slowly.
Both types of processing serve to order the crystal structure of metal. Cable burning also has a connection with cable structure, but a different aim—minimizing the so-called "diode effect" that occurs when electrons move between crystals. That is why cables with very long crystals are so popular. However, it is about something more, something that we may not fully understand, as OCC cables also undergo burning.
What is burning? It is simply playing music with the use of the given cables for a specific period of time. Everyone who has dealt with expensive cables must have noticed that a system starts to sound better some time after better cables are introduced. The differences are often so big that listeners get the impression the system had been faulty before. Those who think it is nonsense talk about the accommodation of hearing and say that listeners simply get used to new sound. It is hard to disagree with that, as it is definitely one of the elements of this change. But it is enough to compare a cable taken straight out of the box with a cable that has already been subjected to burning, to confirm the fact that they sound different and after some time these differences disappear.
The Proburn cable burn-in accelerator from Blue Horizon. Photo: Isotek
How long should burning last? That depends on cable design, but a general rule says that it is a process which lasts not shorter than a few weeks. However, it is worth being patient and simply listen to music with the cables, as the effects are excellent. Impatient people may use so-called "burn-in machines," i.e. devices that only perform this single function, e.g. the Blue Horizon Proburn the Cable Cooker from audiodharma, or the Nordost CBID-1, as well as discs with appropriate signals that accelerate the process.
Length
The length of signal and power cables is another element of the puzzle and yet another thing that many engineers negate. Let us read this:
Transmission line effects at the typical length of speaker cables should be ignored. As a rule of thumb, we always recommend keeping cable lengths as minimal as possible, but not too short that it compromises accessibility to equipment.
Gene DellaSala, Speaker Cable Length Differences: Do They Matter?, audioholics.com , date of access: 25.05.2019
However, it is enough to listen to the same cables of different length for a short time to see that this is not an adequate picture of reality. Cables of certain length sound better than the same cables of different length. And these are not small differences. I have carried out such comparisons many times (a few dozen times, I think) and the result of these comparisons has always been the same—cable length has an effect on sound.
Nordost, the American company that I have already mentioned, has one of the best research programs in the world (like Wireworld, Shunyata Research, Siltech, Cardas, or MIT) and has created many interesting solutions thanks to measurement supported by listening sessions. During audio shows, it conducts seminars in order to present its observations and prove it to anyone interested that the findings are true. These are very instructive meetings and I recommend them to anyone who cares about learning and is not as dumb as to negate something just because they think it's "impossible."
We will find the following tips in FAQs on the manufacturer's website:
The signal loss on Nordost cables is very low due to the use of extruded FEP insulation and Micro Mono-Filament technology. Nordost cables can run over longer distances with less signal loss than regular cables. However, when planning a system set up, it is wise to keep lower level signals such as tonearm cables and analogue interconnects relatively short. It is better to use longer loudspeaker cables as these typically have much more current and voltage being provided by the power amplifier.
Frequently asked questions: Length, nordost.com, date of access: 25.05.2019
Except for statements related to the superiority of these cables over other cables (even though it is understandable that any constructor considers their product to be the best—otherwise their work would make no sense), it is worth paying attention to the fact that first of all, Nordost thinks that the length of cables matters and, secondly, that it is better to make speaker cables long and interconnects short while setting a system up. What lengths are we talking about?
The minimum recommended lengths of Nordost cables are as follows:
- Power cables - 2 meters
- Analogue interconnects - 1 meter
- Digital interconnects - 1.5 meters
- Tonearm cables - 1.25 meters
- Loudspeaker cables - 2 meters
It is not the only specialist company pointing out that cable lengths need to be adjusted, but no other company has prepared such clear guidelines so far—guidelines that I do agree with, by the way.
I have written about cable length so many times that I've lost count. The statement that has had the greatest impact so far was included in the report from the 72nd meeting of the Krakow Sonic Society entitled Acrolink Mexcel 7N-PC9100 vs Acrolink Mexcel 7N-PC9300. I said that an Acrolink cable of 2 m length "sounded" better than one of 1.5 m length. What is more, another cable of 2.5 m length sounded even better. Completely independently, Witek Kamiński came to similar conclusions and described them in the coverage of the 4th Plichtowskie Sonic Meeting entitled On cats and dogs, i.e. does length matter?.
The Nordost Tyr 2 speaker cable made using the Dual Mono-Filament technology. Photo: Nordost
Nordost wrote about their own cables. In reality, the effect a cable of given length has on sound depends on the cable's structure. From my own experience, I can recommend the following:
- a power cable should be at least 2m long
- an analogue interconnect should not be shorter than 1m, but also not longer than 1.8 - 2m,
- a digital interconnect should be 1.2 - 1.5m long,
- a USB cable should be 1 - 3m long, with exceptions when one can use a USB cable that is up to 5m long,
- speaker cables—minimum 2m long, but should not be much longer than ca. 5m.
This is my opinion, of course—you may think different. The fact that cable length matters, but is not especially important, is mentioned by The Chord Company on their website in the Speaker cable guide (date of access: 13.05.2019). The decision is yours, as always.
Contact
Connectors and power cables are a mobile element of the audio track. Cables used to be permanently soldered to devices and loudspeakers, and had plugs only on one side. Today they have plugs on both sides and the only exception are some cables that come out of turntable arms. It appears that plugs are an important element of such a construction and have at least as much influence on sound as the cable itself. Again, I have written about it so many times that recalling all the articles does not make sense. So, the example I am giving you today is not my article but one written by already mentioned Witek Kamiński, entitled Ja szpieg... Czyli o wtyczkach i innych aspektach audio (Eng. I spy... A few words on plugs and other aspects of audio).
Mr Ken Ishiguro, the owner of the Acoustic Revive company, applying spray to an IEC supply socket—I've been using it myself for two years
But a plug is one thing and a contact is another. Different types of materials are used to enhance it. Among others, they are offered by the Acoustic Revive company. I've been using them for a few years and I can recommend them. We spray liquid on plugs and sockets, including supply sockets. The ECI-50 Conduction Improvement Cleaner is special transparent oil containing tiny carbon particles that fill micro depletions in the surface of metal. It is a solution applied in Japanese laboratories, improving the speed of signal transmission by 20% (as measured). Sound becomes denser and deeper thanks to it. The changes are not big, just a few per cent, but it is worth checking if these are not "the few per cent" that we have been missing. You can read more about it in the coverage of the 88th meeting of the Krakow Sonic Society .
Another equally fantastic solution are products offered by the McKenic company. They sell material prepared by an American specialist for industrial purposes—that is why it is sold in large containers and one lasts for a long time.
Arrangement
The final stage of cable preparation is their appropriate arrangement. The recommendations given so far may be new to a lot of you, but the way cables should be arranged seems to be clear and simple. Let me cut the story short and give you the most important recommendations in a few sentences.
Interconnects and speaker cables should not be stretched tight and stiff. Stresses badly affect connections with plugs, as well as change topology inside cables, which is not beneficial. It would be best for these cables to hang a little loose (interconnects and power cables are a little bit more resistant) and they also should not cross power cables, because the electromagnetic field around the latter has an effect on audio signal. It is sometimes hard to handle this issue because audio devices have power and signal sockets in different places.
However, if we have no choice and our signal cables—interconnects and speaker cables intersect with power cables, let us make sure they intersect at the angle of 90 degrees. It is also worth separating them somehow—the further away they are from one another, the better. Speaker cables should not be coiled—loops are simply coils and they constitute low-pass filters. These cables should be laid straight or in arches. If we have to do something with their excess, let us coil them in the shape of a snake.
A Few Final Tips
I hope I have set the direction for you, at least to a certain degree, and the problem of cables is not that big anymore thanks to it. These are naturally my own observations, even though they are supported by other people and companies, but they are still mine. And there are other views—as I have said, there are a lot of reasonable people who think this is nonsense or an attempt to make music lovers spend money. I cannot help it, as everyone can have their own opinion. Mine is different.
However, you do not have to and even should not agree with me. The beauty of audio results from the fact that everyone can do experiments in the form of individual listening sessions. Only such experiences can give us a basis to say that something matters and something else does not. It is important that the direction of these tests has been set for you.
The problems that I have mentioned are the most important, but not the only ones. There are other issues, e.g.: which are better: balanced (XLR) or unbalanced (RCA) connections? Should speaker cables be of the same length or can they differ in length? Should bi-wiring or single cables be used? How to say something about the role of speaker jumpers in loudspeakers with more than one pair of clamps? Where should speaker cables be plugged if we use such jumpers?
In order not to make it too long, I will only tell you what my choices are, without giving any explanation. Whenever I can, I use RCA connections. Speaker cables can be of different length, but the difference should not exceed ca. 20% (people from the Chord company talk about 40%). There should be a single speaker cable. Jumpers are as important as the cable itself and I always connect signal from the amplifier to tweeter clamps. However, again, this is me and my system and your observations can be different.
I would like to encourage you to carry out tests, listen and read, as only an idiot does not listen for no good reason or negates something without having listened to it, just because they think something is "impossible." Audio, at the level that we are talking about, is an "organoleptic" activity and it is thanks to such experiments that we learn more and more, while the sound of even inexpensive systems is unquestionably better than before.
CRACOW | POLAND
Text: Wojciech Pacuła
Photos: Wojciech Pacuła | Company photos
Translation: Ewa Muszynko
