Tag: audio cable design

Capacitors, Speakers, Cables and Other Magic Stuff

Well more than half a century ago, when I was a kid, the teacher in my high school Physics class did something I will never forget. Let me tell you about it. Maybe you’ll want to keep it in mind, too.

He Blinded Me With Science

One day, as part of his regular lesson, the teacher (sorry, but after all these years, I simply don’t remember his name) brought out an electroscope—a device for indicating the presence and polarity of an electrical charge [https://www.merriam-webster.com/dictionary/electroscope]—and showed us how it worked by using it on one of the batteries kept on hand in the classroom for just such purposes.

He then brought out a “U”-shaped thing made out of three pieces of wood, each six or eight inches long, arranged so that one piece formed the bottom of the “U” and the other two were set perpendicular to it, one at each end and pointing upward, to form its vertical “legs.” ( I  I ) Each of those legs was wider than it was thick, and each had been notched at the “top” (across the upper ends of the U, and parallel to the bottom piece) so that it could act as a holder for one of the next two things the teacher took out and set on the demonstration table.

Those were pieces of (probably) one-inch dowel, each about four or five inches long, to which a thin metal disc, perhaps three or four inches in diameter, had been attached across (perpendicular to) the end, (—I) and which had been drilled-through axially, so that an insulated wire could be soldered to the disc at one end, passed through the dowel, and have a couple of feet of slack hanging off it, with an alligator clip at the other end.

It Gets Interesting

That’s when it started to get interesting: First the teacher picked up each of the dowel/disc/wire assemblies (from this point on, let’s just call them “handles”) and, holding first the disc, then the dowel, then the wire and alligator clip next to the electroscope, he showed us that no part of either of the two “handles” or their attachments was charged. Then he set the two handles onto the notches on the upright Legs of the U-shaped “frame” in such a way that the dowels were in the notches; the two discs were facing each other, perhaps an eighth of an inch or less apart (—II—); and the two wires were hanging-free of the dowels pointing in opposite directions, with their wires loose on the table.

Stored Electric Energy

Finally, he touched the two wires from the handles to that same battery that he had used before and re-checked for charge. Sure enough, the “handles” (or at least their discs and wires) were charged, which he explained by saying that the two discs (the “plates”) separated by the non-conductive air space between them (an air “dielectric”) had formed a capacitor—device for storing energy, which is created any time two (charged) conductors are separated by any non-conductor.

To demonstrate just how much energy had been stored, he then touched the two alligator clips together, and was rewarded with a spark, bright enough for the whole class to see. This, he said, was caused by the release of the stored energy, and proved it by once again using the electroscope to check for charge, finding none remaining.

Things Started To Get Weird

What followed next was when it started to get weird:  First, he re-charged the “capacitor” by again touching the two wires (the alligator clips, actually) to the battery and, with the electroscope, verified that it was, in fact, re-charged. Then, taking one of the handles (—I) out of the frame ( I  I ), he held it up to the electroscope and checked it again. No charge. Then he picked up the other one (I—) and checked it. Also no charge. Finally, he held the electroscope in the space between the two upright legs of the frame, where the gap between the plates had been ( I  I ), and checked that, too. No charge there, either.

Okay, we thought. The capacitor had been taken apart, so there was no more capacitor. No surprise if there’s no charge, right? It seemed only reasonable; but when the teacher re-assembled the capacitor and, once again, touched the two clips together, there was another spark! Amazing!

Where had it come from? Where was the energy stored if it wasn’t in any of the previously known-to-be-charged parts? Could it be in the air in the space that had constituted the dielectric between the two plates? That didn’t seem possible because the air, being fluid, was constantly circulating through the room—including through the space where the gap between the plates had been—so that, if it had been the air that was holding the stored energy, it would reasonably be expected to eventually disperse throughout the room and be lost to re-capture. That that wasn’t the case was proven by the last part of the teacher’s demonstration.

For that, he once again re-charged the capacitor and once again took it apart. This time, though, he had two of the students carry the two “handles” to two opposite corners of the classroom and leave them there until just before the end of the class period.  Then he had them brought back to the demonstration table; re-assembled the capacitor; and again touched the alligator clips together, getting once again—even after all that time—a spark that seemed fully as bright as before.


Magic Applies To Our Audiophile Hobby

But magic that applies directly to our audiophile hobby: Remember what  I said before about any two charged conductors separated by any non-conductor being a capacitor? Well, if you stop to think about it, it should be obvious that it’s not just things called “capacitors” that are capacitors:  Electrostatic speakers, like Quads, Martin-Logans, my own favorite, Acoustats, and others are capacitors, too. (The stator(s) [fixed grid(s)] and the moving diaphragm are the “plates”, which are separated by an air dielectric.) And so are all of the cables, both power and signal-carrying, throughout your system.

Where this is significant is that, in our hobby, where debate among audiophiles is often about not just which component or other system element is better, but about whether it makes any difference at all, cables are among the most hotly argued items.

Ears, Measurement And The “Placebo Effect”

Many (including me) believe that they obviously do make a difference and urge us just to use our ears to decide for ourselves. Others, citing “placebo effect” and other such psychological phenomena as support, declare that hearing, unless it’s under “double-blind” conditions, is not to be trusted and claim that, unless something can be measured, it simply doesn’t exist.

The engineering-types among those latter usually contend that the ONLY things that can affect the performance of a cable (and thus the sound of the system that it’s a part of) are resistance (R), capacitance (C), inductance (L), and the characteristic impedance (Z0) that arises as a result of them. The possibility of influence by any other factor seems to be rejected by them entirely.

What they neglect to realize in doing that is that capacitance, while similar to resistance and inductance in that it is affected by materials, quantity, and spatial (distance) considerations in determining its gross value, also has a strong time component to its effect, which the others, in themselves, do not:  Different dielectric materials not only have different dielectric constants (how much energy they can store per volume of material), but they are also different in the rates at which they can take-on and release stored energy.

Because this energy, once stored, is released back into the signal path out of phase with the incoming signal, either canceling incoming increments of signal or creating out-of-phase discharge artifacts, this is hugely important and is, in itself, proof that cables or any other capacitor in your system can make a difference to its sound.

Different Capacitors Sound Different. Do Cables?

When electronics designers—whether tube or solid state—create a circuit, they not only specify the value of the capacitors to be included, they also specify their type  and dielectric (film and foil, ceramic, tantalum, polypropylene, polystyrene, oil-filled, etc.). That’s because capacitors of different construction, even if of the same value, sound different.

Different capacitors sound different. So do different electrostatic speakers. Why should cables NOT sound different? Once you take time domain effects into consideration and their ability to cause phase shift and the cancellation or addition of signal elements, it would seem to take magic for them NOT to!

Building a New System: Where to Start?

Are you going to put together a new High-End audio system? Start with the cables! Read on to find out why this can give you better sound and save you thousands of dollars, now and in the future.

“The Best In The World”

My name is Roger Skoff. I am a cable designer, and, after selling my former company, XLO, some years ago, I have a new company (named RSX Technologies) that I am in the process of founding, and our products are already being referred to as “The New Best in the World.” Before you immediately leap to conclusions though, and assume that what follows must just be an attempt to sell you something, let me tell you that, at least initially, RSX will have only a very limited line of products, NOT including either interconnects or speaker cables—the cables a person building a new system would most likely to need to buy.

I don’t have a dog in this particular fight, but I DO have inside knowledge that you can benefit from, so keep on reading.

Speakers and Cables: Designed By Experts?

The first thing to know about any system is that, of all of the components going into it, the two least likely to have been designed by an expert are the speakers and the cables:  Anyone at all, with any level of knowledge at all, can take any driver at all or any combination of drivers; put them into any box, or no box at all, with any crossover or no crossover at all; wire it together and hook it up to an amplifier and a signal source, and it will produce sound, and he will be able to declare himself a speaker designer.

Similarly, any person at all can take any two conductors—a 30 gauge Kynar insulated “hookup” wire, for example, and one of the support cables from the Golden Gate Bridge (or a bobby pin and a railroad track)—and arrange them to complete a circuit between one electronic component and another, and they will pass signal, and the person doing it can claim to be a cable designer.

Electronic Components: Designed By Experts!

So how does that matter? Well, consider this:  NO ONE can start hanging transistors, tubes, capacitors, resistors, switches, inductors, and various other electronic components together at random (probably not even that “infinite number of monkeys over an infinite period of time”) and have it turn into a usable amplifier, preamp, CD player, or other High-End audio device. In order to get any such thing to function at all, a person needs to have better than just a “pretty good” idea of what he’s doing or it simply won’t work!

That’s why the difference between the very best possible electronic device and the very worst one that functions may be less than the difference between the very best and worst speakers or cables. And with speakers, the problem is compounded (making your choice of speakers to buy even harder) by the fact that the room that it’s playing in can have an immense effect on the sound of a speaker, with the exact same speakers sounding completely different in different listening rooms or even in different parts of the same room. (Ask Norman Varney about this. He’s an expert on such things.)

So why start with cables? And do cables really make any difference at all?

Cables DO Make A Difference

Let’s take the second question first:  Yes, they do! Even though there’s on-going controversy about it on nearly every one of the Hi-Fi sites on the social media (and in the print media, as well), the fact of it is that, despite many of the engineers or engineers-manqué among us declaring that cables don’t affect a system’s sound, and saying that the only things about them that matter are resistance (R), capacitance (C), and inductance (L), the truth is that cables are—from a physics and field-theory standpoint—wildly complex, and it’s fiendishly difficult (and expensive) to get them to NOT have any effect on the signals they carry.

That’s why cables are so difficult to properly design; why they’re so important to the sound of your system; and why, in putting together a new system, cables are the place to start. (If, incidentally, you’re interested, you can see why engineers are so often wrong about wire by reading my article “Electrical Engineering and the High-End” in The Absolute Sound, March, 2015.)

The Job Of Cables

Unlike any other component of an audio system, cables’ only job is to carry the signal from one place (a preamp, for example) to another (an amplifier). In doing so, anything at all that they do to it, other than to simply pass it along, is problematic:  If there are signal losses, that’s bad—they’re not letting you hear all of the exquisite detail that’s on the recording and that you have paid so much to buy great components to reveal for you. If they add anything (like hum, noise, or capacitive discharge artifacts from poorly designed or selected dielectrics [the cable’s insulation]) they’re also keeping you from enjoying your music to its full extent and, again, keeping you from hearing all and only the performance of the other gear that you’ve spent (or will spend) so much to buy. Similarly, any change at all to the signal—from its source (the phono cartridge, CD player, tuner, streaming device, or whatever else), all the way through to the speakers, is distortion and, if the cables are contributing any part of it, they’re not properly doing their job.

Cables Should Be Neutral

What you need cables to be is “neutral”—to neither add nor subtract anything from the signal they carry, and to not change it in any way in the process. And, if you can find some that are (or that you can afford, and that even come close) buy them; they’re the perfect first purchase for your system.

The reason for this is that no matter which part of any system you’re auditioning, you’re not just listening to that one thing: You can’t hear a speaker without cables, an amplifier or receiver, and a source component. Neither can you listen to any other part without all of the others. That’s why a system is called a system: It’s an agglomeration of parts, all of which are necessary to play the music and create the sound you want to hear. And all of it must eventually go through cables at one or more points along the way.

That’s why cable neutrality is important, and why the critics may be absolutely wrong when they describe a cable as “system dependent.” What they mean by that is that usually a cable will seem to change the sound of the system it’s plugged into, and that it will sound different on different systems. That’s not bad; that’s GOOD! Just as, if you pour chocolate syrup all over everything you eat, everything will taste of chocolate, so will a cable that’s “colored” (has a distinct sound of its own) make every system it’s used in sound the same. What you want is NOT that, but the cables that, when you try them on a dozen different systems, the systems have a dozen different “sounds.”

Audition Cables

And that’s exactly how you can find out which cables are the most neutral:  Get hold of a bunch of different cables, and try each one out on as many different systems as you can. The cable that sounds the most different on the greatest number of systems is the one that’s the most neutral and is the one that you should buy.

Once you’ve got your cables, you can then go into your dealer’s demonstration room and, using them, listen to all of the other components that you need, knowing that you’re hearing those components, to the greatest degree possible, exactly as they really sound.

All Demo Systems Are Not Equal

Beware, though, if the dealer has set his demo system up with a “dark” sounding “Thing A” and a neutral sounding “Thing B”, connected by a “bright” sounding cable, (or any other mix of components where the flaws of one thing are used to cancel out the flaws of another). Adding a neutral sounding cable to a system like that will actually make the system sound WORSE when you put in the more neutral sounding cable. That’s one reason, just in itself, why you should always try cables on as many systems as possible.

If you do that, and if you actually do find neutral sounding cables, and buy them and use them as the basis for your own system, you’ll not only have a better sounding system, that gives you a more accurate presentation of the glories of the music, the sound of your other components, and the interaction of them with your listening room but, when you later buy other components or speakers to upgrade your original system, you won’t have to spend more money on cables. The ones you’ve got will already be neutral and, except to buy some that might be even more neutral, you won’t have to buy any cables at all. You can either keep your cable money in your pocket or spend it on better other components or on improving the acoustics of your listening room.

Start with the cables; it makes good sense and it makes good sound!