The Art and Science of Audio System Tuning
Commentary
Mike Vans Evers
February 2000

Publisher's Notes: What a delight it is for me to bring to our pages the views of Mr. Mike Vans Evers, audiophile, tweakmaster, and consummate music lover with the reprint of his most interesting books. This first chapter, which discusses the art of "tuning" (with more chapters coming), hopefully, will capture your attention. Hopefully you too will find the following reading as amusing as I have. Mike’s ideas on how to "tune" a system through a variety of unconventional means is quite interesting to say the least.

But first a little on Mike Vans Evers himself…

Mike Vans Evers was born in the middle of the last century and has a life long devotion to music with a groove and things of an audio nature in general. He has a degree in geology, and although he has never seen a rock professionally, he appreciates their contribution to popular music. His background includes live sound reinforcement, studio engineering and producing, electronics repair and design (tube and solid-state), the design and sales of power conditioning products, as well as tone-balancing products for home, studio, and orchestral use.
--Clement Perry

"When a new audio component actually sounds as good in our homes as it did at the dealer's, it's often cause for celebration. However, for most audiophiles, synergy between audio components has been, and still is, more luck than design."

Conventional engineering is what people learn in school: it's the stuff you find in books. It is the science of design. Unconventional engineering is what you learn on the job--the functional or esthetic combinations that work...those that don't work. This is the art of design. In audio today, there exists a critical link between art and science, which is often neglected: the underrated, but absolutely essential, art of listening.

We choose to listen to music in order to experience the emotion that it conveys or instills in us...otherwise we'd be happy listening to sine waves...or nothing. Some of us are quite content with a modest table radio, while others spend enough to buy a nice home in an expensive neighborhood. At what ever financial level we wish to play, the ultimate goal for a music lover is to be swept away and enchanted by our favorite music. It is the job of our audio systems to provide the wings and the magic. When a new audio component actually sounds as good in our homes as it did at the dealer's, it's often cause for celebration. However, for most audiophiles, synergy between audio components has been, and still is, more luck than design.

Because audio electronics are rarely neutral, a whole new class of products has come into being: tweaks. While to some, the word "tweak" has much the same meaning as the word "voodoo," its usage is historical and the mechanism of its effect has a basis in science...even though its explanation may not.

All audio systems are the result of the following process: sound is turned into electricity, which is then turned back into sound. In this process, there are three types of energy that flow: signal, power, and mechanical vibrations. The third energy type, mechanical vibrations, affects the first two, signal, and power.

"Tuning" is the conscious and deliberate act of making these unavoidable mechanical vibrations affect our sound systems in a friendly way. The proper goal of tuning is to bring an audio system's distribution of resonance’s, its "resonant response," into balance. When this balance is achieved, an audio system will provide a more musically neutral interface between musician and listener, and in so doing maximize the emotional connection between the two.

Tuning can increase the magic of any listening system, from the humble table radio, to those with Rolls-Royce pedigrees and price tags.

"Tuning can increase the magic of any listening system, from the humble table radio, to those with Rolls-Royce pedigrees and price tags."

The purpose of this essay is as follows:

  1. To educate the individual as to how mechanical resonance’s are a fundamental element and thus a major factor in the sound of all recording AND playback audio systems...and to show that resonance’s are not inherently "bad."

  2. To point out how the distribution of these resonance’s--the system's Resonance Response--dictates the acceptance or rejection of new components.

  3. To point out that the tunable nature of all audio equipment, without a current scientific method to measure it, precludes audio's ability to exactly and perfectly recreate a live acoustic event...except as the rarefied result of serendipity.

  4. To separate the goals of equipment designers/manufacturers from those of the listener.

  5. To illustrate how the Resonance Response of an audio system is the missing-link between "accurate" and "musical," and point out the necessary pathway for ending the subjective vs. objective debate.

  6. To offer a contrast to the "me-too" lemming approach so commonly found in audio. This contrasting approach is a tuning methodology with flexible tuning techniques for music lovers and hobbyists who wish to improve their listening skills and increase the performance and musicality of their systems.

In addition, it is the profound hope of the author that this booklet will help serve as a wake-up call and as a plea to the academic community to PLEASE find a way to measure what many people can easily hear and manipulate: the resonance response of an audio system.

(Note: The scientific basis for the effectiveness of aspirin was not proven until 65 plus years had passed after Bayer began its manufacture...were our parents fooled into believing they felt better?)

Mechanical resonance’s are a fact. Everything has mechanical resonance’s, from the Earth, to your DNA, to an audio component's chassis, to wire. Removing ALL resonance’s from ANY piece of equipment is impractical...if not impossible. Suggestions such as "Fill it full of _____" ignore the fact that _____ could be extremely messy if it leaked out (such as a highly viscous liquid silicone), or make it impossible to fix if _____ was a solid (like epoxy). In any case, the new configuration would still have to have at least ONE resonant (and very dominant) frequency.

Even if it WERE possible to get rid of all but a few low frequency resonance’s, why would this be a bad idea? Because wire acts much more like a musical instrument than most people suspect. Instruments with only low frequency resonance’s are fine when part of an orchestra or band. But I suspect that few would find a band made up entirely of bass guitars that interesting.

Resonance’s have been misunderstood. They have been thrown into the pigeonhole labeled "distortions." However, they rightly belong with "frequencies" in that both the frequency response AND the resonance response of an audio system need to be reasonably flat and even. Why? Read on.

Can I Hear the Effect of Mechanical Resonance’s?

It depends on your listening skill and resolve.

Here is a quick test:

Let your system warm up for at least an hour beforehand if you want to maximize this test's validity. Pick a piece of music that has plenty of high frequencies in it--if possible something that is on the edge of being harsh or irritating. Here are two of many possible scenarios: one. You are an orderly person and there is no CD jewel cases piled atop your CD player/transport/stand. 2. You are casual, and jewel cases and other objects are in residence all over the equipment stand.

Test for scenario #1:

Step one. Listen to the first 30 seconds of the piece of music you have selected. Do this two or three times.

Step two. Take a half dozen CD jewel cases, your car keys, and a dollar's worth of change and place them all on the top of the CD player/transport.

Step three. Listen again. The upper harmonics will be enhanced. The system will sound brighter, and the music will probably be more irritating. Some will consider this difference to be insignificant and might not benefit at this time from continuing.

Test for scenario #2:

Step one. Listen two or three times to the first 30 seconds of the piece of music you have selected. (Make sure there are at least a half dozen jewel cases and other metallic/plastic objects to remove.)

Step two. Take EVERYTHING off the top of the CD player/transport. Also, take ALL jewel cases and non-essential paraphernalia off the equipment stand.

Step three. Listen again. The upper harmonics will be reduced. The system will sound duller and the music less irritating. Some will consider this difference to be insignificant and might not benefit at this time from continuing.

A flat frequency response is supposed to be a major prerequisite for system neutrality. Unfortunately, our ear/brain combination is so keen that a flat frequency response is just one of the many steps necessary for achieving a musically satisfying audio system.

AXIOM #1: Because of the tunneling effect and piezoelectric and triboelectric properties, wire is microphonic. As a result, energy from a mechanical resonance affects the flow of electrical energy through a conductor in such a way as to audibly emphasize the notes and overtones that coincide with the frequency of that resonance. If we change the way a conductor (wire or PC traces) vibrates and/or resonates, we change the way it sounds. Thus, in a sense, wire can be thought of as a "mechanical" tone control.

All resonance’s affect the tonality of the sound of your audio system, whether they are electrical or mechanical...or a combination of the two. The electrical properties that cause wire and PC board traces to become mechanical tone controls are today just coming into focus. All materials have mechanical resonance’s; change the size, shape, and composition of a part, and its mechanical resonance’s will change. Even when the circuit and parts stay the same, a prototype that is MADE differently from a production model will SOUND different. (This statement comes as the result of personal experience and from conversations with other manufacturers.) Why? Because materials such as the chassis and mounting hardware will differ, the mechanical resonance’s will differ, and these resonance’s will electrically highlight different parts of the signal's sonic spectrum, so the sound coming from your speakers will have to differ also.

All audio equipment can be tuned. Because it can be tuned, it then has properties like those of a musical instrument, and SHOULD BE CONSIDERED A MUSICAL INSTRUMENT. All musical instruments have a characteristic tone...so do all audio system components.

This is a major reason--and possibly the fundamental reason--why today's conventional engineering practices alone are doomed to perpetuate the design and production of products that are a "Dr. Jekyll" in one audio system, and a "Mr. Hyde" in another. The significance of an audio component's resonance’s, to both consumer and designer alike, is a hidden aspect that confounds and confuses those seeking to build a truly enjoyable system. It "confounds and confuses" because without an adequate understanding of how resonance affects a product's "sound," designers cannot build nor can consumers buy a component that sounds accurate AND musical in any and all systems.

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