The Art &
Science of Audio System Tuning
(Tone Painting for a Sonic Canvas), Part 1
by Mike VansEvers
(Editor's Note: Over the past year or so, I have had some very interesting conversations with Mike VansEvers, President of The VansEvers Company, concerning the tuning of audio systems. In the aftermath of our profile of the work of Michael Green, VansEvers and I agreed that his work would eventually be published in Positive Feedback.
The time has come. Mike's article covers some interesting ground, attempts to establish new terminology, and in conjunction with another article or two waiting in the wings here at PF Central should stimulate further discussion on the often controversial field of audiophile system tuning and "tweaking." Readers are invited to respond to Ye Olde Editor via email to firstname.lastname@example.org, or at the PF web site at www.positive-feedback.com, at our "Audio Tribe Boogie" discussion section.)
Conventional engineering is what people learn in school: its 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 dont 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 wed be happy listening to sine waves...or nothing. Some of us are quite content with a modest table radio, while others spend large amounts that would buy a nice home in an expensive neighborhood. At whatever 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 dealers, its 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 systems distribution of resonances, 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.
The purpose of this article is as follows:
1) To educate the individual as to how mechanical resonances are both a fundamental element and a major factor in the sound of all recording AND playback audio systems, and to show that resonances are not inherently "bad."
2) To point out how the distribution of these resonances the systems 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 audios 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 article 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 or more years had passed after Bayer began its manufacture...were our parents fooled into believing they felt better?)
THE REALITY OF RESONANCES
Mechanical resonances are a fact of life. Everything has mechanical resonances, from the Earth, to an audio components chassis, to wire. Removing ALL resonances 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 resonances, why would this be a bad idea? Because the resulting resonances would probably be restricted to the low frequency area, and wire reacts to mechanical resonances as if they were frequency-selective volume controls. In this special case, it means that only low frequencies would be emphasized, and if only one area is emphasized, then all areas are not being treated equally. When this happens, tonal neutrality is impossible.
CAN I HEAR THE EFFECT OF MECHANICAL RESONANCES?
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 tests 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: 1. You are an orderly person and there are 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 1.Listen to the first 30 seconds of the piece of music you have selected. Do this two or three times.
Step 2.Take a half dozen CD jewel cases, your car keys, and a dollars worth of change and place them all on the top of the CD player/transport.
Step 3.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 1.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 2.Take EVERYTHING off the top of the CD player/transport. Also take ALL jewel cases and non-essential paraphernalia off the equipment stand.
Step 3.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.
AN INSIGHT INTO THE EFFECTS OF RESONANCES
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 mechanical resonances 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 resonances 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 resonances; change the size, shape, and composition of a part, and its mechanical resonances 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 resonances will differ, and these resonances will electrically highlight different parts of the signals sonic spectrum, so the sound coming from your speakers will have to differ also.
This is a major reason and possibly the fundamental reason why todays conventional engineering practices alone are doomed to perpetuate the design and production of products that are a "Dr. Jeckyl" in one audio system, and a "Mr. Hyde" in another. The significance of an audio components resonances, 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 products "sound," designers cannot build nor can consumers buy a component that sounds accurate AND musical in any and all systems.
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.
"I THOUGHT ALL RESONANCES WERE BAD. ARENT THEY?"
A room consists of walls, a roof, and a floor. Because of this, rooms have audible resonances called "standing waves," which are unavoidable. All too often, an unfortunate ratio will exist between a rooms dimensions (length, width, and height.) This ratio will cause some bass frequency standing waves to exist in isolation with no nearby resonances. When this happens, some bass notes will sound much louder than other bass notes. (The softer bass notes will not have coincident room resonances to amplify them.) Very lumpy (ugly) bass will be the result. Fortunately, an acoustician can design a rooms dimensions so that these resonances will be evenly distributed. In this case, the contributions of the room resonances will be friendly in that all bass notes will be treated equally, and the bass will sound much better. This highlights the approach to which this article subscribes: resonances are unavoidable...make them friendly, not ugly.
(Unfortunately, most of us do not have the luxury of choosing our room dimensions, and the sound of our audio systems usually suffers. For more information about room resonances see Appendix A, useful articles and books.)
Todays engineering test methods are centered on electrical parameters that are almost as old as the telephone. They do not reveal information about a components mechanical resonances. Could these resonances cause a component to sound good "here" but not "there"? Yes.
While mechanical resonances contribute to the sound of everything in audio, these contributions are not always detrimental. Resonances are a fact of life...as is the asphalt used in our highways. And like asphalt and room resonances, mechanical resonances are annoying only if unevenly distributed. When too much asphalt accumulates in one spot, or not enough (bumps and potholes,) a drivers annoyance factor is increased; it is the same with resonances. Bunching and gaps in the distribution of an audio systems resonances, like those in a listening room, are quite audible and distracting; these discontinuities only increase a listeners annoyance factor.
The sum total of the resonances of every constituent part of an audio system (which includes the listening room and everything in it, as well as all electronic components and "accessories") is that systems resonance response. If a system with a reasonably flat frequency response also has a balanced resonance response, the system will sound "good." If the resonance response isnt balanced, this deficiency will be both audible and annoying. When a new components resonances make the resonance response of the system more even and balanced, the systems sound will become more even and balanced. In this case, the new components contribution will be judged to be positive. However, if the new components resonances "roughen-up" the systems resonance response, the sound of the system will also be "roughened-up," and this new contribution will be judged to be negative. This is one of the key mechanisms of "synergy."
AXIOM #2: The "Resonance Response" of an audio system is always a major factor in its musicality. The most musically neutral systems will have their resonances spread out evenly with no clumps or gaps in their distribution...just as the best listening rooms have an even distribution of standing waves. An even distribution of resonances establishes a level playing field for all of musics notes and overtones, allows the proper harmonic balance of the music to be preserved, and maximizes listening enjoyment.
Corollary No.1: No products are universal; just because a signal-path component or an "accessory" sounds good in one place, it does NOT mean it will sound good everywhere.
THE NATURE OF NEUTRALITY
Why arent products neutral right out of the box? Neutral in what system? With which CDs or albums? Solid state or tube? Class A or AB? Push-pull or single-ended? Audio systems are all different. Is the listener young, old, male, or female? There are real physiological hearing differences that will make the same piece hated or loved, depending on the age and gender of the listener. Neutral to a bass freak or to a detail freak? Unfortunately, in todays multi-dimensional reality, intrinsic neutrality is highly subjective, relative, and elusive.
Those who hold measurements in higher regard than listening experiences have a valid argument with regard to the variability of the human listening experience. Those who prefer to take advice from a skilled human-ear/brain combination have a solid position regarding the validity of pass/fail marks from a machine that cant tell Bach from Beatles.
To paraphrase an old saying: "neutral is as neutral does." Although conventional testing procedures were developed with the intent to insure the neutrality of audio components, arguments and verbal confrontations abound because many listeners feel that they have experienced this conundrum: better specifications often equal better sound. Their problem is with the word "often." Most audiophiles feel justified in their feelings of confusion (and maybe even "betrayal") because the word should be "always." This has created a distrust of specifications, a too-often-confused consumer, and an entire industry: tweaks. (The resulting de facto "working definition" for the word "neutral" is closer to an audio-specific definition of the word "transparent": a lack of gross colorations or other sonic aberrations which would hinder the ability to hear small differences in the sound of recorded media and other components in that system.)
Because of this confusion, this article introduces several new terms which have been coined in an attempt to resolve the problem. These new terms are utilized in a conceptual framework that attempts to unite the "perceived" with the "measured."
The first new term is actually a new label for describing the goal of conventional measurement techniques which have as their focus, measuring individual components (see Appendix B.) This goals new label: Static Neutrality. How well a component measures is the benchmark of its static neutrality. However, high levels of static neutrality have NOT historically correlated with high marks for perceived musicality.
The second new term is Dynamic Neutrality and is today only applicable to audio SYSTEMS. This term has to do with the distribution of mechanical and acoustical resonances in an audio system and how these resonances affect its perceived harmonic balance and neutrality. Unfortunately, test instruments other than the human ear do not as yet exist. (Or if they do, theyre very, very expensive, and are rarely found outside of a high-tech research lab.)
CANT GET THERE FROM HERE, TODAY...MAYBE TOMORROW
All acoustic and electric instruments are physically constructed from materials. These materials have mechanical resonances that will differ from instrument to instrument. These resonances will insure that each instrument, whether acoustic or electric, has its own individual sound. (Axiom #1 applied to instruments.)
As all stages of recording and playback equipment use wire or other conductors in their manufacture, the differing mechanical resonances of each stage (recording, mastering, and playback) will cause every stage to have its own individual sound, regardless of that stages static (measured) neutrality. (Axiom #1 applied to all stages of recording and play back equipment.)
In order to preserve the individual resonance signature of the instruments that are being recorded or played-back, the mechanical resonance signature of the recording, mastering, and playback systems would each have to be dynamically neutral (presuming that the measured (static) neutrality level is high.) To accomplish this, each stage would have a wide band resonance response consisting of evenly distributed, overlapping, low-Q resonances. This design philosophy is rarely understood and even more rarely implemented.
(High-Q resonances accentuate fewer notes and overtones than low-Q resonances, but the amount of accentuation will be much greater. This is especially problematic if these few notes/overtones had previously played only a minor role in that instruments harmonic structure. Low-Q resonances minimize the amplitude of these contributions and also cause less discrimination between one note and its neighbors, thus providing a more level support for all of musics notes and overtones.)
Audio equipment is supposed to be a "reproducer" of sound, not a "producer". Unfortunately, this is not true. Even if todays levels of static neutrality had achieved perfection, the lack of a scientific measuring stick for dynamic neutrality precludes the widespread advancement of audio equipment toward the goal of a truly neutral sonic reproduction of a live musical event.
GO YOUR OWN WAY
A manufacturer of camera equipment makes tools for a photographer to use in making photographs. A manufacturer of violins makes tools for a musician to use in making sound. In the same way, a manufacturer of audio equipment makes tools for the serious listener to use in making the-sound-of-a-system-playing-music. (A sonic-portrait?)
In order to make tools, it is necessary to use tools. The tools used to manufacture other tools include machinery, design philosophies, and measurement tools and techniques. The design philosophies determine the "what," and the measurement apparatus determine and establish verification of "how well." These production tools shape, and more importantly, define the resulting manufactured tools.
The production tools of the manufacturer and the serious listener differ in that design philosophies are only of passing interest to the serious listener. He or she will eagerly subscribe to any and all design philosophies (and even change them in "mid-stream") if more musical enjoyment is the result. Many (most?) designers/manufacturers have their design philosophies nailed firmly in place.
The measurement apparatus of the two also differ. The serious listeners apparatus is personal in nature: his or her ears and musical tastes. A manufacturer uses many measurements in an attempt to be universal. All tools used in the manufacturing of a product (including test methods,) act as fulcrums that determine the direction taken by that product. However, there are inevitable problems that must occur when using a set of measurements that does not include tests for a components resonance response. Because manufacturers are constrained with a limited set of "directions," they may not be able to "take you where you want to go." Achieving your sonic goals usually requires trying out products from many manufacturers...which can be defined as a guessing game.
Some manufacturers include subjective listening tests as a counterbalance to measurements. This is certainly a step in the right direction. However, it would be impossible for a manufacturer to conduct listening tests with all the possible combinations of equipment that could get used with its products.
The public, however, is not limited to a small number of combinations of components, and their goals are personal, not universal. That which will EXCITE one, will put another...to sleep.
The serious listeners goal of enjoying his music is quite a different goal from that of a designer or manufacturer: A manufacturer hopes to build a better tool; a serious listener hopes this tool can be used to smooth his path to musical enjoyment. Unfortunately, because of the limited scope of measuring tools available to manufacturers, listeners will have the ultimate responsibility for achieving maximum pleasure from their systems. Fortunately, tuning products abound, and this article will help listeners understand the necessity of a balanced resonance response, and apply the basics of tuning for the purpose of achieving balance in their personal (and unique) listening systems.
THE MISSING LINK
The concepts of accuracy and musicality can be seen as the basis for the two categories of neutrality. The history of audio componentry is peppered with instances of components that measure well but dont make the grade sonically, as well as components that measure poorly but are pleasant to listen to.
H. H. Scott was a manufacturer of tube components back in the 1950s and 60s. The chief engineer was Mr. von Recklenhausen. His most famous quotation goes something like this: "If a component measures good and sounds good, it is good. If a component sounds good but measures bad, youre measuring the wrong thing." To say that the wrong measurements have been made for decades would be to take the easy way out. It might be far more appropriate to say that in the absence of the "right" measurement, too much emphasis has been placed on the "wrong" measurement. While this "wrong" measurement is still an appropriate and valuable measurement to make, it is just not the most important measurement anymore. (The "wrong" measurement could be any of those used for measuring static neutrality. See Appendix B in part two of this article.)
The author hereby proposes a conceptual system that illustrates common ground between the "perceived" and the "measured." A Venn diagram is provided to make the mental leap less perilous:
Note: Areas 1-6 are subsets of the super set: All Audio Equipment.
Area 1: A.P.T.: This stands for Asymptotic Pure Tonality and is a goal for both systems and components. (Please note: This is not necessarily THE goal, but it is definitely A goal.) Once a product/system has achieved exceptional levels of measured performance (a high degree of static neutrality) as well as an evenly balanced resonance response (a high degree of dynamic neutrality,) its tonality will approach that of real life. However, nothing man-made is perfect, and we will always be approaching, but never reaching, the "Pure Tonality" of real life. (The definition of an "asymptote" is a straight line that continually gets closer and closer to a line with an infinitely extended curvature, but never intersects it.)
Area 2: High Degree of Static Neutrality: There are numerous tests and measurements based upon sine and square waves: distortion, phase shift, frequency response, slew rate, dispersion, signal-to-noise-ratio, and other measurements such as rise time. These tests are representative of conventional thinking on the possible distortion mechanisms of audio components. For a system/component to occupy this subset of the larger set "Accurate," most conventional tests must be passed at the highest levels possible.
Area 3: High Degree of Dynamic Neutrality: An even distribution of low-Q resonances, with few irregularities, is required for an audio system or component to reside in this subset of the set "Musical." At the present time, the test methodology relies on the human ear/brain combination.
Area 4: "Accurate": Systems and components that measure well in at least a few of the many conventional measurements reside in this group.
Area 5: "Musical": Systems and components that have a pleasant sound, rather than an "analytical" sound, reside here.
Area 6: Not Musical & Not Accurate: Plastic clock radios, many boom-boxes, and some rack systems.
It will not be possible to predict true sonic compatibility between components from a manufacturers "spec sheets," until a components resonance response is MEASURABLE and is utilized as an everyday design tool by all audio equipment manufacturers. Why? Because this readily audible but as yet unmeasureable quantity is always AS significant as the conventional quantities that are measurable (distortion, frequency response, output impedance, etc.) In fact, a components resonance response is quite often MORE sonically significant than any conventional quantity. Why? Because, as higher and higher levels of static neutrality are achieved, there will be less and less to cover up the sonic influences due to resonances (and other little understood phenomena.) An audio systems resonance response has become much more audibly significant than vanishingly small levels of distortion.
A TUNING RATIONALE
Products used to change the sound of an audio system, even though they arent actually IN the accepted audio signal path, are often called "tweaks." When you "tweak" an audio system, you are actually "tuning" it. The physical nature of every tuning product (tweak) mandates that the resonance response of any system it is used with must change; if it is to be put on, around, under, or over a piece of audio equipment, IT HAS TO CHANGE the RESONANT SIGNATURE of the SYSTEM. Because the resonances have changed, the tonality and therefore the sound of the system must also change.
Resonance tuning is a skill that you can learn. The first step is to trust your ears. You know what you like. The available arsenal for making your system sound better is really quite formidable. Cones, pucks, dots, oils, bricks, platforms, and a host of other tuning products are readily obtainable. A suitable selection should become a part of your audio toolbox. Care should be exercised, however: just as no one wrench can turn every bolt, no one tuning product can fix all sonic problems. Tuning products are tools that are handy when it and the problem match up; otherwise they just take up space. There are no bad tools, just inappropriate ones.
Cones, bricks, dots, pucks, jackets, discs, isolation platforms, etc. all change the resonant energy in audio components and accessories. These changes directly influence the harmonic balance and imaging of your audio system, thereby affecting your perspective on the music.
Tuning an audio system is like taking a saw, or other tool, to a piece of wood. The basic engineering of the wood is already done for you. All you have to do is to make it fit your own particular situation. The sound of your audio system is like that piece of wood.
WHY WOULD I WANT TO TUNE MY SYSTEM?
While most audio companies have achieved a high degree of Static Neutrality through use of conventional tests like THD and frequency response, other elements that are major contributors to dissonance have been overlooked until now and can cause a lack of synergy between high-tech components.
Non-signal-path products are the main focus of this article because their use will significantly alter the resonance response and thus the harmonic balance of your audio system. While signal-path products also alter the resonance response, they usually cost significantly more than most tuning products. This makes learning how to tune your system a cost effective approach for achieving musical satisfaction.
By learning some simple tuning techniques, audiophiles will be able to:
1. Realize high quality sound without wasting thousands of dollars. 2. Eliminate the frustrations caused from buying a "latest and greatest" product which isnt so great after all (at least for you...it may be for someone else.) 3. Bridge the gap between now and the time when a products measurements ARE an accurate guide to its compatibility with the rest of your system.
It is not necessary to completely understand or believe in these techniques in order to begin using them. Dont be afraid to experiment. These changes will be far easier to undo than trying to get back the old amp that your new amp was SUPPOSED to trash.
In addition to these practical considerations, there is also this artistic consideration:
Pictures taken from slightly different angles or offset in small increments of time will sometimes portray vast differences in meaning. In the same way, the sound of most musical artists material will vary from performance to performance. In part this results from the artistic interplay between the various musicians (as well as from varying acoustics and sound reinforcement elements.) This artistic interplay is the wellspring from which emotion and meaning are communicated to the audience. Because each artist brings a new perspective to each performance (sometimes the change is subtle, sometimes not,) his ability to communicate with the other band members and with the audience also changes on a day-to-day basis...sometimes for the better, sometimes for the worse.
Occasionally, it is refreshing to be able to achieve a new perspective on a piece of music that is very well known. With the tuning methods outlined in this article, changes can readily be made to an audio systems sonic perspective, which will enable the listener to derive new enjoyment from an "old friend." This is also an instance of artistic interplay and, as such, is as valid as any other aspect in the production and reproduction of recorded music. After all, this manipulation of perspective is the stock-in-trade of recording, mixing, and mastering engineers the world over.
WHAT IS TONE PAINTING?
Tone Painting is tuning with a twist; it is an approach that focuses on the audio system rather than the component or the tuning product; it is the antithesis of the standard operating procedure. The hot-new-whatever will sonically help some systems a little, and help some systems quite a bit. However, the hot-new-whatever will sonically HURT some systems a little, and significantly hurt other systems.
Tone Painting is the authors term for a system of tuning techniques and a rationale that came about because audio components and systems were seldom, if ever, sonically neutral. When tuning a system, i.e. adding and subtracting resonances, you are changing the systems tonality and harmonic balance...as well as its imaging specificity and soundstaging capabilities. Tonality is the starting point for all sonic qualities.
The-sound-of-an-audio-system-playing-a-piece-of-music is a sonic-portrait of that piece of music. The canvas for this music is your listening room, and its acoustic nature creates a sonic-canvas.
TONE PAINTING FOR A SONIC CANVAS
OUR GOAL: to increase our enjoyment level when listening to music. Our means are the application of Axioms 1 and 2.
Envision a three-legged table with a bowling ball balanced on its top. The bowling ball represents musical enjoyment. By keeping the ball at its highest level, i.e., off the floor, we achieve the maximum level of enjoyment with our system. The three legs represent the three major factors we have to balance in order to keep the tabletop level and the bowling ball off of the floor.
These three major factors are as follows:
1. The Room: Acousticians design recording studios utilizing scientific principles which allow them to design OUT many of the flaws that most of us have to live with in our listening rooms. Standing waves (room resonances) are an unavoidable consequence of having a roof, walls, and a floor. The dimensions of your listening room determine the distribution of its standing waves. Because most of our listening rooms arent designed by acousticians, our standing wave (room resonance) distribution will probably in no way resemble the ideal.
Because of this, the listening room is a MAJOR factor in the sound of our systems. The same system will sound different in different rooms. Just ask any died-in-the-wool audiophile who has moved. Equipment resonances that complemented the previous rooms resonance modes often conflict in the new room. In addition, power in different cities, or even different parts of the same city, cannot sound exactly the same. (See Appendix E in part two of this article.)
2. The Static Neutrality of the Components : The equipment we buy should utilize the highest level of engineering and technology that we can afford. Its true that superior specifications have not always been a key factor in the best sounding equipment. However, superior measured (static) neutrality can be sonically obscured by an irritating resonance response. (Its always best to compare apples to apples. For example, dont compare single-ended tube amp harmonic distortion specifications with those from a conventional solid state amp and expect to draw a valid conclusion.)
3. The Dynamic Neutrality of the System: There are thousands of manufacturers, brand names, and models of equipment; consequently, there are billions of possible combinations. The manufacturer that designed the equipment, the reviewer who wrote about it for your favorite magazine, and your dealer ALL have different systems. Each of these systems will sound different. Each systems owner will feel that he has THE correct idea about the sound of any given piece of equipment. However, your room, your mix of equipment, stands, cables, etc. WILL be different. If a particular piece of equipment makes the resonance response of your SYSTEM more even, you will probably like it. If not, you probably wont. This is because your ear will be drawn to the colorations caused by a more uneven resonance response, distracting you from enjoying the music. (These distractions can often be cured by re-tuning the system in order to even out the resonance response irregularities. This will increase the systems level of Dynamic Neutrality, produce a more pleasant sonic-portrait, and increase your level of enjoyment.)
(Mike VansEvers article will be continued in our next issue )
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