You might think that a science-based field like audio engineering would be immune to the kind of magical thinking we skeptics see in other fields. Unfortunately, you would be wrong. In my 35 years as a professional audio engineer and musician, I've seen some of the most outrageous pseudo-science sold to consumers, and even to other audio pros who should know better. Not unlike claims for alternative medicine, nonsense is shrouded in scientific-sounding jargon to confuse the uneducated. Or a sales pitch will cite science that is legitimate but irrelevant. The result is endless arguments among audiophiles over basic scientific principles that have been fully understood for fifty years or longer.
As a consumerist, it galls me to see people pay thousands of dollars for fancy looking wire that's no better than heavy lamp cord they can buy at any hardware store. Or magic isolation pads and little discs made from exotic hardwood that purport to "improve clarity and reduce listening fatigue," among other surprising claims. The number of scams based on ignorance of basic audio science grows every day. Surely some of these vendors know they're selling snake oil, but I'm certain that just as many believe their own hype. I'd respect these people more if I thought they knew they were conning people!
Few of us have unlimited budgets and must spend what funds we have wisely. Therefore, the purpose of this article is to help you distinguish truth from fiction, so you can determine what is and is not worthwhile. Experience has shown that it's futile to claim I know what someone else can or cannot hear. Therefore, I will relate only those things that matter to my experienced ears, and explain what makes sense from the perspective of science and logic. You don't need a college degree to understand the explanations that follow, though I'll assume you've played with a stereo receiver and CD player or cassette deck a few times. I'll begin by defining the four basic audio parameters. Then when I describe some common audiophile scams later on, you'll understand why they are scams.
AUDIO PARAMETERS DEFINED
Only four parameters are needed to define everything that matters for audio reproduction: Noise, frequency response, distortion, and time-based errors. Let's look at each of these in turn.
Noise is the background hiss you hear when you turn your receiver way up, and you can also hear it during quiet passages when playing open reel or cassette tapes. A close cousin is dynamic range, which defines the span (expressed in decibels) between the background noise and the loudest level possible before the onset of gross distortion. CDs and DVDs have a very large dynamic range, so any noise you may hear was either from the original analog tape, was added as a byproduct during production, or was present in the room and picked up by the microphones when the recording was first made.
Subsets of noise are AC power-related hum and buzz, electronic crackling, vinyl record clicks and pops, between-station radio noises, tape modulation noise, and the triboelectric cable effect. You're unlikely to notice tape modulation noise outside of a recording studio because it's specific to analog tape recorders, which are fast becoming obsolete, and usually hidden by the music itself. You can sometimes hear it if you listen carefully to a recording of a bass solo, where each note is accompanied by a "pfft" sound that disappears between the notes. The triboelectric effect is also called "handling noise" because it occurs when handling poorly made cables. I haven't seen a cable with this defect in about 20 years.
Frequency response is how uniformly a device responds over a range of frequencies. Errors are heard as too much or too little bass, midrange, or treble. For most people, the audible range extends from about 25 Hz at the low end, to just shy of 20 KHz at the high end. Even though many audiophiles believe it's important for audio equipment to respond to frequencies far beyond 20 KHz, in truth there is no need to reproduce ultrasonic content because nobody can hear it. Subsets of frequency response are physical microphonics, electronic ringing and oscillation, and acoustic ringing. These subsets are not necessary for consumers to understand, but they are important to design engineers and acousticians.
Distortion is the common word for the more technical term nonlinearity, and it adds new frequency components that were not present in the original source. When music passes through a device that adds distortion, new frequencies are created that may or may not be pleasing to the ear. The design goal for audio equipment is that all distortion be so low in level it can't be heard. I'll return later to the notion that distortion can be pleasing when I explain why some audiophiles prefer vinyl records and tube-based electronics.
There are two basic types of distortion - harmonic and intermodulation - and both are almost always present together. Harmonic distortion adds new frequencies that are musically related to the source. In layman terms, harmonic distortion adds a slightly thick or buzzy quality to music. All musical instruments create tones having harmonics, so a device whose distortion adds a little more merely changes the instrument's character by some amount. Electric guitar players use harmonic distortion - often lots of it - to turn a guitar's inherent plink-plink sound into a singing tone having great power and sustain.
