Evaluation of sound
Imagine reading sheet music, and Concert A has 440 Hz frequency. Two octaves higher would be 1760 Hz, and “Do, Re, Mi, Fa” would be so high as to be impossible to sing. The same is true with low frequencies. High and low frequencies are much less common than most of us think.
In evaluating sound, what one is grading is the correctness of music scale, instruments’ timbre, the singer’s voice.
The simplest way to evaluate whether a device plays correct sound is to turn up the volume. If a device (peripheral equipment, accessories) can produce pleasant sound at high volume without being noisy and causing listener fatigue, this indicates correct sound.
Listener fatigue is a phenomenon that can occur after prolonged exposure to auditory stimulus whereby sound becomes irritating and characterized by odd-order harmonic distortions. Good sound is natural, with minor distortion, well-balanced, with attack and resonance, width and depth, big soundstage, small S/N ratio, and fineness.
With the rapid advancement of transistor amplifiers since around 1972, the stereo system market has developed in a sales-oriented manner. Consequently, people have lost touch with live music, forgotten original sound and learned to enjoy altered, processed sound, all the while making sound evaluations without any knowledge about sound’s true nature.
A peak in the treble caused by distortion is very often mistaken for the continuation of a high-pitched sound. The ping of cymbals or vibrato of a violin could indeed be described as a peak of sound. However, sound that comes closer to the original does not strike at us but is surprisingly subtle. Some people believe that forwardness of sound is a virtue, and that nothing is wrong with accompanying instruments overpowering a singer’s voice. But this simply indicates an overtuned tweeter.
As mentioned before, there are not as many high-pitched sounds in sheet music as most people think. If you can distinguish the tweeter’s output, it most probably means that its broadcast is too strong. This is an indication of unnatural sound. The same is true of the low- and mid-ranges. People often mistake low-pitched sounds for continuing bass, and bright midrange for richness of sound.
Live concert hall music is not characterized by intensity of pitch. Accentuating low- and high-pitch sounds and reverberation are marketing strategies meant to create tremendous impact. Accurate sound is not altered, colored, or distorted. It is natural.
When testing audio equipment, always be sure to choose the right music genre (we suggest vocal music or live opera recordings). If the sound has excessive pitch, it is artificially balanced and colored.
Finding the right balance of sound requires a shift to prizing quality over volume, and quality does not necessitate loud bass and treble. Quality means that the scale of the notes is clear, and the instruments are playing their parts with correct tone.
Listening takes practice. With practice, sound evaluation becomes possible.