INFO SONXPLUS: What exactly is high fidelity?

This is the first in a series that will attempt to demystify the fascinating world of high-fidelity. My approach will be straightforward, using real-life examples to help explain the hows and whys of designing high-performance home audio equipment. High-fidelity is the first of the five pillars of successful audiophile listening: the integrity of sound reproduction.

My aim will be to make things easier to understand, while avoiding confusion, as too many people in my industry unfortunately do...

It's unfortunate that, to attract a potential audience or give themselves a more prestigious image, some people resort to excessive ornamentation and an overly sophisticated vocabulary, sometimes incomprehensible to the average person.

That said, I prefer science to rhetoric, so let's get on with the preamble!

In order to understand what happens when you listen to music, you need to know what the basis is.

It is well known that the art of music is made up of sounds that are highly nuanced from one another. It is therefore important to be able to capture these nuances as accurately as possible, but how?

When a device or loudspeaker reproduces music, the challenge is to reproduce the various aspects of that music as it is. Without these fine details, the artist's emotion simply won't reach the listener...

Firstly, what does the music consist of?

A) The note

It sets the tone for every orchestrated movement, and can be muted and low or high and sparkling, as well as the entire range between its two extremes.

B) Frequency and harmonic. 

Notes are defined by their fundamental and harmonic frequencies, while sounds sounds have two components that enable us to distinguish them: the fundamental and the harmonic.

The fundamental is the frequency at which the note vibrates, giving the tonality that determines its position on the scale from low to high. The harmonic is the accessory component of the note that gives it the distinctive timbre of the instrument. For example, when a musician plucks his bass guitar string, the drier sound that accompanies the note is made up of harmonics. Without harmonics, instruments would all sound the same, and human voices would all sound the same...

Guitars of all kinds, various sounds.

C) Stereo channels.

In the jargon of electronics, we hear about this or that "per channel". In fact, it's the left and right channels for listening to music.

Stereophonic sound, more commonly known as stereo, is a method of reproduction that creates a spatial effect. By differentiating between the sounds perceived on either side of the listener's head, it is possible to appreciate their origin and depth of field. To achieve this, the listener must be at the apex of an equilateral triangle formed by the listener and two loudspeakers placed at equal distances.

D) Spatial effect of stereo.

A sound effect that aims to reconstitute the spatial distribution of the original sources.

Under ideal conditions, the listener hears sounds as if in nature, or as if facing the orchestra at a concert. Accuracy of sound rendering is crucial, as it enables sounds to be distinguished from left to right and front to back. Higher-pitched sounds, rather than lower ones, require extreme finesse, as they contribute greatly to our ability to perceive spatial effects. 

E) Bass, Mid and High frequencies.

To put it plainly, depending on taste, some people prefer to pay attention to the bass to physically feel its effects, while others prefer the mid-range frequencies that comprise the human voice, as well as the majority of instruments' mid-range tones. For others, it will be to hear with distinction high-pitched sounds and the slightest instrumental harmonics, as well as the sparkle of cymbals and other fine percussion. The audiophile, on the other hand, will prefer accurate sound, but above all perfect, well-defined spatialization.

Devices usually offer the option of adjusting high and low tones, as well as other features, although more and more people are opting for unmodified listening.

More and more good amplifiers and loudspeakers maintain the integrity of the reproduced parts without difficulty, making any correction of low, medium or high timbre unnecessary.

Now that we know what constitutes music, we need to monitor the performance of our reproduction equipment. We will monitor :

1) Distortion.

Distortion is a departure from the original. When a device creates distortion, it changes the sounds in such a way as to make them less true to the source, sometimes it is hardly noticeable, while in more severe cases it is openly unpleasant.

This is not to be confused with the distortion used in electric instruments, such as the guitar, or that used for the voice, adding depth, reverberation or outright distorted vocal sound, as used by artist Billie Eilish. These modifications are deliberate and part of artistic expression.

Audiophiles are interested in three types of distortion: harmonic distortion, which modifies harmonics and affects timbre; intermodulation distortion, which causes phonological units from bass to treble to influence each other, resulting in a muddled sound. The third, known as linear distortion, occurs in the frequency response. Certain sounds will be either augmented or atrophied, resulting in an inaccurate reproduction of the emphasis given to each sound by the artist during mixing.

For the first two types, the measurement will be expressed as a percentage for a value that must be within a fraction of a percentage. The smaller the number, the better. The strict minimum should therefore be 0.1%, while for an audiophile, 0.05% or less should be sought. As for frequency response evaluation, this will be expressed in dB, or decibels, which represent the energy calculated by an algorithm, i.e. a deviation of plus or minus a certain number of dB.

 Let's simplify this! If we have a 2 dB variation across the whole range, there will be places where too much bass, or treble, or any other sound will be "boosted" or "muffled". The smaller the value, the better!

 Voilà!

2) Unwanted background noise.

Another challenge facing audiophile equipment: reproducing music, and only music.

Left to their own devices, electronic devices let through sound interference resembling hissing and buzzing. It is expressed in decibels and corresponds to the level of amplification at which this residual noise begins to be heard.

A ratio of minus one hundred decibels (-100 dB) means that in relation to a signal of reference intensity, it will have to be lowered by 100 dB before it becomes inaudible, having been "ratified" by the unwanted noise. Note that the decibels expressed here are of an energetic nature, according to a logarithmic formula. Not to be confused with sound pressure, also expressed in dB. At the end of the day, however, the lower the noise, the easier and more defined the hearing...

The higher the negative dB figure, the better. In fact, as well as being distracting, background noise will rob the amplifier of power and dynamism, as the amplifier works to push out these unwanted sounds in favor of the music itself. Only the music should be heard.

3) RMS power.

As well as having a timbre, music is dynamic, meaning that it constantly varies in amplitude. To keep up with music's fortissimo movements, we need reserves of power. This power is expressed in watts, which is a measure of the heat produced as a result of work. The greater the power released, the more heat or watts produced.

It is advisable to choose a more powerful device so that it can cope with the demand without being overloaded, which will lead to unwanted distortion.

For comfortable, uncompromising listening, i.e., to hear the softer passages loud enough to hear the more dynamic passages well without restricting them, will be the goal. 100 watts per channel will be a good start.

Power indicators on meter view.

Effective power won't tell the whole story, however, as reserve capacity will vary from one amplifier to another. To sort it all out, you'll need to make sure you understand the principles of construction and amplification, such as class "A", "B" or hybrid "AB", and finally "D", and so on. There will be a full article on the subject to come.

Simply put, don't think of the number of watts as a source of loudness, but rather as a reserve of energy to bring out all the nuances in your listening.

4) Watts vs Distortion.

Some manufacturers present the high power of their devices as an absolute. In fact, the advertised power is only important if it occurs at low distortion. In fact, the same amplifier can deliver 80 watts with a very low distortion of 0.002% (tones have a deviation of 2 thousandths of 1 percent), whereas if you push it to 110 watts, it will do so, but with a huge deviation of 10%. (Sounds like AM radio)

The manufacturer who advertises his products with a high power rating without worrying about the level of distortion is doing his customers a disservice...

Simply stated, what's the point of listening to it loud if it's not beautiful...

5) The damping factor.

An amplifier's damping factor is a value more rarely disclosed by manufacturers, and usually only in high-end products. When an amplifier induces a loudspeaker to react, the latter physically resists the requested movement. This resistance returns an opposite effect to the amplifier via its electrical wiring, thus altering fidelity. The loudspeaker's membrane won't follow the required movements, and fidelity is lost.

A high damping factor will guarantee better control of the loudspeaker, which must faithfully follow the movement required of it.

This denotes a certain quality of coercive force. For this, a good set will feature loudspeakers with powerful magnets, very rigid and non-resonant diaphragms, coupled to a powerful amplifier with a damping factor of 150 or more. 

The last word

I've just set the table for various future columns, as we'll soon be dealing with each of these features applicable to the various components. We'll see how fidelity reproduction is achieved technically, but I'll also identify the components and describe their usefulness. In particular, I'll focus on the loudspeakers, which are responsible for the success of the whole system. A few buying guides and manufacturer histories will be sprinkled here and there. So there's something for everyone! 

I hope you've enjoyed this, and I invite you to comment on any topics you'd like me to explore further.

March is audio month!

Come and see us at the show on March 28-29 and 30, 2025.

Stay tuned!

Christian.

PARADIGM PERSONA+ FOUNDER