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. Our approach will be simple in order to help, sometimes with real life examples, the how and why of designing high performance home audio equipment. High fidelity is the first of the five pillars of modern audiophile listening, the integrity of sound reproduction.

My aim will be to popularise while avoiding confusing the reader as unfortunately too many players in my industry do...

This is a good example of how, through excessive embellishment and the overuse of technical terms, some people try to win over potential customers or at least look better...

One manufacturer writes this:

"The crossovers require no parts because of the synergy between our custom drivers, but the components are the best in the world. Our crossovers are not built on PCBs because the laminated conductor circuits are weak and inconsistent. Instead, they are attached to a thin piece of fiberboard or insulated polymer, and the components are mechanically crimped together because the sound is simply better. When we have to solder, we choose pure silver WBT connectors.

All this to say:

Our speakers are well matched, we don't use solder, but joint connectors laid on a laminated plate (which is actually made of PCB-like materials) for Print Circuit Board which the manufacturer claims not to use... They also claim that PCB mounting (a universal circuit construction standard) is not accurate or stable. It sounds better, but if we have to solder, we use silver... (Not very scientific!)

That said, let's continue with this 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 emotion of the artist will simply not reach the listener...

Firstly, what does the music consist of?

The note

It sets the tone for every orchestrated movement, it can be dull and low or high and sparkling and the whole range in between.

Frequency and harmonic.

Fundamental and harmonic frequencies define notes, while sounds have two components that allow us to distinguish them: the fundamental and the harmonic.

The fundamental is the frequency at which the note vibrates, which gives the tone that determines the position on the scale. The overtone is the component that is incidental to the note and gives it the distinctive timbre of the instrument. For example, when a musician plucks a bass guitar string, the drier sound that accompanies the note is made of overtones. Without overtones, instruments would all sound the same and human voices would all sound the same...

Guitars of all kinds, various sounds.

The Stereo channels.

In the jargon of electronics we speak of this or that "per channel", we are in fact talking about the left and right channels for music listening.

Stereophonic sound, more commonly known as stereo, is a method of reproduction that allows for spatial effect. The differentiation between the sounds perceived on each side of the listener's head allows the listener to appreciate the source and depth of field.

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 they were in nature or as if they were in front of the orchestra at a concert. The accuracy of the sound rendering has a great influence here, as it is what makes it possible to discern what is coming from the left or the right and from the front to the back.

Bass, Mid and High

To put it plainly, depending on taste, some people prefer to pay attention to the bass in order to physically feel its effects, while others prefer the mid-range frequencies that comprise the human voice, as well as the majority of the instruments' middle tones. For others, it will be to hear with distinction the high tones of the smallest instrument harmonics as well as the twinkling of cymbals and other fine percussion.

The devices generally allow this to be adjusted, although more and more people prefer to listen as is without alteration.

More and more good devices and loudspeakers maintain the integrity of the reproduced material 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 :

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.

Two types of distortion are of concern to audiophiles, harmonic distortion which affects the timbre by altering the harmonics, and so-called intermodulation distortion which causes the single phonological units from low to high frequencies to influence each other resulting in a confused sound. Its measurement will be expressed as a percentage and the value should be within a fraction of a percentage. The smaller the number the better. The strict minimum should therefore be 0.1%, whereas for an audiophile, 0.05% or less should be sought....

Unwanted background noise.

Another challenge for the audiophile's equipment is to reproduce the music, and only the music.

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

A ratio of minus one hundred decibels (-100db) will mean that at 100 decibels of sound power, residual noise begins to affect performance.

The higher the number, the better. Indeed, 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 favour of the music itself.

Effective power.

In addition to timbre, music is dynamic, i.e. it varies in amplitude constantly. In order to keep up with the fortissimo movements of the music, we need power reserves. This power is expressed in watts, a measure of the heat produced as a result of work. The more power is released, the more heat or watts will be 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 well without restricting the more dynamic passages will be the goal. 100 watts per channel is a good start.

Power indicators on meter view.

The effective power will not tell the whole story however, as the reserve capacity will vary from one amplifier to another. To sort this out, you'll need to look at construction and amplification principles such as class "A", "B" or hybrids such as "D", etc. There will be a full article on the subject to come...

Watts vs Distortion.

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

The damping factor.

The damping factor of an amplifier, or "Damping factors"This is a value more rarely disclosed by manufacturers and usually only at the high end. When an amplifier induces a speaker to react, the speaker physically resists the requested movement. This resistance will return an opposite effect to the amp via its electrical wiring, thus altering the quality. The loudspeaker membrane will not follow the required movements and fidelity will be lost. A high damping factor will guarantee a better control of the loudspeaker, which will have to follow faithfully the movement that is asked of it. This denotes a certain quality of coercive force in a way...

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 the fidelity reproduction is achieved technically, but I'll also identify the components and describe their usefulness. I will also follow two buying guides with an undeniable quality/price ratio, one generalist high-fidelity and the other oriented towards listening for audiophiles seeking perfection at a reasonable price. In short, there will be something for everyone! 

I hope you have enjoyed this, and I invite you to comment on any topics you would like me to explore further.

March is audio month.

Stay tuned!

Christian. Focal Kanta.