High fidelity and realism

Sound recording and reproduction became firmly established with the development of gramaphone in 1887. Ever since, enthusiasts have talked about fidelity or faithfulness of sound reproduction made possible by every technological advance. High fidelity is used to describe the most realistic sound reproduction obtainable; we can never expect complete fidelity to the original sound because our listening surroundings differ from those of the original. Unfortunately, the term hi-fi is often used to describe anything capable of producing a very loud sound regardless of its frequency range or the amount of distortion present. Thus, music and video as it is being delivered through the common mass market mediums available today produce more noise than reproducing the way the movie was shot by the cinematographer or the way it was recorded in a sound studio. The cheap electronics often introduces unwanted signals and also it distorts the original signal while trying to amplify the recorded signals, killing the charm of the music or movie. That is where hi-fidelity (true to original) systems make the difference. The degree of realism now attainable is very high, but so also is its cost! It is a matter for the listener to decide how far he is willing to go in this respect.

The problem can be simply illustrated by considering the dynamic range of music; let us take the case of an installation which has a dynamic range of 67 dB. If we wish to improve this to take into account peaks in orchestral works by increasing the capability to 70 dB, we require only 3dB extra. But 3dB increase means doubling the power. (the reason for this is that the ears respond logarithmically. Read more about decibels in this section) So if a 25W amplifier was in use to obtain a dynamic range of 67dB, increasing the dynamic range to 70dB will mean raising the output to 50W. So a higher power reproduction equipment for your dynamic range simply drives the cost up.!

Then there is the fad behind the terms analog and digital. Today every manufacturer makes believe quality connected with digital. But even in this digital era, analog systems and valve based systems which are supposed to be the purer analog sources are the most expensive! This is not to state that anything digital is bad. Let us see what is the difference in simple terms
The components that influence in enjoying quality music and video are

Analog - Any signal or sound wave source that our ears can appreciate is analog or a continuously varying wave. In nature sound is never in steps. Amplitude varies and frequency varies and that is how sound and sight is like. So conventional systems are all analog systems.

Digital - With the advent of computers anything digital has gained importance because that is what computers could crunch, compress or transmit etc without introducing noise. But that does not mean that it is true to original. By having high bit rate or sampling frequency, digital signals can match analog without really making it obvious to the listner that the sound is only a collection of the cut and joined pieces of the original sound or video source. Please see the illustration below to give an idea about what is the difference between an analog and digital signal which is that of the same source.

Fig.1	Fig. 2
	Consider this as a digital signal sampled quite closely to appear like the original, each sample being represented as binary numbers or hexadecimal by the PC to be processed and reconstructed.

In the above figure 2, if the sampling is even lesser, say by half, then instead of the 34 dots or hiphens that you see reduces. If it reduces to say 17 pieces by removing alternate hyphens, then you would see a signal which is lesser in quality and may not look like the original! This what you find as specificaton on many of your DVD systems who specify the sampling as 24 bits (representation of details of each dot or hyphen) and frequency of sampling (which is a measure of closeness of the digital to anlog) specified as 96 Khz. Etc

Audiophile applies more to music than theatre components and hence may be a more sound specific term. While evaluating any of the high end systems the non techie is also likely to confront terms such as THD, frequency spectrum, dolby digital, dts etc and get lost. Hifidemoroom has an update of such standards too. For a detailed reading please check our pages on standards and specifications or visit the links provided to the relevant websites.