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There are many categories of audio products, each designed for a particular purpose. High-end audio is a category of products that are typically designed for high fidelity audio reproduction. This is typically achieved with a no compromise design and manufacturing approach. Typically, the more we seek “convenience” , the more we try to make product “cheaper”, the result will be products that compromises “fidelity” of audio reproduction. When fidelity is compromised, listening to music might not be very engaging and the movie experience might not be as immersive as the movie directors intended.
The challenge for high-end audio products is to reproduce all nuances of an audio recording, with no added colour or distortion. This is also the reason why alternatively use the term “high-fidelity”.
Why is this a challenge ? We are trying to reproduce nature and human spirt from recorded media. Of course, like you would have guessed, we will soon run into the limitation of audio technology.
The diagram below illustrates the stack of technology required to record and reproduce audio. We achieve the most optimal audio reproduction only when all the stages are of highest quality. However, this article will only focus on the technology associated with reproduction. Recording and related topic will not be in scope, probably a future article.
Designers of high-end audio products assume – we cannot measure every aspect of audio reproduction. We believe science has not developed enough to reproduce nature in all its glory.
There are a few engineering phenomena that yield good sonics, but they are hard to explain in absolute scientific terms. Few examples would be the use of vacuum tubes, differences observed with cables, use of a certain type of film capacitors, vibration isolation of electronics and much more.
At the same time, measuring for lower distortions, controlling group delays, uniform impedance across frequency spectrum, etc., are examples of a few technical parameters that are in the realm of known audio engineering science. These measurements continue to play the most significant role in any audio product design.
So eventually, audio engineering involves a combination of known scientific technique and subjective analysis of technology choices. At Acoustic Portrait, we try to keep the subjective choices as minimal as possible and so do most of our colleagues in the industry.
Before any program, musicians tune their instrument for pitch. This tuning might not be obvious to our conscious hearing. However, without it, we will not enjoy the musical performance.
The answer lies in how we “experience” music, not just hear. When we listen to music, we use our aural senses and complex cognitive abilities.
There is a conscious part to this cognitive process. But there is a subconscious element. This plays a significant role when we listen to music or watch a movie.
This is part of a study called ” psycho-acoustics“. This study originally lead to the discovery of “stereo”. Further, “surround sound” is just an extension of the stereo.
Within the boundaries of known science, hi-end audio products pack the most sophisticated set of technologies for achieving the best audio reproduction. It is important to note; the emphasis is on purity and high fidelity.
Reproducing all the frequencies from 20Hz to 20kHz is relatively a simpler task. However, reproducing all these frequencies with the least distortion is harder. It is even more arduous to reproduce all the details, nuances and subtle sounds that we hear in nature.
We will categorize the technical objective of audio reproduction into three parts – distortion, dynamic range & dynamic resolution. If we get a good balance of these critical aspects, many other audiophile qualities will automatically come into place.
Distortions are caused at various levels and it is important to keep them under check.
- Distortions at each equipment level is generally minimal and published as part of the product specification.
- When we connect different equipment, distortions might be introduced due to factors like impedance, damping factor, EM interference, etc.,
- Further the room acoustics add a flavour of distortion as well
Distortion figures like THD, SNR, etc, are quite common in the specification of audio products across all categories.
There are few more distortions like group/phase delays, non linear frequency response, clipping, etc., that audio equipment manufacturers take into consideration during and manufacturing process.
The music CD format (PCM) comes with 16 bit depth, which limits the dynamic range to about 96db. However, today’s high end equipment can decode 24 bit formats and support upwards of 130+db of dynamic range.
Most recordings use different musical instruments that produce sounds of different loudness. The dynamic range of your system is an important quality that will help in reproducing the range of sounds produced by all these musical instruments.
For home theatres, this becomes even more important as the sound we are trying to reproduce all kinds of sound we hear in real life.
This is the ability of the system that lets you hear and perceive the difference between a 56db and 58db level. This is equivalent to high resolution in video. From our experience, this is perhaps the most important quality in recreating the emotion of a musical performance in your listening room.
Dynamic resolution is critical to achieve instrument separation and hear all nuances of performance by skilled musicians. For example, when you get better resolution, you will hear a more nuanced performance – even from a song that you are very familiar with.
Further movies often come with dense soundtracks. The increased resolution will clearly distinguish the various sounds to make the soundstage more realistic.
Apart from the technical aspects, we also need to consider the subjective aspects of audio reproduction. Because of the limitation of audio technologies, this becomes unavoidable. The responsibility falls on the designer to make careful design choices and optimize the final audio reproduction.
So it is important the designers are aware of these technology limitations, appreciate how people react to audio reproduction, and prioritize the nuances of creation by musicians and movie directors.
All this knowledge, combined with experience in designing electronics for hi-end audio, are critical ingredient for hi-end audio equipment. The designers gain these skills through many years of committed research into audio reproduction, taking into consideration the complexities discussed in this article.
The way we experience music or movie, is far more complex than just “hearing” some frequencies.
The combined aural and cognitive abilities allow us to detect and experience even the most nuanced aspects of audio reproduction. If anyone says they have less sensitive hearing or cannot connect with music, it only means they are yet to discover thier own potential.
To match with the incredible human’s cognitive capability, high-fidelity audio products need to be sophisticated as well. Manufacturers build high-end audio equipment with the best available technology, highest grade of electronic component and stringent manufacturing process in order to match with nature as much as possible.
If you have any queries, please do book a free audio consulting from acoustic portrait.