Sound Engineers. Why Is It Hard to Work Together?

Sound Engineers. Why Is It Hard to Work Together

Today, there are many professional professionals in the field of sound engineering: acoustics, designers of sound systems, sound engineers with various specializations. They are experts in recording studios, cinema, theater, live sound (in the latter case, they are system engineers, FOH (Front Of House) directors, sound operators). We cannot but mention the developers, manufacturers of electroacoustics and other scientists. All of these people are united by sound – an interesting science that intersects with art. The art of arousing emotions, fascinating stories, creating impressions that go beyond the usual. Indeed, in addition to popular music, there are experimental genres that are able to surprise with an unusual atmosphere and unpredictable compositional twists. There is a separate direction – Audio Experience, which can hardly be called music. These are rather sounds that are difficult to describe, but listening to them gives a lot of experiences and impressions beyond the scope of our usual perception.

And yet, what is sound – science? Yes! Moreover, it’s quite old, because Mr. Harry F. Olson, doctor of science, described all the principles of acoustics, substantiating them with mathematical formulas, back in 1947 in a book called Elements of Acoustical Engineering. Since that time, only digital technologies have appeared that have added the ability to delay the signal and FIR (Finite Impulse Response) – filters to sound engineering. At the same time, new materials appeared in the technologies (fiberglass, carbon fiber, composite materials, neodymium magnets) but they did not make changes in physics. What then are the difficulties with this area if everything became clear with physics 68 years ago? Let’s try to figure it out.

  1. Sound is invisible;
  2. The sound is very unique. It can be heard exclusively at a specific point at a particular time. For comparison: light can be seen simultaneously in different places and constantly;
  3. We perceive sound pressure and frequencies on a logarithmic scale but we speak about it linearly;
  4. We speak of music as “soft,” “resilient,” “sharp,” “bright,” etc., but these words are not unambiguously related to objective parameters. And, nevertheless, we use them as expressive means;
  5. Sound is both science and art at the same time, and not one of its components can be ignored;
  6. Sound reinforcement systems are far from perfect. Air is the medium for transmitting sound waves from the speaker to the ear. With the change in temperature, humidity, wind and other environmental changes, we can not talk about stability;
  7. Our ears are amazing instruments, the difference between the threshold of hearing and the pain threshold is 32 trillion times in power. The ratio of the lowest and highest audible frequencies is 1000:1. Despite the unique properties of our hearing aid, it is subjective and adaptive, and it sometimes forgives us the grossest engineering mistakes made when designing and / or tuning a sound reinforcement system;
  8. Our electro-acoustic devices (loudspeakers) are quite limited in capabilities, they are capable of reproducing sound waves with a wavelength ratio between the longest and the shortest at 600:1, and the better the remaining indicators (maximum pressure, frequency response unevenness (amplitude-frequency characteristic –, the level of harmonics, etc.), the narrower the range of reproducible frequencies. Our technologies are advanced but far from perfect.

What to do? How to clarify this area? To get started, let’s draw a clear line between science and art. Phenomena that are explained by the laws of physics, such as, for example, sound pressure, the range of reproduced frequencies for a certain frequency response unevenness, frequency response unevenness (there are a finite number of distortion types), directivity of acoustic systems, etc. are objective parameters that can be measured and compared.

Despite the fact that our hearing aid also works according to the laws of physics, it is unique, adaptive and has various deviations for each person. Well, the way our brain interprets the information received from the hearing aid has not yet been fully studied, so by default, we will attribute this area to art. Engineers in Europe using objective evaluation criteria are actively developing methods for tuning systems that will create an effective way to obtain a repeatable result. To do this, you need:

  • understanding of the processes occurring in the system (physics);
  • clearly defined goal;
  • generally accepted methods of objective quality assessment;
  • understanding and ability to use system configuration tools.

European engineers work collectively, create communities for effective collaboration, for example, AES (Audio Engineering Society). Based on my personal experience working with rental companies, as well as on the experience of communicating with a large number of specialists (I conduct seminars on sound engineering), we dare to conclude that in some countries, unfortunately, such phenomena are extremely rare. And there are several reasons for this:

  • an understanding of the processes occurring in the system is at an intuitive level;
  • the goal that most engineers set for themselves is a subjectively good assessment of sound;
  • methods of objective assessment are absent or ineffective;
  • the main tool is a graphic equalizer.

A different understanding of the ongoing processes does not allow engineers to “speak the same language”, which excludes the possibility of exchange of experience. Subjective quality assessment refers to art, and any discussions on this topic cannot lead to constructive solutions. Methods of objective assessment often come down to measuring the frequency response of a smartphone at one point. Even if it is a measuring microphone, the question is the analysis of the frequency response, the method of measuring, averaging and interpretation of the results. Using a graphic equalizer is a very crude and inefficient way to improve the sound quality that came to us from the distant 70s. In cases where the goal is to achieve uniform coverage of the site, any correction using the graphic equalizer affects the entire area and does not solve the problem. Cutting out room resonances with the help of “graphics” does not solve the problem either. The most effective solution is the system design, in which an extremely small amount of acoustic energy is emitted to places that do not need coverage (walls, ceiling, and other areas). Directional arrays of low frequencies, the correct selection of the dispersion angles of the speakers and their correct location are a fundamental solution to the problem of compromise with room acoustics.

All this is just the tip of the iceberg. I have come across many absurd decisions made by both installers and distributors. The latter have less responsibility, as their work is one-time, for one event. The work of the installer is designed for its repeated use but projects that do not correspond to either logic or common sense are often found, and distributors have to work on these systems with a very deplorable result. Of course, they become “extreme”, which does not make them happy…

Fortunately, changing the situation is not so difficult, the only questions are education and the creation of methods and standards. Education will help specialists “speak the same language”, share experiences, work on complex tasks together and learn to understand each other much faster. The generally accepted methods of an objective quality assessment will make changes in the result of the work and in the conditions for tenders. Naturally, this is not entirely beneficial to fraudsters but competent companies will be in high demand. This is a long process, the duration of which is comparable to the work of generations in the industry, but better late than never. We have every opportunity. There is a positive experience of the USA and Europe, and there is modern foreign literature describing techniques that thoroughly answer the challenges of today. Therefore, we wish all specialists not to lose their childish curiosity and often ask a simple question: Why? After all, it is this question that drives progress and science.

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