Resonant acoustics device


Created on 24.09.2019 22:51.

Last updated on 16.11.2020 21:21.

Author: Negodailov A.N ..

As is known from classical acoustics, an ideal secondary source of sound vibrations is a physical object that emits sound simultaneously in all directions, without frequency and phase distortions – the so-called “pulsating sphere”.

This idea has not received a real embodiment to this day, due to the purely physical impossibility of creating a spherical object with an ultra-light and, at the same time, a super-rigid surface of variable area.

Any other solution to the problem of secondary sound, from an engineering point of view, has a certain number of both advantages and disadvantages.

The currently widespread acoustic systems with frontal radiation of a sound wave have a significant drawback – the spatial distortion of the front of the sound wave.

Resonant acoustics devices (URA) represent one of the possible solutions to the problem according to the ideology of its creation. In a volumetric secondary radiator, which is a pair of reflecting surfaces, in one of which (or in both) an electro-acoustic transducer is located, a cylindrical sound wave is formed.

Thus, in the room in which listening takes place, in addition to a directed sound wave, a correct diffuse sound field is created, which is characteristic of natural sound sources and creates optimal conditions for human perception of sound.

In addition, when using re-reflected sound, a number of parasitic harmonics characteristic of any electroacoustic transducer are suppressed.

Resonant acoustics devices are designed for sounding any room and for music lovers who are not satisfied with the unnatural sound of conventional speakers.

Unlike traditional speakers, reproducing resonant acoustics is almost indistinguishable from live performance.

Full sound realism has been achieved thanks to the new concept of speaker design.

The design of the resonant acoustics device is based on the principle of a radiator – a “pulsating sphere”, built on the basis of a natural musical row, that is, a set of sounds in which all its constituent frequencies are related to each other as natural integers. In subjective perception, the sounds that make up the natural musical range are better perceived compared to the rest.

The resonant device acoustically differs from traditional ones by a combination of three main features:

Specially created non-linear frequency response

A comb-shaped frequency response is created in the URA without the use of any electrical or electromechanical filters. In this case, the local maxima of the frequency response correspond to the frequencies that form a natural sound row, and the local minima lie between them. Due to this, the amplification of the frequencies that determine the subjective quality of the musical sound signal is provided, overtones are formed that refer to the main tones according to the law of the natural sound range, and the dissonant components are suppressed.

And all this is due only to the design features of the proposed URA.

Directional diagram of the URA

Currently, there are some designs of circular loudspeaker systems, which are considered to have better sound quality due to the diffuseness of the sound field. This point of view is quite natural, since many natural sounds (including those created by classical and folk musical instruments) have a weakly pronounced direction of radiation.

We also adhere to this concept, and the design of the proposed URA provides the formation of a sound field with a directivity pattern close to spheroidal, which also allows the listener to relieve the listener from spatial dependence with high-quality sound perception.

Resonant nature of excitation and propagation of sound vibrations

Most modern speaker systems are of the compression type. In such systems, excess pressure is transferred to the human body, causing the sensation of “acoustic shock”. This leads to rapid fatigue when listening to music, and with prolonged exposure (for example, among employees of discos, pop music performers) it contributes to the development of occupational diseases.

In URA, a different principle is used. Each frequency that makes up a natural musical sequence corresponds to a virtual acoustic resonator, which excites vibrations in the environment, which are transmitted to the listener, forming a complete musical picture.

It is known that not a single electro-acoustic transducer, no matter how high-class it is, is capable of reproducing a sound picture with high accuracy. URA is capable of forcibly displacing the remaining unsuppressed parasitic harmonics in accordance with the natural musical range, which will allow them not to be perceived as an annoying hindrance to hearing.

Medical aspects of using a resonant acoustics device

Despite a number of positive reviews from leading experts, the subjective quality of perception of the music reproduced by the proposed URA would be a weak argument in its favor, if it were not confirmed by the results of biomedical experiments. In 1992-1995 leading biophysicists of Russia conducted a series of experiments, the results of which showed a unique positive effect of the reproduced proposed device of resonant acoustics of music on the human body. In particular, the following were identified:

  • an increase in the alpha rhythm by 46% in all areas of the cerebral cortex;
  • increase in bilateral asymmetry by 12%;
  • an increase in the frontal-occipital gradient by 17%;
  • an increase in the physiological lability of the brain by 33%;
  • decrease in heart rate by 10%;
  • decrease in the number of functional extrasystoles by 3 times;
  • an increase in the number of compensatory pauses by 50%;
  • decrease in the variance of interpulse intervals by 2 times.

Traditional acoustic systems, even with the use of specialized music programs (music for meditation and relaxation), have a much less positive effect on the human body, and in some parameters even a negative effect was noted.

When working with the URA, a significant increase in the listening comfort before signs of fatigue was observed compared to traditional systems.

Design solution

A variant of the speaker case made of synthetic granite. The upper part of the body can be made of a translucent material and have an additional lighting function.
Option for a small hall

The use of URA allows you to create sound fields that provide high fidelity and high-end listening comfort.

The design features of the URA make it possible to widely use new design solutions to create models adapted for sounding various rooms – from …