Acoustic calculation and architectural acoustics

• Building a model in EASE 4.4
• Changes in the architecture of the room
• Selection of facing materials
• Distribution of acoustic systems
• Output of calculation results
• Correct placement of equipment for any acoustic characteristics of the hall allows you to get good quality of perception of various sounds: speech, music, noise. In the space of the spectators participating in the event, it is necessary to ensure the required volume, intelligibility and sound without distortion in the entire frequency range of the audio signal. For this purpose, we offer the service of professional acoustic calculation. It allows you to choose the facing material of the surfaces, speech intelligibility and the composition of the audio system.
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• Our company carries out electro-acoustic calculations for various objects: stadiums, swimming pools, tennis courts, other sports facilities, concert halls, restaurants, open areas, temples, halls for concerts and conferences. When calculating acoustics, specialists take into account the architectural features of the room and the specifics of the event held in it. The required optimum sound pressure level varies in cases of broadcasting announcer announcements, background music, a concert by a star or classical music.

When calculating sound equipment for a specific hall, an analysis of the room is carried out. Based on this, the optimal distribution of the sound field and the placement of speakers are selected. A plan, sections of the room, a description of the finishing materials of the ceiling and walls are used.
To order an acoustic calculation, you should provide the initial data indicating the overall dimensions of the site, the height of the ceiling, materials, the nature of the event. Drawings or sketches are provided. If necessary, the project contractor takes measurements on site.

When calculating the power of the acoustic system, the noise level is taken into account as one of the parameters. It depends on the number of people in the hall and their actions. Higher sound pressure is required on the dance floor. The distance of listeners from the sound signal sources is also important. They are placed in such a way as to ensure a uniform sound field for all spectator seats. If the room has balconies and a mezzanine, then delay lines are added for them and calculations are carried out for each zone together.

By using the company's service of calculating and selecting an acoustic system, you can organize high-quality sound transmission anywhere: in a restaurant, club or stadium. According to our calculations, our specialists also install the equipment and configure it.
 The basis for designing a sound system or a room sound system is an acoustic calculation. With the help of an acoustic calculation, you can understand which acoustic systems are best to choose for a given hall and how best to arrange them to ensure uniform sound distribution. With the help of sound calculations, it is also possible to agree with the customer in which zones the volume level of the sound signal should be changed to ensure the comfort of the audience. Another task that can be performed using acoustic calculations is the calculation of sound absorption, the selection of facing materials for the hall or room where the sound system will be installed, to ensure high-quality speech intelligibility and good perception of music.
The issue of acoustic treatment of various rooms is very relevant at the present time. With the advent of new models of sound recording and sound reproduction equipment, it has become mandatory.

Modern industry offers a huge selection of finishing materials with various frequency properties, which allows, if chosen correctly, to obtain the necessary frequency characteristics of cinema halls, recording studios, speech studios, concert halls, railway stations, airports, conference halls, night clubs and many others.

The choice of materials was made according to various criteria, including economic ones. Thus, it is possible to choose inexpensive materials, but at the same time all the requirements for the frequency characteristics of the room are met. The correctness of the choice of materials will be confirmed by calculating the frequency characteristics.

To create a model for acoustic calculation, all the dimensions of the hall are required. In the specialized EASE program, a 3D model of the hall is created - an exact copy, with all the dimensions, in which materials are selected based on the sound absorption coefficient to achieve the recommended reverberation time for a certain type of hall and its purpose.
The figure shows graphs for various halls:

1 - halls for oratorios and organ music;
2 - halls for symphonic music;
3 - halls for chamber music, opera halls;
4 - multi-purpose halls, halls of musical and drama theaters, sports halls;
5 - lecture halls, meeting halls, halls of drama theaters, cinema halls, passenger halls.
As soon as the recommended calculated reverberation time has reached the desired result, simulators of acoustic systems (loudspeakers) are installed in the hall model. Speaker simulator files are in the EASE acoustic calculation program database and are periodically updated. In the 3D model of the hall (room), you can distribute the speaker simulators as you like, for this, specialists use certain rules that must be followed for sounding halls and other rooms. As in reality, speaker systems can be installed on a base (for example: on the floor or on the stage), at a height (suspended speakers) and built into the ceiling or wall. When calculating, the program will issue several parameters by which you can form a favorable acoustic picture.

Sound pressure - calculation

This parameter describes the distribution of sound pressure over the area of ​​the spectator zone without taking into account reflections. The magnitude of unevenness: the difference between the maximum and minimum pressure values ​​​​characterizes the correctness of the use of speaker systems and their placement.

Consonant Loss Ratio

Consonant Loss Ratio or ARTICULATION LOSS is a graphical representation of the loss of consonant articulation in percent. This is an inverse criterion, 0% is the ideal parameter value, describing the absence of consonant loss; 100% is the worst parameter value, describing the complete loss of consonants.

Recommended evaluation values ​​in percent:

from 0% to 7% - the best result;

-from 7% to 11% - a good result;

-from 11% to 15% - a satisfactory result;

-above 15% - a bad result.

In acoustics, the term "intelligibility" means the ability to hear and correctly distinguish all phonemes, i.e. the constituent elements of language. Speech intelligibility is the most important parameter when assessing the quality of sound reproduction, and depends, above all, on the correct understanding of consonant letters. Reverberation and a high level of background noise distort speech intelligibility. The percentage of "lost" consonants gives an estimate of the intelligibility of the message and is designated ALCons. For an acoustic signal such as speech, which is extremely variable in time and with all kinds of environmental noise, a sufficiently high signal-to-noise ratio (at least 10 dB) contributes to the best perception of the message. Intelligibility decreases with increasing distance between the source and the listener up to the maximum distance. For greater distances, intelligibility remains constant, no matter what the distance to the listener, but depends on the reverberation time. Any position of the listener is characterized by a certain value of Alcons. Reducing this value is quite difficult, since it involves changing the geometry of the room and / or the materials in it.

Calculating the speech intelligibility coefficient

Speech intelligibility is estimated using the STI coefficient. This parameter is the main coefficient for assessing the sound quality of a music system. For different types of rooms or tasks, there are their own ranges within which the STI coefficient value must fit. The STI coefficient depends on all parameters: the size of the room, the range of the sound emitter, the noise level, the audience, the room lining, the reverberation time, the sound pressure level.

Recommended estimated values ​​for the transmission of fast speech (intelligibility):

from 0.6 to 1 - the best result;

from 0.45 to 0.6 - a good result;

from 0.3 to 0.45 - a satisfactory result;

from 0 to 0.3 - a bad result.

Coefficient of musical clarity.

Recommended estimated values ​​for the coefficient of musical clarity C80 in dB:

0 dB - for organ, romantic music;

+2 dB - for classical music, choir, church singing;

+4 dB - for pop. Music;

+6 dB - for rock and roll. Our company carries out professional acoustic calculations of any complexity, specialists who have completed training in the specialized EASE program have a certificate, which is issued at the AFMG training center in Berlin, which is confirmed by the certificate provided below:

Acoustic calculation of the room is necessary for the precise installation of acoustic systems in the hall. Acoustic calculation is also performed to optimize the acoustic properties of the room.