How to design the acoustic scheme of small and medium stadiums?


To a certain extent, sports is a product of social and economic development and an increase in people’s life needs. With the strengthening of my country’s national strength and the continuous improvement of people’s material and cultural living standards, many cities in China are building or preparing to build stadiums. Scales are basically practical, multi-functional or even simple, and they are all small and medium-sized stadiums. .

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We must pay attention to the construction of these small and medium-sized gymnasiums and carry out correct technical specifications and guidance. This article focuses on the basic knowledge and design methods of acoustic design of domestic small and medium-sized stadiums, analyzes the advantages and disadvantages of different sound reinforcement methods, and proposes solutions.
Acoustic environment

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The basic structure of small and medium-sized gymnasiums is divided into three types: open, semi-open and closed. Usually, there are no function rooms under the seats called open stadiums. The gymnasium is divided into a multifunctional gymnasium and a special gymnasium. Most gymnasiums in our country are multi-functional gymnasiums, suitable for holding various sports competitions and ordinary theatrical performances.

Special sports fields are designed and constructed according to the characteristics of certain sports, and are only suitable for specific sports games such as football fields and tennis courts.

Stadium acoustic environment requirements

(1) Special architectural acoustic design, design and noise control design should be carried out for stadiums.

(2) There is sufficient sound level in the auditorium to meet the necessary functions and requirements of the stadium.

(3) The sound reinforcement of the gymnasium should consider reducing the sound interference outside the gymnasium.

(4) The sound reinforcement equipment should have the characteristics of safe structure, convenient operation, convenient maintenance, windproof and rainproof, and reliable performance.

(5) The sound reinforcement control room should be equipped with an observation window, and ensure that the tuner can well watch the podium, referee’s stand, playing field and auditorium when it is working.

Basic direction and structure

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In China, the direction of small and medium-sized gymnasiums is usually similar to the north-south direction of the railway station, that is, the podium is located in front of the auditorium on the north side of the gymnasium and requires all-weather lighting. The disadvantage on the right is that the difference between light and backlight will be used in games such as football, which is not conducive to fair competition.
Due to the limitation of the venue, there are also those facing west and east, that is, the podium is located at the front of the auditorium on the west side of the stadium. This direction does not meet the requirements of all-weather lighting, and the advantage is that there is no front light and backlight for football and other sports games. Differences are conducive to fair competition.
The auditorium around the stadium is a saddle-shaped structure. For stadiums facing north and south, the podium is located in the middle of the Taipei side. There are approximately 32-35 seats in the North Stand, approximately 32-35 seats in the South Stand, and approximately 20 seats in the East Stand. The auditorium is located behind the south stand. The torch stand is located on the east side of the podium, the timing and score board is located on the west side of the podium, and the west stand also has about 20 seats. For gymnasiums located in the east and west, simply rotate the basic direction of the north and south gymnasiums counterclockwise by 90° to obtain the basic layout of the gymnasium and the routes for the opening and closing ceremonies.

Existing problems and solutions

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The common main problems in the acoustic design of small and medium-sized gymnasiums are: severe multiple echoes, severe sound overflow (disturbing people), more local quiet areas (sound dead zones), etc., which need to be coordinated with sound structure and electroacoustic design solve.

The solution to the multiple echo problem can be implemented from two aspects:

1. As far as sound structure design is concerned, it is necessary to increase some absorption and reflection surfaces between sound, shorten the propagation distance of sound in space as much as possible, improve sound absorption efficiency, reduce reflected sound energy, and avoid multiple reflections of sound . High-energy sound waves. Extend the reverberation radius.

2. Starting from the electroacoustic design, choose speakers with a large directivity factor (Q value) and narrow directivity, such as Q﹥15, with a horizontal directivity of 60°~90°, or even 40°~20°, 40° The attenuation slope outside the passband of ~20° is larger than that of 60°~90°, and the sound energy outside the passband is relatively lower.

It is also necessary to correctly design and adjust the coverage area of ​​the speakers, and control the width of the low-frequency sound bandwidth, which can also receive some effects. Note that the narrower the directivity of the speaker, the higher the cost, and there must be a comprehensive choice.

To solve the problem of serious sound overflow (disturbing the people), in addition to increasing the sound insulation settings, it is necessary to correctly design and adjust the direction and coverage of the speakers to reduce the sound overflow and disturb the people. Also choose speakers with a large directivity factor (Q value) and a narrow coverage angle.

The problem of local quiet zone (sound dead zone) can be solved by using low-power dispersive speakers and supplementary sound. There are also problems worth noting in the acoustic design of small and medium-sized stadiums: if there are more structures and walls such as ellipse or arc with large long and short axis, circle or arc with large diameter, large column, whispering wall, etc. It is easy to bring about the effects of sound focusing and crawling, causing serious sound defects, destroying sound quality, and reducing speech clarity. To some extent, this is a contradiction between styling design and aesthetic design. In the design process, we must pay close attention to the relationship between the two.

Guangzhou Q&S Audio Co., Ltd focuses on professional audio engineering and has rich experience in acoustic design for small and medium-sized stadiums. Welcome to postmaster@peas-pa.com