1. Overview:

1.1 as a building for sports competition, sports teaching, sports entertainment, physical exercise and other activities, sports building is the infrastructure of sports;

1.2 the sound quality design of sports buildings should create a good competition and training environment for athletes, a safe and good audio-visual environment for spectators, and a convenient and effective working environment for staff;

1.3 sports buildings can be divided into "field" and "Hall", and "Hall" can also be divided into "comprehensive" and "single". The sports buildings with the stadium in the open air are called "field", the buildings with the stadium in the closed space are called "Hall", which can carry out various sports events, and the large-scale mass cultural and entertainment activities such as acting and meeting are called "comprehensive hall", which can only hold single sports events And the training hall is called the single gymnasium, also known as the special gymnasium. The sound quality design requirements of "field" and "special hall" are relatively simple, as long as a certain language clarity is ensured, without sound quality defects and noise interference, while the sound quality design requirements of multi-functional Gymnasium (Comprehensive Hall) are high, and the design is difficult, not only to control the reverberation time of the hall and prevent possible sound quality defects, but also to ensure that there is enough sound pressure level in the hall.

Therefore, this chapter focuses on the sound quality design of multi-functional gymnasium, and then puts forward the key points and key measures of sound quality design according to the field and Library Classification.

2. Sound quality design of multifunctional Gymnasium:

2.1 sound quality design requirements:

2.1.1 the sound quality design of the gymnasium shall start from the architectural scheme design stage, and the sound construction design, sound reinforcement design and noise control design shall be carried out in coordination and synchronization.

2.1.2 the sound quality design index of gymnasium shall be determined according to the grade, scale, use and use characteristics, and its main use function, and the corresponding measures to achieve the predetermined index shall be adopted in the design.

2.1.3 the sound quality design scheme shall take the natural sound source and amplifying speaker as the main sound source when dealing with the problems of sound absorption, reflection and avoiding sound quality defects in the competition hall, in combination with the requirements of building structure form, the configuration of auditorium and competition site, speaker setting, fire prevention, moisture resistance, etc.

2.1.4 the noise in the field shall be controlled within the specified background noise limit.

2.2 sound quality design procedure and method of Gymnasium:

2.2.1 determine the sound quality index:

Reverberation time: the reverberation time of the competition hall of the comprehensive gymnasium at 500Hz ~ 1000Hz shall adopt the indicators specified in the following table:

Competition hall volume (M3) < 40000 80000 = "" > 80000

Reverberation time (s) 1.2 ~ 1.4 1.3 ~ 1.6 1.5 ~ 1.9

Frequency characteristics: the ratio of the reverberation time of each frequency corresponding to the reverberation time of 500Hz ~ 1000Hz shall adopt the indexes specified in the following table:

Frequency 125 250 2000 4000

Ratio 1.0 ~ 1.3 1.0 ~ 1.15 0.9 ~ 1.0 0.8 ~ 1.0

Background noise limit: the noise control design of the competition hall and related rooms shall take measures from the aspects of general design, plane layout, sound insulation, absorption, noise elimination, vibration isolation, etc. the background noise shall not exceed the background noise limit in the table below.

Noise limits of different levels of halls and rooms in Gymnasium

Super, class A, class B, class C

Competition hall nr-35 nr-40

VIP lounge nr-30 nr-35

Sound reinforcement control room nr-35 nr-40

Commentator room nr-30 nr-30

Sound reinforcement studio nr-30 nr-30

2.2.2 clear use function

In the previous section, we have introduced that multi-functional gymnasiums should not only meet the functions of sports events and training, but also meet the functions of artistic performances, large gatherings, acrobatics, etc. in terms of sound quality design, it is impossible to achieve the best results of various functions at the same time. (there is only one kind, which uses adjustable reverberation, which is unrealistic in terms of investment). As long as we ask the owners to clarify the main functions So as to determine the sound quality design index according to the main use functions, but the following use function conditions must be met:

High language clarity

When using sound reinforcement, it is necessary to have a certain degree of music fullness to spread music

Meet the specified sound field nonuniformity (no sound reinforcement: ≤± 3dB, with sound reinforcement: < 8dB (level I), < 10dB (Level II and level III)

The auditorium has enough sound pressure level

2.2.3 analysis of architectural scheme and suggestions of sound quality design for architectural modeling and other technical considerations

Architecture and sound quality design are required to be carried out simultaneously, but the objective operation is always the construction scheme first, and other disciplines gradually intervene, so is sound quality design. So:

First of all, sound quality design engineers should analyze the congenital conditions of acoustic environment according to the spatial shape of the auditorium designed by the architect, and try to avoid the shape of acoustic defects, such as the dome, arc roof, walls that are easy to cause acoustic focus, multiple echoes, and walls that are easy to cause echo or vibration echo, as well as large-area glass curtain walls, etc., so as to create a good congenital condition for the in-depth design of architectural sound For this reason, it puts forward reasonable suggestions to the architect for sound quality design.

Propose to the structural engineer the space and load requirements reserved for the layout of acoustic decoration and sound reinforcement system.

2.2.4 estimated total sound absorption a

Calculation formula of reverberation time:

T60= kV

-Sln(1- ā)+4mV

This formula is used to calculate the reverberation time of the hall after we know the hall volume, sound absorption and other factors. We can't wait for the acoustic material to be determined before we calculate the reverberation time. Instead, we can determine the amount of absorption needed according to the reverberation time index that has been determined based on the known hall volume. This requires us to use the formula in reverse. Generally, for the sake of simplicity and intuition, we should use the formula at the sound quality design scheme level The following formula is used for the estimate of the segment:

T60= kV

S

KV

ā= ST60 A=ΣSā

The total sound absorption is calculated, and the next step is how to choose the right materials and arrange them in the right position.

2.2.5 reverberation time control and selection of sound-absorbing materials

It can be seen from T60 = kV / s ਑ formula that there are two main factors to control the reverberation time. The reverberation time is directly proportional to the hall volume and inversely proportional to the total absorption volume a, which requires the sound quality design engineer to coordinate the overall operation of the building.

Choose the best volume

The requirements for the use of gymnasiums have determined the minimum clear height, so there is a basic volume. In the past, we used to set ceiling to adjust the volume. Now most gymnasiums use space grid structure, and are fully exposed steel grid structure. That is to say, under the same conditions, to achieve the original reverberation time, we must increase the use of sound-absorbing materials In the sound quality design, measures to reduce the space volume shall be considered as much as possible according to the hall shape, such as increasing the local ceiling, suspending the sound absorption body of the space, separating the unnecessary space, etc.

Selection of sound-absorbing materials and structures

There are many kinds of sound-absorbing materials and various structural forms:

Fibrous

Granular porous sound-absorbing material

Foamy

Single resonator

Resonance sound absorption structure of perforated plate of sound-absorbing material

Resonance absorption structure

Resonance absorption structure of thin plate

Special absorption structure plant fiber spray coating

Space absorbers, wedges, etc

a) Select full frequency domain strong absorption structure

Because the space volume of the gymnasium is large, and there are relatively few places where the sound-absorbing materials can be arranged, the use of sound-absorbing materials can be effectively controlled by selecting materials with wide sound-absorbing frequency band and high coefficient, and the corresponding materials can be selected for the parts with insufficient sound-absorbing capacity of individual frequency, for example, if the low-frequency reverberation is long, the resonance sound-absorbing structure will be increased;

b) Combined with the building structure, select complementary materials and structures, which will not affect the visual effect of the decoration, but also play an absorption role. For example, for the grid structure, select the inner panel of the roof above the grid for sound absorption treatment. For the special enclosure structure, such as large area glass curtain wall, select the double fold sound absorption curtain or transparent film sound absorption material and structure treatment.

c) Choose the most effective sound-absorbing parts to arrange sound-absorbing materials

The top of the gymnasium is the place where the sound-absorbing materials are mainly arranged, especially the place where multiple echoes are most likely to be generated above the competition ground, so it is also the place where the sound-absorbing efficiency is high.

Strong sound absorption treatment is applied to the walls around the venue, the podium and the referee seat, which can effectively reduce the reflected sound entering the microphone and improve the sound transmission gain of the sound reinforcement system.

3. Sound quality design of special Gymnasium

Special gymnasium, also known as single gymnasium, only accounts for a few in the construction of gymnasium, because most items, such as basketball, volleyball, table tennis, badminton, fencing, boxing and gymnastics, can be carried out in the comprehensive gymnasium. At present, the single gymnasium mainly consists of swimming gymnasium, Tennis Gymnasium, track and field gymnasium, shooting gymnasium, etc., which are not generally used as multi-functional, with single technology requirements, Therefore, the requirement of sound quality is not high, but it has its own characteristics in acoustic processing.

3.1 sound quality design of swimming pool:

Each swimming pool has a large volume, especially the one with a jumping pool

25m above;

The floor is made of ceramic tiles. The ceramic tiles and water surface reflect the sound waves strongly;

The relative humidity in the museum is high. In order to control the reverberation time and suppress the sound quality defects, the selected materials and sound-absorbing structures must not only have strong sound-absorbing performance, but also be moisture-proof or even waterproof.

3.1.1 sound quality index of swimming pool:

Reverberation time: the reverberation time at 500Hz ~ 1000Hz is as follows:

Reverberation time (s) of swimming pool grade under different volume (m 3 / seat)

Super and class a < 2.0 < 2.5

Class B and C < 2.5 < 3.0

Frequency characteristics (ratio of reverberation time to 500hz-1000hz)

Frequency (Hz) 125 250 2000 4000

Ratio 1.0 ~ 1.21.0 ~ 1.10.9 ~ 1.00.8 ~ 0.9

Sound field nonuniformity:

< 3dB at 500Hz ~ 1000Hz

3.1.2 key points of sound quality design and selection of materials for swimming pool:

There are three characteristics and difficulties in the sound quality design of natatorium, which are also problems that must be solved in the engineering design. The sound quality requirements of natatorium are not high. Generally speaking, it is required to listen to a short speech and report the results of the competition and the personnel list of the athletes. It is also the language intelligibility that we usually speak. It is not allowed to have acoustic defects such as echo and vibration echo, but several design points and materials are included The principle of material selection must be grasped.

The water surface is almost 100% acoustic reflection surface, also known as specular reflection. Therefore, the top surface of the swimming pool corresponding to the water surface must be treated with strong sound absorption.

No matter whether there is auditorium or not on the side wall, there must be one side of the two corresponding walls for sound absorption.

The surface of the top material must be free from condensation.

All sound-absorbing materials must have the physical properties of moisture-proof, waterproof and mildew proof.

The light trough arranged in the top material must be parallel to the swimlane.

The lighting arrangement above the platform must be balanced.

3.2 design features and differences of sound quality of other special pavilions

3.2.1 skating rink

Sound quality design requirements are similar to those of swimming pools.

The indoor and outdoor temperature difference is large, the roof dewing and dripping affect the use function, and affect the sound absorption performance of the material.

The requirements for the sound quality of the skating rink used for ice hockey and speed skating are not high, which is mainly to control the noise in the rink. However, when it is used for figure skating performance, the requirements for the sound quality are high. If the reverberation time is too long, it will affect the strength and rhythm of the music and the definition of the commentary. If the reverberation time is too short, it will affect the fullness of the music. The multi-functional gymnasium should be used for the design of the skating rink with such functions as the main one, when it is full of reverberation About 1.5s is recommended.

3.2.2 track and field hall

Track and field gymnasiums are usually larger than swimming gymnasiums, but their characteristics are that large areas of ground are all land or lawn, so it is not difficult to control the reverberation time. The necessary language clarity in the gymnasium can be ensured by arranging sound-absorbing materials at the top or at the parts easy to cause echo.

3.2.3 Tennis Hall

The tennis hall is characterized by large volume, small audience and large volume of each seat. The sound quality design only requires language intelligibility, and the reverberation time is less than 3.0s. However, special attention should be paid to prevent the parallel walls from causing echo and vibration echo, because this defect will mislead the players' judgment on the direction of the landing sound of tennis balls and cause errors. Therefore, the echo and vibration echo of the wall must be solved by means of absorption and sound diffusion.

3.2.4 indoor range

The sound quality design of shooting range is mainly to control the noise, which is not only for the needs of audience, athletes and referees, but also to protect the health and hearing organs of athletes.

The acoustic design of shooting range mainly includes the following aspects:

Reduce reverb

Try to reduce the sound reflection caused by shooting sound in the room, and the reverberation time is recommended to be ≤ 1.0s.

Echo cancellation

Prevent echoes and tremors caused by gunshots.

When shooting, the sound pressure level of the athlete's ear should not be greater than 105dB (a)

During the competition, the sound pressure level of shooting from adjacent targets shall be lower than 105 dB (a) (average value of 125hz-4000hz)

Key measures in design:

In order to reduce the muzzle noise, echo and the vibration echo of the interior side wall, in addition to the strong absorption treatment near the muzzle, the strong absorption treatment should also be carried out on the rear wall of the target. However, the material selected on the rear wall of the target position in the indoor shooting range should not be selected as the metal perforation material in order to prevent the slide or bounce.

The above focuses on the sound quality design of comprehensive gymnasiums and professional gymnasiums, which is introduced from the basic theory and measures. However, in the actual engineering design, there are constantly new problems, which need to be solved by the acoustic workers one by one. The following is an introduction to the new topic that the era characteristics of modern sports architecture put forward for the sound quality design.

4. The era characteristics of modern sports architecture put forward new topics for sound quality design:

The sound quality design mainly obeys and adapts to the shape design and decoration pattern of the architect. The Acoustic Engineer has changed from the consultant type in the past to the challenge type.

The space of sports building is more and more large, and there are less and less places where sound-absorbing materials can be arranged. Therefore, strong sound-absorbing materials and structures are preferred.

The stadium has reverberation time and no reverberation time. In the past, there was a roof in some parts. Now there is a canopy over the auditorium. In the past, the back of the auditorium was empty. Now it is full of several conference rooms, reception rooms and VIP rooms, and it has become a completely closed enclosure structure.

5. Design experience:

The basic principles of sound quality design are very simple and clear. What is required and what is opposed to are very clear. However, when these principles are applied to specific engineering practice, the answer is diverse. Specific sound quality design is a colorful and highly creative work, so I can't be considered to be able to engage in sound quality design if I know the basic concepts, because architectural acoustics is a science, With the deepening and development of the research work, the basic principles will continue to develop in details and specific understanding, and new problems will continue to emerge. At present, multi-functional gymnasiums are more common. Owners and leaders often require the construction of multi-functional halls, which can be used for anything, can act, can make reports, can play movies, but in fact, it can not be done, It can only be a compromise result. It can act and report. Of course, it's very good, but the acting can't achieve the best effect, and the report can't achieve the best effect. What can we do? The acoustic engineer designs according to the main functions, and then adjusts and compensates appropriately with the help of the sound reinforcement system.

In recent years, as the sports buildings are at the climax of construction, I have the opportunity to participate in the acoustic design of stadiums and gymnasiums. According to the venue of the 10th National Games - Nanjing Olympic Sports Center, Jiangsu Provincial Games venue - Nantong Sports Exhibition Center, there are also the acoustic design practice of sports buildings in Colleges and universities and small and medium-sized enterprises. I have accumulated some experience and many lessons. What I deeply feel is acoustics The success or failure of the project depends not only on the ability of the acoustical workers, but also on the good cooperation of the architects, which must be based on the architects' more understanding of acoustics and the common language.