Performance buildings include various cinemas, theaters, theaters, audio-visual rooms, exhibition rooms, studios, recording studios and other multi-purpose hall buildings.

The acoustic design of performance architecture involves structure, figure design, sound quality design and sound insulation. For the performance architecture for natural sound performance, the acoustic design mainly focuses on architectural acoustics, such as the concert hall for natural sound performance.

Since the 1980s, a number of newly designed concert halls have become increasingly sophisticated in the requirements of acoustic environment. Even professional concert halls hope to perform music works of different styles and types beautifully. Even with high fidelity, high-grade sound reinforcement systems can not be achieved. But it can be realized through architectural acoustic design. Such examples abound, such as Boston Concert Hall (1900), Sydney Opera House Concert Hall (1973), Birmingham Symphony Hall (1991), etc. Many people mistakenly believe that for some performance buildings that perform with sound reinforcement (for example, most modern theaters use sound reinforcement), as long as there is a high fidelity sound reinforcement system, the performance requirements of theaters can be met. In fact, the effect of the sound reinforcement system cannot be achieved without the sound reinforcement system. No matter how good the sound reinforcement system is, it cannot play its role without good architectural sound design as the premise. Because the sound reinforcement system can not eliminate a variety of sound quality defects, such as sound staining, sound focusing, multiple echoes, and flutter echoes.

For performance architecture, the concept of acoustic design should be introduced at the early stage of architectural design. It runs through the whole process of architectural design and decorative design from beginning to end. Only in this way can we build high-quality performance buildings.

1. Overview of Acoustic Design of Theatre Buildings

The function of modern theater is to perform drama, drama, opera, singing and dancing, quyi and music. At the same time, it is particularly important to meet the requirements of architectural acoustics design for the multifunctional use of the theater. The acoustic design of theater buildings involves structure, figure design, sound quality design and sound insulation. The performance architecture and architectural acoustic design for natural sound performance are mainly concerned. Acoustic design should be considered at the beginning of architectural scheme design. The acoustic designer shall participate in the whole process of civil engineering and decoration design. In each stage of engineering design, it shall be carried out synchronously with relevant design disciplines and closely cooperate with them.

The volume calculation is bounded by the curtain line. The stage is equipped with a music hood, which shall be included in the volume calculation. The extended stage and island stage are not subject to this restriction.
According to the Code for Acoustic Design of Theatre Buildings (JGJ 57-2000), the theater can be divided into four grades: Special A, B and C.

The volume of each auditorium should meet the following requirements:

2. Relevant standards and regulations for acoustical design of theater buildings

（1）《Code for acoustical design of theaters, cinemas and multipurpose halls》GB/T 50356-2005；
（2）《Code for acoustical design of theater buildings》JGJ 57-2000；
（3）《Acoustic environment quality standard》（GB 3096-2008）；
（4）《Code for design of hall sound reinforcement system》（GB 50371-2006）；
（5）《Specification for reverberation time measurement in auditorium》GBJ76-84；
（6）《Building sound insulation and absorption structure》（National Building Standard Design Atlas 08J931）；
（7）《Code for indoor environmental pollution control of civil construction engineering》(GB50325-2001)；
（8）《Code for Fire Protection Design of Buildings》GBJ16-1987（2001）；
（9）《Code for fire protection design of interior decoration of buildings》（GB50222-95）

3. Acoustical design of theater architecture

Reverberation time

Specification requirements:《Code for acoustical design of theaters, cinemas and multipurpose halls》GB/T 50356-2005

The range of the appropriate reverberation time T for the audience halls with different volume V in the opera and dance theater when the frequency is 500~1000Hz.

The range of the appropriate reverberation time T for the full capacity of the auditorium with different volume V at the frequency of 500~1000Hz.

The sound quality of the auditorium shall ensure that there is an appropriate relative intensity, early sound field intensity, clarity and fullness in the auditorium. During the performance, there shall be no echo, multiple echo, flutter echo, sound focusing and resonance recognizable sound defects at any position in the auditorium, and there shall be no interference caused by equipment noise in the theater and external environmental noise.

Solution

1、The stage space of the extended stage and the auditorium are combined into the same reverberation space, and the reverberation design is based on the same space.
2、The space in the stage acoustic reflector belongs to a part of the auditorium space, and the reverberation of the auditorium with the stage acoustic reflector shall be designed separately.
3、The stage orchestra shall be acoustically designed.
4、Ceiling
The suspended ceiling near the stage shall be made of double-layer 12 thick Eter board, or other equivalent acoustic reflective materials. The installation area is m2, and the shape of the suspended ceiling is progressive wavy. See CAD drawings for specific specifications and shapes of suspended ceiling. The rest of the suspended ceilings are made of perforated sound absorbing materials+glass wool.
5、Metope
MLS diffusers are installed on both sides of the wall near the stage entrance. In order to avoid acoustic defects such as echo, strip perforated sound absorption structures are arranged on the back wall. Due to the need to control the reverberation time of the entire auditorium, a certain amount of acoustic materials are required, and the rear wall area is insufficient, so a perforated sound absorption structure is installed at the rear of the side wall.

《Code for acoustical design of theater buildings》 JGJ 57-2000

6、 Stage
The stage floor adopts double wooden floor. The stage and the auditorium are connected through the stage opening to form a coupling space. In order to avoid the adverse impact of the coupling space on the auditorium and meet the hearing requirements of actors, the reverberation time of the stage is similar to that of the auditorium. Therefore, fabric acoustic panels are installed on the walls facing the audience, and wooden slotted acoustic panels are installed on the walls on both sides of the stage.
7、Ground
The floor is made of reflective wood.
8、Chair
In order to reduce the influence of the audience on the indoor sound quality, the sound absorption of the seats shall meet the following requirements:

The surface layer of the seat is woven fabric, which has good sound transmission performance. The upper and both sides of the backrest are non perforated reflective surface materials, and the lower surface layer of the seat is perforated materials.
9、Other function rooms
Full frequency sound absorbing materials shall be installed in the otopic room, and sound absorbing, reflecting, diffusing and other acoustic materials shall be arranged in the projection room and the box according to the design standards.

4. Sound insulation in acoustical design of theater buildings

Relevant specifications

The Class 1 functional area is applicable to the areas dominated by residential, cultural and educational institutions.
Class 2 functional area is applicable to residential, commercial, industrial mixed area and commercial center area.
Class 3 functional areas are applicable to industrial areas.
Class 4 functional areas are applicable to areas on both sides of trunk roads.

《Code for acoustical design of theaters, cinemas and multipurpose halls》GB/T 50356-2005

Solution

1、The wall and roof of the auditorium shall be treated with sound insulation and vibration reduction.
2、The auditorium should use the lounge (corridor), lobby, etc. as one of the sound insulation measures. The entrance of the auditorium should be equipped with a sound gate and soundproof door.
3、When the observation window in the sound control room is closed, the medium frequency (500~1000Hz) sound insulation is ≥ 25dB.
4、Sound insulation doors shall be used for doors leading to the outside.
5、The intermediate frequency (500~1000Hz) sound insulation of the enclosure of the simultaneous interpretation room shall be ≥ 45dB. The reverberation time of the sound control room and simultaneous interpretation room should be 0.3~0.5s, and the noise generated by the air conditioning system should not exceed NR-25.
6、The noise when the stage curtain is switched on and off shall not exceed NR-40 in the middle of the first row of the auditorium, and the operating noise of the lifting orchestra and other mechanical equipment shall not exceed NR-45 in the middle of the first row of the auditorium.
7、Air conditioning room, fan room, cooling tower, refrigerator room, boiler room and other equipment rooms should be far away from auditorium and stage. When connected to the main building. Good noise reduction and vibration isolation measures shall be taken.
8、For ventilation or air conditioning system, noise elimination and reduction measures shall be taken. The noise transmitted into the auditorium and stage through the air outlet shall be 5dB lower than the indoor allowable noise standard.
9、When the ventilation, air conditioning and refrigeration machine rooms are adjacent to the auditorium and stage, sound insulation measures shall be taken. The sound insulation capacity shall make the noise transmitted to the auditorium and stage 5dB lower than the allowable noise standard. Vibration reduction measures shall be taken for power equipment.

5. Material Requirements for Acoustic Design of Theatre Buildings

（1）The ceiling, wall and floor decoration materials of the auditorium (including the orchestra pit) shall not be lower than Grade A1. When Grade B1 decoration materials are used, corresponding fire-fighting facilities shall be provided.
（2）The keel materials used for ceiling and wall decoration shall be Grade A.