Indoor acoustic treatment and equipment installation of dome theater

1. Indoor acoustic treatment The top of the dome theater is a hemispherical structure. In terms of acoustics, there are problems with sound focus and sound absorption and noise reduction in the entire space. According to the architectural structure of the theater, in order to meet the indoor sound absorption and noise reduction effect, more than 50 suspended sound absorbers are installed on the top of the sphere to break the focus formed by the spherical sound reflection and solve the sound focus problem. The walls under the auditorium and the sphere are arranged in different combinations by using perforated panels and cavity sound absorbers, and the floor is covered with carpets, which absorbs the high, medium and low frequency sounds in the theater and ensures the clarity of sound playback in the theater. Spend. 1. Sound focus processing. Because the top of the theater has a spherical structure, the sound focus will be formed in the auditorium. For this reason, we hang two sound absorbers with different specifications on the top (see Figure 1 and Figure 2), and the sound absorbers are vertical and horizontal. Arranged at intervals to absorb and destroy the focus of sound. Figure 1 The layout of the sound-absorbing body in the headspace Figure 2 The cross-section of the dome theater 2. Sound absorption and noise reduction treatment Because the spherical screen is a microporous aluminum plate. Therefore, the optical requirement of the theater for the interior is that all background materials must be matte black to prevent light reflection from affecting the quality of movie playback. Spray the matt black paint on the inner wall structure of the sphere, and then lay the matt black film on the surface to absorb the indoor mid-frequency sound and meet the optical requirements of the theater. In the construction of the background wall, a combination structure of perforated panels and cavity sound-absorbing bodies is used for wall decoration. After the sound-absorbing material is put into the sound-absorbing structure of the perforated plate, the impedance composite sound-absorbing structure is formed. There are three placement schemes for sound-absorbing materials in the cavity behind the board: ① The sound-absorbing material is close to the inner wall of the perforated board and a certain cavity is left between the rigid wall; ② There is a space between the sound-absorbing material and the inner wall of the perforated board and between the rigid wall. Cavity; ③ The sound-absorbing material is close to the rigid wall and a certain cavity is left between the inner wall of the perforated plate. After the sound-absorbing material is added to the sound-absorbing structure of the perforated plate, the resistance of the air near the hole neck is increased, so that the sound absorption coefficient can be improved and the sound absorption frequency band can be widened. Obviously, the closer the sound-absorbing material is to the perforated plate, the more obvious the sound-absorbing effect. Therefore, when the sound-absorbing treatment is carried out in the project implementation, the first solution has the best sound-absorbing effect. The first construction technique is adopted in the construction of the background wall. A black cavity sound absorber is installed in the steel frame, and a perforated cement fiber board is externally sealed (see Figure 3) to absorb mid-, high-frequency and low-frequency sound. The perforated cement fiber board is sprayed with black paint, and the board is sealed after the paint is dry to prevent the holes from being blocked by spraying after the board is sealed. Figure 3 Cavity sound-absorbing body structure The inner wall of the auditorium is made of steel frame-sealed perforated cement fiber board, and a dark blue sound-absorbing body is pasted on the outside to absorb high-frequency and low-frequency sound and meet the aesthetic requirements of interior decoration. The floor is carpeted. Sound-absorbing structure of auditorium II. Equipment installation The whole system of playback equipment and spherical screen of the dome theater are all imported from the United States. First, since the frame of the spherical screen is an aluminum alloy frame and the screen is a microporous aluminum plate, the connection of the spherical screen frame and the civil steel structure ring beam requires welding 50 steel bolts on the steel ring beam to connect to the screen frame. In this process, the laser theodolite can be used to measure and pay off. In the dome theater, 50 connection points are determined on the upper part of the structural steel ring beam (diameter 19 meters) inclined 24°, and each connection point is separated by 7.2°, and Weld 50 steel bolts on the connection point to fix the spherical screen. Secondly, in the installation process of the screen and equipment, the indoor temperature is required to be controlled at 23-25°C, the humidity should not exceed 70%, and no dust is allowed in the room to avoid deformation of the screen and keel due to the influence of temperature and humidity. In order to meet the installation conditions of indoor equipment, after the completion of the base layer and coating project and before the installation of the dome equipment, the entire construction site must be cleaned and vacuumed, and the ground base layer must be painted with sealing paint. Then set up a super-work platform in the auditorium (see Figure 5). The scaffolding used must be derusted, dust-removed and painted. The platform planks and wooden squares are laid with new materials to ensure that no dust will be generated during use. Install 6 5-hp split air conditioners and 3 high-power dehumidifiers evenly in the theater, 1 air conditioner and 1 dehumidifier in the equipment room, and 8 dry and wet thermometers at different positions and heights indoors to monitor indoor environment. Plan view of the operating platform area. Sectional view of the operating platform. The installation of the keel is to install 3 arc-shaped vertical keels at 120° of the circular steel ring beam, and fix the round members on the spherical top. The circular members are the key to the connection and positioning of the entire dome keel. . Then install other arc-shaped vertical keels and transverse support keels in sequence. The screws must not be screwed down when the keels are installed. After all the keels are completed, they can be tightened after measurement and adjustment are completed. After the entire dome frame is installed, the screen is installed. The screen is a spherical microporous aluminum plate, and there are requirements for the direction and sequence of installation. During the installation process, the construction personnel must wipe their hands clean with disposable wet paper towels and keep their clothes clean to avoid contaminating the screen. After the screen is installed, the final surface layer of the screen is painted. The spray angle is 20°～30°, and spray in one direction to ensure uniform spraying and avoid clogging the micro holes on the screen. After the screen paint is dry, proceed with the disassembly of the super work platform. Fully vacuum before disassembly, no strong vibration or dust