Engineering guidelines for sound reinforcement system in Theatre

1. The planning process of sound reinforcement system in Theatre

The sound reinforcement system planning of theatre and auditorium includes two parts: architectural sound planning and electroacoustic sound planning, and is the unity of the two. This section focuses on electro acoustic planning. The sound reinforcement system planning of theatres and auditoriums can be divided into five stages with the deepening of architectural planning. The sound reinforcement system planning can also be summarized as follows, as shown in Table 11-2.

Composition of theater sound reinforcement system

The preliminary planning process and contents of the sound reinforcement system for theaters and auditorium are shown in Figure 11-3.

Preliminary planning process and content of sound reinforcement system for theatre, auditorium, etc.

Two. The composition of theater sound reinforcement system.

1. fundamental components

The audio signal flow of the sound reinforcement system in theaters such as general theaters is shown in Figure 11-4 (a). The basic composition of the sound reinforcement system is shown in Figure 11-4 (b). If a digital mixer is selected, the signal processor can be contained inside the digital mixer.

Composition of theater sound reinforcement system

2. voice input device

The composition of the sound input equipment is shown in Fig. 11-5 (the equipment in the solid line is located in the stage and auditorium, and the equipment in the dotted line is located in the sound control room).

The microphone is divided into wired microphone and wireless microphone. It has been stated in the third chapter. When the receiver antenna of the wireless microphone can not receive the signal well, a special receiving antenna should be set up near the stage to transmit the signal to the receiver in the sound control room. The receiving antenna is usually arranged near the stage. In addition, we should also pay attention to the settings of the following devices.

(L) auditorium microphone for auditorium

Set in the auditorium in the best sound conditions of the azimuth, the general equipment in front of the platform or the auditorium wall, should be set in the auditorium on both sides of the stage panoramic camera. According to the sound condition of the equipment azimuth, two microphones with the same characteristics should be used to pick up the sound with different directivity.

(2) three point lifting microphone device

Set up above the orchestral pool outside the station, and control the position of the hoisting point through three lifting points. Generally there are l to 3 points of application, two points per point. In addition to being able to control inside the voice control room, it can also operate on the stage.

(3) microphone terminal box

(1) It is necessary to set up a microphone junction box in as many directions as possible in the entire stage area. There should be isolation around the microphone socket box.

Composition of theater sound reinforcement system

(2) It is necessary to separate the microphone junction box and the speaker system junction box and not to mix them with other sockets.

(3) The stage board microphone circuit and the speaker circuit dedicated junction box, in addition to the front center of the stage, the stage, the end, the announcement, the host often used in the position, on both sides of the stage, side curtain and two curtain, three curtain adjacent should also be set. Set up the orchestra junction box according to the need. Figure 11-6 shows an example of the position of the stage plate junction box and the inductive junction box.

4. No junction box should be set up in stage playing area and artiste passageway.

(5) the opening of the junction box cover must be directed towards the stage so as to facilitate the outlet.

(4) stage inductive terminal box.

It is necessary to set up inductive junction box on both sides of the platform. The inductive junction box on the back side of the stage is determined according to the theater planning and operation status. When there is a music pool, it is generally appropriate to set similar inductive junction box on the back wall of the music pool.

The number of interfaces in each inductive junction box is determined by the sound reinforcement system. Generally, there are not less than 16 microphone circuits and 4 loudspeaker circuits, and two or more 27-core or 37-core multi-functional sockets are installed together. If there is an activity tuning station in the auditorium, the necessary number of loops should also be added.

(5) auditorium inductive wiring panel

It is necessary for large and medium-sized theatres to set up inductive wiring boxes under the seats of on-site tuning positions and connect them with inductive wiring boxes or voice-controlled indoor jumper boxes at the entrance of the stage to form a signal transmission circuit. It is necessary to set up a special power supply for sound reinforcement system in the vicinity of the inductive junction plate, usually 220V single phase, not less than 5kVA.

Composition of theater sound reinforcement system

3. The minimum net area of the acoustical control room and its operating equipment should be larger than 15m2, and the minimum dimensions of height and width should be 2.5m.

The nest should be large enough to enable the operator to see the playing area of the rostrum and 2/3. The window should be open so that the sound in the hall can be heard directly. In order to facilitate the laying of wires, the control room usually chooses overhead anti-static floor. Control room roof and wall should be made of sound absorption structure to improve monitoring conditions. The control room should have excellent ventilation and independent air conditioning. Figure 1l-7 shows an example of a voice control room.

Composition of theater sound reinforcement system

The sound control indoor audio equipment is the device of the dotted line box in figures 11-5 and 11-6. It includes a mixing station, peripheral equipment, audio recording and playback equipment, wireless receiver and listening speakers. According to the planning and application requirements of theaters, there are several kinds of mixer for theaters.

(1) the main sound reinforcement mixer: the operation and operation center of the theater's sound reinforcement system. It is necessary to set up at least one special mixer for fixed equipment in the voice control room. According to theatre planning and application intention, 16-48 input channels, 4-8 marshalling channels, 4-8 auxiliary channels and 4-8 matrix output channels should be used.

(2) Auxiliary mixing station: In order to compensate for the lack of channels in the main amplifying mixing station, it is sometimes temporarily set up near the stage for simple tuning operation. In addition, it is also used for monitoring incoming calls, recording and so on. Mixers with 16-24 input channels, 4 auxiliary channels and 4-8 marshalling output channels should be equipped. Sometimes it's also dedicated to stage mixer.

(3) Movable mixing platform: When the main amplifying mixing platform is not used, a temporary mixing platform is set up near the stage or in the auditorium. The new theatre is usually set up and is generally determined on the basis of investment.

The sound source devices for recording and playing in the voice control room are as follows.

(1) Hard disk recorder: the most important sound source equipment in sound reinforcement system, which is generally stored on the hard disk of the accounting machine, can be edited and processed on the accounting machine, and can output signals for various patterns. The selection of music is convenient and fast, and can be broadcasted instantly. It is necessary to equip two compatible devices, one main and one standby.

(2) CD broadcasting machine: the most important music reproduction method in the sound reinforcement system. We should choose professional equipment with high reliability and instant broadcast function. It should be equipped with two sets, one main and one standby, and it can also be equipped with CD-R recorder.

(3) Cassette tape recorder: One of the most important sound source equipment in sound reinforcement system, it is necessary to use strong and reliable professional equipment, generally separate recording and replay, and equip two identical equipment to back up each other.

(4) MD broadcasting machine: we should select devices with excellent sound quality and instant broadcast.

There are the following devices for placing in the voice control room.

(1) Input/output jumper disc: The sound signals of inductive junction box and various microphone equipment, as well as actors, recorders, etc. from the stage are connected to the mixer through the input jumper disc and the input channel is exchanged. Together, the output of the mixer is transmitted to the input of the amplifier and communicated through the path.

2. Connection terminals: audio signals and control signals need to be set apart.

Power amplifier operation condition monitoring equipment: in the sound control room can recognize the power amplifier output and loudspeaker system operation condition monitoring equipment.

(4) Monitor loudspeakers: a system of loudspeakers set in front of a mixer in a sound control room and used by an acoustician to acknowledge the role of sound in the final field. The final sound in the auditorium that can be monitored by the microphone collection can be arbitrarily switched from the sound of the microphone being used by the artist.

_Call equipment: Interphone and call equipment set up in the sound control room, stage operators and cosmetic rooms, stage, auditorium and other places to communicate with the sound amplification broadcast equipment. It can also be recorded in real-time. The primary content is to record the speech between the performers in the memory so as to check the errors in the work.

4. equipment in the power amplifier room

Because the theater area is large, the speaker system is located on the side of the stage, far away from the sound control room, so the theater is often located near the stage amplifier room. The power amplifier room is equipped with a loudspeaker processor (or speaker controller) and an output jumper disk in addition to a large number of power amplifiers. As a part of the loudspeaker system, the loudspeaker processor has the functions of equalization, amplitude limiting, frequency dividing, delay and so on. It is used to adjust the loudspeaker system to the best operating condition. The output jumper is the wiring board between the power amplifier output and the speaker system.

5. theater loudspeaker system equipment

Theatre loudspeaker system is generally set in the following directions, specific in the project selection in the sound reinforcement system planning to determine.

(1) speakers above the platform

The loudspeaker system is the most important sound reinforcement system. In order to cover up all the auditorium effectively, it is usually set above the stage opening and in the front part of the ceiling of the auditorium. Generally, according to the width of the platform, height and the width of the audience seat is different, often choose three methods: the middle group, left, right each group, left, middle, right each group.

(2) speakers on both sides of the platform

Set in the auditorium on both sides of the table. It is mainly used in the front area to make up the sound. Together, it can make the sound image of the loudspeaker system above the platform move down, that is, pull the sound image. Should be used together with the main amplifier above the table mouth, suitable for the use of similar products, to prevent the occurrence of different sound quality.

(3) platform lip sound box.

It is set on the front lip of the stage or on the railing of the orchestra pool. It is mainly used in the front area to make up the sound and pull the sound. Because the orientation is small and difficult to use, the loudspeaker system with a small scale is generally chosen, with a distance of 2 to 3m. Sometimes it can not be set according to the specific conditions of the project.

(4) stage stage speakers

Temporarily set up on both sides of the stage U, according to the needs of the activities set up the use of speakers. When using it, the lead of the junction box is induced from the table mouth, and the necessary speaker interface is set on the stage board or the inductive junction box.

(5) side wall and ceiling sound box.

The sound box is installed in the inner wall, back wall and ceiling of the auditorium. It is mainly used for the thunder, gale, and the movement of vehicles and boats. The professional opera theater uses large equipment, and the general multi-functional theater mostly uses small speaker system. In addition, these loudspeaker systems are used as surround loudspeaker systems when showing movies.

(6) the sound box under the gazebo.

A loudspeaker set under the gazebo. In order to compensate for the lack of sound under the viewing platform in the auditorium, the roof-absorbing loudspeaker equipment is often used, and the power is small.

(7) stage fixed return speakers.

Generally, a fixed return sound box is set in the side wall or the false stage opening of the stage entrance and the stage entrance, which is broadcast in the direction of the stage.

(8) return to the speakers.

When performing activities, such as concerts, the activities set on the stage return speakers, or in the middle of the sidebar with the speaker bracket set up in the activity return speakers, etc., on the stage board or inductive junction box set up necessary speaker interface.

6. sound reinforcement system signal

For analog transmission, the preferred value of electrical interconnection should be satisfied with the rules of GB/T 14197-1993. The balanced transmission method should be adopted between system equipment. Digital transmission and interface should agree.