First, the design of the sound reinforcement system

The sound reinforcement system design usually starts from the sound field design and gradually advances backwards to the power amplifier, sound processing, mixing console and sound source. Because the sound field design is the basis for meeting the functions and sound effects of the system. Therefore, the design process of the public broadcasting system, which is backwards, is very necessary.

(1) Sound supply scheme for indoor sound reinforcement system

Select the sound solution according to the function, room size and service area size.

1. Centralized sound supply (point sound source for sound)

Advantages: It can effectively reduce the interference between sound sources, with clear sound quality, consistent viewing direction, natural listening sound and uniform sound field.

Disadvantages: The loss of sound energy is large, it is not suitable for rooms with low space and long and narrow rooms. The height of the speaker suspension of the centralized sound system should not be lower than 8~10m, otherwise the sound field is not easy to be uniform.

2. Decentralized sound supply

Applicable to narrow rooms, lower height rooms, rooms with longer reverberation time or tunnel sound reinforcement systems.

Advantages: Uniform sound field and low loss of sound energy.

Disadvantages: Inconsistent audio-visual, high interference between sound sources, especially in the overlapping areas of two sound sources covered with poor sound quality....

Second, public address system sound reinforcement system classification

(1) Classified by job

1. Sound reinforcement system: The microphone and the speaker are in the same sound field, there is a condition that the acoustic feedback is self-excited, and the sound gain is limited.

2. Sound release system: Only the sound source such as deck, CD player, etc., there is no acoustic feedback condition, which is a special case of sound reinforcement system.

(2) Classified by purpose

1. Outdoor sound reinforcement system: stadium, art square, music fountain, large-scale mobile performances, etc.

Characteristics: wide space, large service area, large background noise, and affected by the reflection of surrounding buildings. Directly speaking, there is no reverberation sound. When the reflection sound delay exceeds 50ms (17m), there will be heavy or echo, which will affect the sound clarity and sound image localization. Acoustic effects (especially musical fountains) are also affected by climatic conditions, wind direction and environmental disturbances.

2. Indoor sound reinforcement system: various theaters, gymnasiums and dance halls.

Characteristics: The professionalism is very strong, and the system configuration is different depending on the function. The sound construction condition has a great influence on the sound effect.

3. Mobile performance system: A system commonly used for large-scale performances and temporary installations.