The ultimate purpose of sound reinforcement system design is to ensure that the sound source and the end speaker of the sound system are in the same sound field area, so that the audience can feel the real existence of the sound source and achieve the sound reinforcement requirements of high fidelity playback.
1、 Design conditions of sound reinforcement system
In order to achieve good sound quality, the design of sound reinforcement system must meet some necessary conditions, which are the basic requirements for the acoustic index design of the whole sound system.
1 low background noise
The auditorium and room used for sound reinforcement must have low background noise. The noise may not only come from the outdoor, but also from the indoor, such as the noise generated by the movement of air conditioning, ventilation equipment and optical equipment, etc. measures should be taken to reduce the noise in the listening environment as much as possible.
If the noise is too high, the clarity and intelligibility of the sound reinforcement system will be reduced, and it is difficult to make the sound system achieve the desired sound quality. When the output power of the equipment is increased to improve the output sound pressure level, the sound feedback may be caused and the system can not work stably.
The problem of indoor noise control must be fully considered in construction and decoration, and necessary sound insulation measures should be taken. Generally, the background noise of cinema is 25-30db, that of lecture hall is 30-35db, and that of gymnasium is 47-56db.