Design broadcast audio system considerations
In the design of the broadcast audio system, the following aspects of the device need to be carefully considered and selected:
(1) System equipment supporting considerations: the main equipment of the system, the partition fire matrix, the volume adjuster, the speaker, and the connecting wires.
(2) Arrangement of speakers: centralized arrangement, decentralized arrangement; setting distance of the speaker: There are two estimation methods, one is to walk from any part to the nearest speaker no more than 15m, the last speaker at the end of the corridor The box is arranged with a distance of no more than 8 m. The second method is to use a 3W speaker with a separation distance of (3-3.5) times the floor height or to ensure that the speaker's electric power density is 0.025-0.05 W/m2.
(3) Power selection of the speaker: The indoor sound pressure level depends on the direct sound radiated by the speaker and the diffused sound generated by the room reflection. The sound pressure level is generally 85 dB in most areas of the sound supply surface. Speakers used in public places such as corridors, halls, restaurants, etc. of the building, if not required, the normal rated power should be no less than 3W; and in places with high environmental noise such as entertainment venues and garages, ventilation rooms, etc. The sound pressure level is higher than the background noise requirement of 15 dB to select the power of the speaker, or the installation distance of each speaker is appropriately reduced to achieve the desired broadcasting effect.
(4) Emergency broadcast partition design: The emergency broadcast partition is composed of a partition fire matrix, an emergency power amplifier, a strong cut power supply, a strong cut volume controller and corresponding circuits. When there is an emergency signal, the partition fire matrix is automatically switched to the tight power amplifier. The strong cut power automatically adjusts the volume controller to the maximum volume, and plays an emergency broadcast or fire alarm signal to make it sound at full power to meet the needs of the broadcast.