2 Zone Compact highly integrated voice alarm and public address system is your good choice.The general public address system can be divided into six parts: audio source output equipment, audio source pre-input equipment, power amplifier equipment, transmission line, speaker system and various management control equipment.
(1) Audio output equipment
The audio output equipment of the public broadcasting system generally includes digital tuners, deck recorders, MP3 program timing players, CD players, DVDs, alarm signal generators, microphones and other equipment that can provide audio signal reading and storage.
(2) Pre-input equipment for audio source
Most of the audio signals input by the audio source output device are millivolt-level weak signals, which need to be amplified to a rated level before being input to the power amplifier, usually about 1V. The audio source pre-input device can also be called a pre-amplifier. On the one hand, it plays the role of selecting the required audio source signal and amplifying it to the rated level; on the other hand, it can adjust the frequency characteristics of the sound to realize the modification of the sound quality of the output signal. And control. Common audio source pre-input devices include pre-mixing amplifier (mixer), pre-amplifier or matrix mixing amplifier.
(3) Power amplification equipment
Power amplification equipment is the largest number in the entire public broadcasting cabinet and the most important thrust in the sound transmission system. They are responsible for amplifying the audio signal integrated and output by the audio front input equipment, and then pushing the speaker to emit sound through the transmission line. The common power amplifier equipment in the system includes fixed-voltage power amplifiers such as integrated power amplifiers and pure post-stage power amplifiers.
(4) Transmission line
In places such as auditoriums, lecture halls or theaters, because the distance between the power amplifier and the speakers (group) is not far, the direct feeding method of low resistance and high current is generally adopted. The transmission line uses a dedicated audio cable (speaker cable), and the copper wire of the audio cable is required. Pure, the core wire should be thick; and for the public broadcasting system, due to the wide service area and long signal transmission distance, in order to reduce the loss of the signal in the transmission line, the high-voltage transmission method is often used. Because the transmission current is small, the transmission line is required not tall.
(5) Speaker system
The speaker system must match the entire broadcasting system, and the location of the speaker system must be realistic. Auditoriums, theaters, song and dance halls require high timbre and sound quality, and speakers generally use high-power speakers. In the public address system, due to the low level of timbre requirements, business public broadcasting usually uses speakers (outdoor) of about 20W. Use 3W-6W ceiling speakers inside.
(6) Management and control equipment
The management and control equipment can automatically control the startup, shutdown and sound output of the system. At present, the operation of most public address systems can achieve a certain degree of intelligence. From the signal flow point of view, management control equipment can be divided into audio source management control equipment (computer + control software, also called intelligent control host, capable of storing and playing audio files, having functions such as program presets, partition control, etc.), timing power manager (Turn on and off the equipment in turn at regular intervals to realize unattended), output management control equipment (broadcast partition matrix, which can play different programs in different broadcast partitions at the same time, and distribute program signals to different partitions for broadcasting through the matrix partitioner. Different program sources can be broadcast at the same time or at different times, and the programmable program timer can run automatically according to the pre-programmed program, and it can also be manually adjusted at any time). 2 Zone Compact highly integrated voice alarm and public address system is your good choice.