The public address system has three different implementations depending on its transmission medium, constant pressure broadcast, FM radio and digital network broadcast.
    1. The constant pressure broadcasting system is the most widely used in various schools, with the characteristics of simple system, low cost and quick implementation.
    2. The main feature of FM radio system is that it can broadcast multiple programs at the same time. The receiving end can choose to listen to different programs according to needs. It is mainly used for school listening test and listening training. In multi-language teaching, FM radio is also divided into wired and Wireless two ways; wireless mode is mostly used in areas with large broadcasting range, schools that do not require high sound quality, and the transmission power and frequency must be within the allowable range of the country;
    3. Digital network broadcasting is based on the campus broadcasting system and is a trend in the development of broadcasting systems.
    In the past two years, there have been successful cases in some schools. One of the outstanding features of network broadcasting is that it can be realized without the need of rewiring, only with the help of the campus network, and its control function can not only control across network segments, but also cross-route control. It is also very easy to implement. This is difficult for other broadcasting systems. Now many universities and well-known primary and secondary schools have many different samples. Through digital network broadcasting, it is possible to achieve a total sample broadcast of all the samples. This will be Broadcasts without geographical restrictions, just like radio stations, each school’s campus radio can achieve daily broadcasts to the whole school, but digital network broadcasting is still costly, and there are still some practical problems to be solved, but Which kind of broadcasting system has its corresponding knowledgeable products, Beijing Jinmai Video Technology Development Co., Ltd. has developed a series of products of intelligent broadcasting system, mainly including "campus addressable FM broadcasting system", "campus addressable Constant Pressure Broadcasting System", "Intelligent Constant Voltage Partition Broadcasting System" "Multi-    channel Digital Broadcasting Broadcast Control System" Internet Broadcasting Systems, "" Call the apartment intercom system "and so on, the product series is mainly to meet the different regions, not schools sign of trouble, no trouble of investment, not sign of trouble is broadcast needs, make the best solution.
    The main features of the campus intelligent broadcast system:
    1, automatic play, timed play, loop play, remote play, stereo play
    2, fixed point play, group play, partition play, cross-regional play
    3, multi-channel programs play at the same time, pre-order playlist
    4, the playback capacity is large, play a variety of file formats
    5, partition control, addressing control, power control
    6, call intercom, inter-frequency on demand