Introduction of adjustable sound system with horizontal and vertical directivity

Any sound source has a certain directivity in a certain frequency range. Similarly, any speaker system also has directivity. Directivity is due to the mutual interference of sound waves. Directivity is good and bad for speaker system. Why do we use linear array sound system for sound reinforcement? The main purpose is to make full use of linear array sound system to produce low frequency directivity. The principle, structure and shape of the loudspeaker system and the transmission characteristics of the sound wave determine the directivity. Because the principle and the characteristics of the sound wave cannot be changed, now people change the directivity by changing the shape and structure!

Why does linear array sound system have high sound pressure level and long transmission distance? The main reason is that the linear array audio system controls the directivity of high, medium and low frequency (how to control directivity is the key of the linear array audio system). To control directivity is to control the sound pressure level, and to control the sound pressure level is to control the attenuation characteristics and transmission distance. The relationship between the directivity of the sound source and the sound pressure level is shown in the figure. From the figure, we can see that when the directivity changes from 360 to 45 degrees, the sound pressure level increases by 6dB, and for the sound reinforcement distance, the distance is doubled. That's why we need to control directivity.

For the ordinary speaker system, the directional axis is shown in Figure 3, which is characterized by the vertical relationship between the directional axis and the speaker. The directivity greater than the structural dimension of the hoist system is 360 degree circle (lower frequency). If you want to adjust the directivity angle of the speaker system, you need to adjust the axis direction of the speaker, so it is more complex. Especially for linear array sound system, it is more complex. So in the current linear array sound system, there are many different installation forms, such as arc array, J array, etc., which are all to meet the requirements of directivity. Several installation methods of linear array sound system.

The formation of directivity is due to the interference of sound waves. If we can control the interference form of sound waves, then can't we control directivity? From the formation of the directivity of the linear array sound system in the figure, we can see that the directivity axis of the linear array sound system is vertical to the array when it is in the vertical state, and when the linear array sound system is in other states, the directivity axis deviates from the horizontal state, showing a certain angle with the ground.

Therefore, to change the directivity angle of the speaker system, we need to change the axis deviation angle of the speaker system. The relationship between the directivity angle of the linear array speaker system and the axis angle of the system) from the angle of deviation, we can see that the cumulative position deviation of the linear array speaker system from the top to the bottom of the speaker system. According to this phenomenon, we can delay a single speaker system to generate a virtual axis without changing the axis offset of the linear array speaker system, so that we can change the directivity angle of the linear array speaker system.