如何解决麦克风啸叫

麦克风的声音系统拾取声音，都有反馈啸叫的可能性

麦克风啸叫的风险很高，主要在以下区域：

1.自激功率放大器会产生较大的输出，可能超出扩声设备的范围，烧坏放大器和扩声设备

2.当反馈系数接近1点钟时，由于梳状滤波器效应，延迟声场和直接声音之间的叠加会使声场在声音意义上比原始声场更窄。

3.扬声器声场延迟反馈，会使所有系统构成一系列连续的延迟响应，而这种响应会加剧梳状滤波器效应，产生失真的混响尾部刚刚响起。

4.嚎叫声压的输出非常大，严重影响了各种活动的气氛。

要消除反馈啸叫，从需要产生反馈啸叫开始，只要能够粉碎这一前提，就可以实现目标。

分配间隔的方法不仅是为了避免啸叫，而且为了提高放大音量，最有效的准备之一是使麦克风尽可能靠近声源，而麦克风应在没有方向性的情况下使用。这里要理解的是，指向麦克风（尤其是尖锐的指向麦克风）远声源的声音衰减很小，调整间隔以提高放大音量并避免啸叫。声音放大系统不容易发出啸声，麦克风的移动程度也不直接相关。只有麦克风的度数不太高才是尖锐的自然点，容易产生啸叫声。缩短可听设备和听众之间的距离实际上可以提高放大的响度。可以适当地降低系统的总增益。

如果伴随着定向宽近场扬声器，麦克风稍微远离该点可以避免啸叫。对于扬声器的直接反馈声场，麦克风离扬声器越远，扬声器离听众越好。

The microphone should be placed on the back of the target of the speaker's radiation, and if the microphone is likely to be held around, the speaker should be placed in a place where the microphone is not near.

Frequency equalization Method (Wideband notch method) Because the microphone pickup and sound equipment frequency curve is not an ideal flat straight line (especially some of the poor quality of the playback equipment), and the acoustics of the acoustic resonance of the auditorium, so that the frequency response fluctuation is very large.

It can compensate the sound amplifying curve with frequency equalizer, adjust the frequency response of the system to approximate straight line, so that the gain of each frequency band is consistent and the sound transfer gain of the system is improved. The equalizer should be used more than 21, and the parameter equalizer should be constructed at higher requirements, and the feedback filter can be adopted when higher requirements are required.

In fact, when the sound reinforcement system presents the feedback self-excited, its frequency is only a pure tone fixed at a certain point, so the system howling can be restrained if the frequency is removed by a narrow band trap.

Third, feedback filter method (narrow band notch method) In high demand occasions, such as some live singing premises, all over the use of audio feedback active restrain assembly, such assembly can actively track the frequency of feedback points, the active transfer of Q-value bandwidth, active voice feedback to eliminate and maximize the protection of the sound quality. The reason is that through the process of trapping waves to restrain howling. For example, Sabine's FBX series Feedback Actuator, it is a microcomputer-controlled 9-segment narrow band active compression assembly, can better identify the feedback self-excitation signal and music signals, can be in the system when the self-excited, agile response, and in the feedback frequency point set a very narrow digital filter, The notch depth is also actively set, and the filter bandwidth is only 1/3 times times the frequency, so narrow the notch band, almost does not affect the loudness and timbre