1．话筒声反馈造成的自激啸叫声是歌厅和卡拉0K厅的常见现象，由于存在声反馈，一般扩音系统增益都不能很大。发生声反馈啸叫的原因是：
The 1 microphone acoustic feedback caused by self howling is a common phenomenon in karaoke bars and Cara 0K hall, because of the existence of the acoustic feedback, the general sound system gain are not great. The occurrence reason of howling is acoustic feedback:
(1)话筒距济南音响太近，话筒正向指向音箱；
(1) the microphone from the Ji'nan sound too close, positive directional sound box microphone;
(2)济南音响调音台上混响调节过大；
(2) Ji'nan audio console reverb adjustment is too large;
(3)话筒音量调节过大；
(3) the microphone volume adjustment is too large;
(4)没有接通压限器；
(4) not connected pressure limiter;
(5)厅内声学设计缺陷。
(5) the hall acoustics design defects.
2．针对以上原因可采取以下措施：
2 in view of the above reasons may take the following measures:
(1)为演唱者的活动舞台限定一个大致的范围，在此范围内不应发生啸叫声。也就是说，演唱者不应太靠近主音箱，主音箱应对称于舞台两侧；演唱者的站位不应使话筒正向指向音箱。
(1) as the singer's active stage of defining a general range, occurring whistlers should not within this range. That is to say, the singer should not be too close to the main sound box, the main speakers on both sides of the stage to deal with known; singer's stance should not make positive directional sound box microphone.
(2)歌厅的舞台应进行声学处理，墙面和两侧应装吸音材料。
(2) karaoke stage should be acoustic processing, wall and the two sides should be installed sound-absorbing material.
(3)接通压限器，其压缩比应设置为<=2：1，动作时间为10ms，释放时间为0．3s.
(3) connect the limiter, the compression ratio should be set to <=2:1, the action time is 10ms, the release time of 0.3s.
(4)济南音响 http://www.jnzqyx.com/ 调音台上的混响调节和音量不要开得过大。
(4) Ji'nan audio mixer on the reverb and volume do not open too big.
(5)以上措施不能奏效时，可通过调节均衡器，对易产生啸叫的频率加以衰减。
(5) the above measures don't work, by adjusting the equalizer, for easy to produce the howling of frequency of attenuation.
具体操作方法如下：
The following specific operation method:
将济南音响均衡器各频点位置先做好记录；然后，示范演。加大音量(用调音台总推子调节)，到系统刚好产生自激的位置，将均衡器上的调节钮从低频开始逐个下调，能够有效消除自激啸叫的频点，根据经验一般只有一个自激谐振频率(如250Hz)，此频率附近可下拉3—5dB，其余频点仍应保持原先记录的位。
Each frequency point position of Ji'nan audio equalizer to record; then, demonstration. Increase volume (adjusted by a mixer total fader), to the system just produce self position, the adjusting knob equalizer from the low frequency one by one down, can effectively eliminate the frequency of self-excited howling, according to experience in general only a self resonant frequency (such as 250Hz), the frequency near 3 5dB drop, the remaining frequency point should still maintain the original recording bit.