Louder speaker burnout has always been a headache for sound protection personnel, whether it is in KTV, or in a bar or stage. After all, what are the factors that cause the speakers to burn out? Some of the more common factors are summarized below.
1 The speaker and power amplifier configuration is unreasonable
Many people who play audio will think that the output power of the power amplifier is too large, which is the damage factor that forms the tweeter. This is not the case. In professional situations, the speaker can usually accept a large signal impact that is twice the rated power, and can instantly accept a peak impact that is 4 times the rated power without any doubt. Therefore, under normal operating conditions, the rated output power of the power amplifier should be 1-2 times the rated power of the speaker to ensure that the power amplifier does not form distortion at the maximum power of the speaker.
2 Division frequency is not used properly
The improper use of the input crossover point when the external crossover occurs, or the unreasonable scale of the speaker operating frequency is also a factor that causes the damage to the tweeter. When using the frequency divider, the frequency division point should be selected strictly according to the speaker operating frequency scale provided by the manufacturer. If the crossover point of the tweeter is selected too low and the power load is too heavy, it is very easy to burn the tweeter.
3 Improper tuning of the equalizer
The adjustment of the equalizer is also crucial. The frequency equalizer is set up to compensate for the various shortcomings of the indoor sound field and the uneven frequency of the louder speakers. It should be debugged with a practical spectrum analyzer or other instruments. The transmission frequency characteristics after debugging should be relatively flat within a certain scale. If the bump frequency is increased by more than 10dB compared with the midrange frequency, not only the phase distortion formed by the equalizer will severely stain the music sound, but also the sound tweeter will be burnt down very simply. This type of situation is also the main factor in burning the louder speaker.
4 Volume adjustment
The attenuation knob of the power amplifier attenuates the input signal. If the input of the power amplifier is attenuated by 6dB, it means that to maintain equal volume, the front stage must output 6dB more, the voltage should be doubled, and the input upper dynamic The amount will be cut in half. At this time, if there is a sudden large signal, the output will be overloaded 6dB early, showing a clipping waveform. Although the power amplifier is not overloaded, the input is a clipped waveform, the treble is too heavy, not only the treble is distorted, but the tweeter may also burn out.
5 Incorrect selection of low-cut causes damage to the low-sound unit
Many tuners don’t pay much attention to low-cut questions. Originally, this low-cut is the greatest risk of damaging the low-sound unit. Many low-sound speakers can’t restore some ultra-low frequencies very well. When converting the ultra-low frequency component signal, due to the limited volume of the cabinet, the heat dissipation is not timely, and a large amount of heat gathers. Once the glue is unacceptable, it will melt, causing the bounce to fall off, the voice coil is scattered, and the louder speaker is damaged. The use of low-cut can greatly reduce the damage of ultra-low frequency to the low-pitched speaker.
6 The difference in input sensitivity when using different power amplifiers together
The question of the input sensitivity of the power amplifier is also a factor that causes the speaker to burn out. Equal power, different types of power amplifiers may have inconsistent sensitivity and voltage, which will cause damage to the speaker unit connected to the overload signal. When power amplifiers with the same power and different sensitivity voltages are mixed, the input level of the power amplifier with high sensitivity should be attenuated. It can be consistent by adjusting the output level of the front-end equipment or reducing the input potentiometer of the power amplifier with high sensitivity.
7 Big signals are disconnected instantly, causing the whisper unit to freeze
In KTV, it is very simple to cut the song or mute the sound under the state of high sound pressure, and the voice coil clamp of the bass unit may be burned. The audio signal is input to the horn through the electric current method, and the horn is moved forward and backward through the electromagnetic force to push the paper cone to make the air oscillate into a sound. When doing a large movement, the signal input is suddenly cut off. It is very simple to cause the unit to lose its recovery ability after the extreme movement. damage.
8 Pre-stage, the components of the power amplifier are self-excited
Some circuits of the front-end output are broken down, resulting in sine wave pure tone frequency output, similar to some frequency howling, and the output power is very large, which can directly cause the coil of the low-sound unit to burn due to power overload. The power amplifier becomes a DC output due to current breakdown, so that the concave and convex sound units of the louder speaker are damaged.