Power amplifier and audio power configuration
In the field of professional sound amplification, the configuration of sound equipment is very elegant, among which the configuration of power amplifier and sound box is the most important, although, some speaker products have recommended the specific brand or model of the power amplifier to the user, but there are still limitations, because users often face many models of power amplifier, there is no way to start. There are many aspects involved in the configuration of power amplifier and sound box, such as the brand of power amplifier, the choice of power tube type and which power amplifier should be configured for low-sensitivity sound box. Power amplifier and the specific configuration of the speaker are generally related to the designer's experience, hobbies, listening habits and other factors, it is difficult to find a unified standard. Sometimes we encounter some users or designers who often configure the speaker with a lower power in order to save money, some users have also configured the speaker with a high power amplifier for the so-called 'sufficient power Reserve. Obviously, it is not appropriate to do so. It is important that such a configuration will cause damage to the device. In the power amplifier and speaker configuration, power amplifier power is indeed the key, that is to say, the principle of determining power amplifier power should be unified. As we all know, after the acoustic design of the hall, it is necessary to determine the speaker power according to a series of calculations, and then determine the power amplifier power by the Speaker power, but how can the two powers be selected to achieve the best match? First of all, in the human ear listening domain of 20Hz ~ Within 20 kHz, music signals that really concentrate a large amount of energy are generally in the medium, low and frequency bands, while the energy in the high frequency band is only equivalent to 1/10 of the energy in the medium and low frequency bands. Therefore, the power lost by the treble of the general speaker is much lower than that of the bass speaker in order to balance the height and bass; The power amplifier is like a current regulator. Its input audio signal is controlled, and the current of different sizes is output to the Speaker to make the sound of different sizes. Under certain impedance conditions, it is actually very easy to make the power amplifier with a nominal power of 200W reach 400W or several times the output, but the distortion of the power amplifier (THD) This kind of distortion mainly produces high-frequency harmonics in medium and low frequency signals. The greater the distortion, the greater the high-frequency harmonic energy, these high-frequency distortion signals will enter the high-pitched head with the high-frequency music signal, which is why the low-power amplifier pushes the large speaker to burn the high-pitched head. In many people's concepts, as long as power amplifier has high power, it is possible to burn speakers. Although some power amplifier does not have distortion indication, distortion may occur during use due to the inherent shortage of equipment configuration, and distortion indication has lost its meaning. Moreover, due to the limitations of users' experience and quality, the distortion of power amplifier is often easily ignored. Secondly, the power amplifier has a certain relationship with the power configuration of the speaker and the target loudness and the occasion used. Under a certain target loudness, the dynamics of music signals should be fully guaranteed on every piece of equipment. If the power amplifier power is too large, its gain setting is very small and loudness has reached the requirements, however, the gain of power amplifier limits the dynamic range of the signal. Therefore, the power amplifier power cannot be too large; Otherwise, since spending is wasted, it will bring about the trouble that loudness and music dynamics cannot be balanced and speakers are overloaded. According to past experience, there are differences between general language, music amplification places and large dynamic discos. There is a general sound amplification place where the signal fluctuates little and does not need power amplifier to provide a large current to the speaker for a long time or soon, therefore, the power amplifier power should be smaller than that of a large dynamic amplification site requiring strong power; In addition, the so-called 'power reserve' should also be aimed at Speakers. It is worth noting that the selection of power amplifier must be determined by speakers, there should be no concept of 'power Reserve' to configure power amplifier. In other words, under a certain target loudness, the speaker can be larger than the design value for different purposes, and the power of power amplifier should be strictly determined by the speaker without much flexibility. In short, the specific standard for power amplifier and speaker power configuration should be: under certain impedance conditions, power amplifier power should be greater than Speaker power, but not too large. The non-distortion rate of power amplifier in general application places should be 1. 2-1. About 5 times; In the big dynamic situation, it should be 1. 5-About 2 times. With reference to this standard, since it can ensure that power amplifier works in the best state and the safety of the speaker, even for inexperienced operators, as long as it is not a serious operation error or improper adjustment of the previous peripheral equipment, the speaker and power amplifier can work in a stable state.