There are many aspects involved in the configuration of power amplifiers and speakers, such as power amplifier grades, selection of power tube types, and which power amplifiers should be configured for low-sensitivity speakers. The specific configuration of power amplifiers and speakers is generally related to the designer's experience, hobbies, listening habits and other factors. It is difficult to find a unified standard.
Sometimes we will encounter some users or designers who often configure speakers with smaller power amplifiers in order to save costs, and some users configure speakers with high power amplifiers for the so-called "sufficient power reserve". Obviously, this is inappropriate. Importantly, this configuration can cause damage to the device. In the power amplifier and speaker configuration, the power of the power amplifier is indeed the key, that is to say, the principle of determining the power of the power amplifier should be unified.
Everyone knows that after the acoustic design of the hall, the speaker power needs to be determined according to a series of calculations, and then the power amplifier power is determined by the speaker power, but how to match the power of the two to achieve the perfect match?
First of all, in the 20Hz~20kHz range of the human ear, the music signal that really concentrates a lot of energy is generally in the middle, low and frequency bands, while the high frequency band energy is only equivalent to 1/10 of the energy in the middle and low frequency bands. Therefore, the treble loss power of the general speaker is much lower than that of the woofer, in order to balance the high and low frequencies; and the power amplifier is like a current modulator. Under the control of its input audio signal, it outputs currents of different sizes to the speaker to make it happen. Different sounds, under certain impedance conditions, it is actually very easy to make a power amplifier with a nominal power of 200W reach 400W or several times the output, but the distortion (THD) of the power amplifier will be greatly increased. The high-frequency harmonics in the medium and low-frequency signals, the greater the distortion, the greater the high-frequency harmonic energy, and these high-frequency distortion signals will enter the tweeter together with the high-frequency music signal, which is why the low-power amplifier pushes Big speakers will cause the high-pitched head to burn. In the concept of many people, as long as the power of the power amplifier is high, it is possible to burn the speakers. Although some power amplifiers do not have a distortion indicator, due to the inherent insufficiency of the equipment configuration, distortion may occur from time to time in use, and the distortion indicator has no meaning at this time. Moreover, due to the limitation of the user's experience and quality, the distortion of the power amplifier is often easily ignored.
Secondly, the power configuration of amplifiers and speakers also has a certain relationship with the target loudness and the occasion of use. Under a certain target loudness, the dynamics of the music signal should be fully guaranteed on each piece of equipment. If the power of the power amplifier is too large and the gain setting is very small, the loudness has reached the requirement, but the gain of the power amplifier is limited at this time. Dynamic range of the signal. Therefore, the power of the power amplifier should not be too large; otherwise, since the expenditure is wasted, it will bring the trouble that the loudness and music dynamics cannot be taken into account and the speaker is overloaded. According to past experience, there are differences between general language, music amplification venues, and dynamic discos. In general sound reinforcement places, the signal fluctuations are small, and it is not necessary for the power amplifier to provide a large current to the speakers for a long time or quickly, so the power of the power amplifier should be smaller than that of the strong and powerful large dynamic sound reinforcement places; in addition, the so-called "power reserve" "It should also be aimed at speakers. It is worth noting that the selection of power amplifiers must be determined by speakers, and there should be no concept of "power reserve" to configure power amplifiers.
In other words, under a certain target loudness, the speaker can be larger than the design value for different purposes, while the power of the power amplifier should be strictly determined by the speaker without much flexibility. In short, the specific standard for the power configuration of the power amplifier and the speaker should be: under a certain impedance condition, the power of the power amplifier should be greater than the power of the speaker, but not too large. In general applications, the undistortion rate of the power amplifier should be about 1.2-1.5 times the rated power of the speaker; in large dynamic situations, it should be about 1.5-2 times. According to this standard for configuration, since it can ensure that the power amplifier works under normal conditions, it can also ensure the safety of the speakers. Even for inexperienced operators, as long as it is not a serious operation error or improper adjustment of the front-end peripheral equipment, the speakers can be And the amplifier works in a steady state.
