Solution for public address power amplifier and speaker configuration

In the field of professional amplification, the equipment of audio devices is very particular, and the power amplifier and the equipment of the speaker are the most important. Although some speakers have introduced the detailed trademark or model of the amplifier to the user in the instructions for the use of raw speakers, there are still limitations, because the user often faces many models of power amplifier, there is no way to start.

Power amplifier and speaker equipment touch many aspects, such as the power amplifier trademark, power tube type selection and low sensitivity speaker should be equipped with what kind of power amplifier. Detailed equipment of amplifiers and speakers is generally related to the experience, preferences, listening habits and other elements of planners, it is difficult to find a consistent norm.

Sometimes we encounter some users or planners who often equip speakers with low power amplifiers to save money, and some users who equip speakers with high power amplifiers for so-called "sufficient power storage". Obviously, this is not appropriate. The important thing is that such equipment will cause damage to the equipment. In power amplifier and speaker equipment, power amplifier power is really the key, that is, the power of the power amplifier should be consistent with the criteria.

As we all know, after the auditorium acoustic planning, the need for a series of accounting to determine the speaker power, and then the speaker power to determine the power amplifier, but ultimately how to choose the two power to achieve the best match?

First of all, within 20 Hz to 20 kHz of the human ear, the music signals that really gather a lot of energy are generally in the middle, low and high frequency bands, while the high frequency band energy is only equivalent to 1/10 of the medium and low frequency bands energy. Therefore, the loss of power in loudspeakers is much lower than that in low-pitched speakers, in order to balance the high and low sounds; and power amplifiers, such as a current modulator, under the control of its input audio signal, output different sizes of current to the speakers, so that they produce different sizes of sound, under certain impedance conditions, in order to let the nominal power 20. The output of a power amplifier of 0W up to 400W or several times is actually very simple. The distortion of a power amplifier (THD) alone will be greatly added. This distortion mainly produces high-frequency harmonics in the middle and low frequency signals. The greater the distortion, the greater the high-frequency harmonic energy, and these high-frequency distorted signals will enter the high-pitch along with the high-frequency music signals. This is why the small power amplifier pushes the big speakers to cause the burning of high pitched heads. In the concept of many people, it is possible to burn the loudspeaker only if the power amplifier power is large. Although some amplifiers have no distortion indication, the distortion indication has lost its meaning because the equipment is already congenitally inadequate and may occur during operation. Moreover, due to the user's experience and the constraints of the nature, the distortion of the power amplifier is often simply neglected.

Secondly, there is a certain connection between the power amplifier and the loudspeaker's power equipment and the loudness of the policy as well as the occasion used. Under certain policy loudness, the dynamic of the music signal should be fully assured in each device. If the power amplifier is too large, its gain setting is very small, the loudness has reached the requirements, but the gain of the power amplifier constrains the dynamic range of the signal. Therefore, the power of the amplifier should not be too large; otherwise, the expenditure will be wasted, and the loudness and music dynamics will not be able to co-ordinate as well as the speakers overloaded. According to past experience, there are differences in general speech, music amplification and dynamic auditorium. In general, amplifier power should be lower than that in large dynamic amplifiers where strong and powerful amplifiers are required. In addition, so-called "power storage" should also be targeted at speakers. It should be noted that the power amplifier must be selected by the sound. The box resolution should not have the concept of "power storage" to equip power amplifiers.

In other words, the loudspeaker can be larger than the planned value for different purposes at certain policy loudness, and the power of the amplifier should be determined strictly by the loudspeaker, without much flexibility. In conclusion, the detailed specification of power amplifier and speaker power equipment should be: under certain impedance conditions, power amplifier power should be greater than speaker power, but not too large. The undistorted rate of power amplifier in general application should be about 1.2-1.5 times of the rated loudspeaker power, while it should be about 1.5-2 times in large dynamic situation. Equipment in accordance with this specification can ensure that the amplifier works under the best conditions and the safety of the speakers. Even for inexperienced operators, the speakers and amplifiers can work in a stable state without serious operational errors or inappropriate adjustment of peripheral equipment at the front level.