Power Configuration Of Amplifier And Speaker

- Jun 19, 2018-

In the field of professional sound reinforcement, the configuration of the audio equipment is very elegant, and the configuration of the power amplifier and the speaker is the most important. Although some of the speaker's raw product instructions indicate to the user the specific brand or model of the amplifier, but There are still limitations, because users often face many models of power amplifiers, no way to start. There are many aspects involved in the configuration of amplifiers and speakers, such as the selection of power amplifier grades, power tube types, and what type of amplifier should be configured for low-sensitivity speakers. The specific configuration of the amplifier and speaker is generally related to the designer's experience, preferences, listening habits and other factors, and it is difficult to find a unified standard.

Sometimes we will encounter some users or designers to configure the amplifiers with lower power amplifiers in order to save expenses. Some users configure large power amplifiers for the speakers for the so-called “power reserve”. Obviously, this is not appropriate. Importantly, this configuration can cause damage to the device. In the amplifier and speaker configuration, power amplifier power is indeed the key, that is, the power amplifier power determination principle should be uniform.

As we all know, after the acoustic design of the hall, we need to determine the speaker power based on a series of calculations, and then determine the amplifier power from the speaker power. However, how can the two powers be matched to achieve the best match? First of all, in the 20Hz to 20KHz of the human ear listening domain, the music signals that really concentrate a large amount of energy are generally in the medium, low, and frequency bands, and the high-frequency band energy is only equivalent to 1/10 of the energy in the middle and low frequency bands.

Therefore, the general speaker treble loss power is much lower than the bass speaker, in order to balance the bass and bass; and the power amplifier is like a current modulator, which controls the input audio signal, the output of different sizes of current to the speaker, so that the size of Different sounds, under certain impedance conditions, it is actually very easy to make 400W or several times the output power of a nominal 200W power amplifier, but the distortion (THD) of the power amplifier will be greatly increased. This kind of distortion is mainly caused by the high-frequency harmonics in the medium and low-frequency signals have higher distortion, and the higher the harmonic energy of high frequencies, these high-frequency distortion signals will all enter the tweeter together with the high-frequency music signals. This is why the low-power amplifier pushes. Large speakers can cause high pitchers.

In many people's concepts, as long as the power amplifier is large, it is possible to burn the speakers. Although some amplifiers have no indication of distortion, distortion may occur during use because the device configuration is already inherently inadequate. At this point, the distortion indication has lost its meaning. Moreover, due to the limitations of the user's experience and quality, distortion of the amplifier is often easily overlooked. Secondly, there is a certain relationship between the power configuration of the amplifier and speaker and the target loudness and the occasions used.

Under a certain target loudness, the dynamics of the music signal should be fully guaranteed on every piece of equipment. If the power of the amplifier is too high, the gain is set to be small, the loudness has reached the required level, but the dynamic range of the signal is limited by the gain of the amplifier. Therefore, the power amplifier power cannot be too large; otherwise, since the waste of expenses, it will bring loudness and music dynamics cannot take into account and the speaker overload.

Based on past experience, there are differences between places such as general languages, music venues, and big dynamic discos. There are generally small fluctuations in the signal in a public amplifying place, and it is not necessary to provide a large amount of current to the speaker for a long time or very quickly. Therefore, the power of the amplifier should be lower than that required for a strong and powerful large dynamic amplifying place; in addition, the so-called “power reserve” "It should also be noted that for speakers, it is worth noting that the choice of amplifier must be determined by the speaker, and there should not be a concept of "power reserve" to configure the amplifier.

In other words, under a certain target loudness, the speaker can be larger than the design value to prepare for different purposes, and the power of the amplifier should be determined strictly by the speaker, without much flexibility.

In short, the specific criteria for power amplifier and speaker power configuration should be: under certain impedance conditions, power amplifier power should be greater than the speaker power, but not too much. The undistorted ratio of a power amplifier in a general application location should be about 1.2-1.5 times the rated power of the speaker; and in a large dynamic application it should be about 1.5-2 times. Refer to this standard for configuration, since you can ensure that the amplifier works in the best condition.



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