How to choose speakers and power amplifiers in LED display screens?
How to choose speakers and power amplifiers in LED display screens?
In the field of professional sound reinforcement, the configuration of audio equipment is very particular, among which the configuration of power amplifiers and speakers is the most important. However, users are often faced with many brands and models of power amplifiers and have no idea where to start.
In fact, in the field of LED display applications, users do not need to pay too much attention to the importance of sound effects. Because the configuration of power amplifiers and speakers involves many aspects, such as the choice of power amplifier brand, power tube type, and which power amplifier 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.
And sometimes we encounter some users who often configure smaller power amplifiers for their speakers in order to save money, and some users configure their speakers with very high power amplifiers for the so-called "sufficient power reserve". Obviously, this is inappropriate. Importantly, such a configuration can cause damage to the device.
In addition, with the unanimous call of the public to create a green environment, noise pollution has always been a matter of great concern to society. In many residential areas, noise exceeding a certain decibel is not allowed. Even in bustling cities, relevant broadcasting equipment must be turned off at eight or nine o'clock at night. In more stringent places, loudspeakers are completely prohibited from playing.
So, in streets or squares where audio can be played in conjunction with LED display screens, is the sound effect important?
First of all, within the 20Hz~20kHz range of the human ear, music signals that really concentrate a lot of energy are generally in the mid- and low-frequency bands, while the energy in the high-frequency band is only equivalent to 1/10 of the energy in the mid- and low-frequency bands. Therefore, the high pitch of ordinary speakers cannot be expressed in an open environment, let alone other noisy sounds. It is almost difficult for the human ear to evaluate the high and low sounds by hearing; and especially for the sake of aesthetics, some users hide the speakers inside the large LED screen to muffle the sound inside. As everyone knows, even if a few honeycomb holes are opened, it will still be the same. Has no effect.
Secondly, the power amplifier is like a current modulator. Under the control of its input audio signal, it outputs currents of different sizes to the speakers, causing them to produce sounds of different sizes. Under certain impedance conditions, if you want a power amplifier with a nominal power of 200W It is actually very easy to achieve an output of 400W or several times, but the distortion (THD) of the power amplifier will be greatly increased. This distortion is mainly produced by high-frequency harmonics in medium and low-frequency signals. The greater the distortion, the higher the high-frequency harmonics. The greater the energy, and these high-frequency distortion signals will enter the tweeter together with the high-frequency music signal, which causes the tweeter to burn when a small-power amplifier pushes a large speaker.
Thirdly, the power configuration of the amplifier and speakers also has a certain relationship with the target loudness and the usage occasion. 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 at this time the gain of the power amplifier is limited. The dynamic range of the signal.
Therefore, the power of the power amplifier cannot be too large; otherwise, it will not only waste money, but also cause troubles such as the inability to take into account the loudness and music effect and the overload of the speakers. Based on past experience, generally speaking, there are differences between music amplification venues and large dynamic discotheques. In general, the signal fluctuations in amplification places are small, and the power amplifier does not need to provide a large current to the speakers for a long time or very quickly, so the power of the power amplifier should be smaller than that in large dynamic amplification places that require strong power;
In addition, the so-called "power reserve" should also refer to the speakers. It is worth noting that the selection of the power amplifier must be determined by the speakers, and there should not be the concept of "power reserve" to configure the power amplifier.
In short, the specific standard for the power configuration of power amplifiers and speakers should be: under certain impedance conditions, the power of the power amplifier should be greater than the power of the speakers, but not too large. In general applications, the distortion-free rate of the power amplifier should be about 1.2-1.5 times the rated power of the speaker; while in large dynamic situations, it should be about 1.5-2 times. Then, two 100W sound columns should use a power amplifier of 100*2*1.2=240W to 100*2*1.5=300W.
Configuring according to this standard can ensure that the power amplifier works in the best condition and ensures the safety of the speakers. Even for inexperienced operators, as long as there are no serious operating errors or improper adjustment of the front-end peripheral equipment, the The speakers and amplifier are working in a stable state.
In fact, in the field of LED display applications, users do not need to pay too much attention to the importance of sound effects. Because the configuration of power amplifiers and speakers involves many aspects, such as the choice of power amplifier brand, power tube type, and which power amplifier 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.
And sometimes we encounter some users who often configure smaller power amplifiers for their speakers in order to save money, and some users configure their speakers with very high power amplifiers for the so-called "sufficient power reserve". Obviously, this is inappropriate. Importantly, such a configuration can cause damage to the device.
In addition, with the unanimous call of the public to create a green environment, noise pollution has always been a matter of great concern to society. In many residential areas, noise exceeding a certain decibel is not allowed. Even in bustling cities, relevant broadcasting equipment must be turned off at eight or nine o'clock at night. In more stringent places, loudspeakers are completely prohibited from playing.
So, in streets or squares where audio can be played in conjunction with LED display screens, is the sound effect important?
First of all, within the 20Hz~20kHz range of the human ear, music signals that really concentrate a lot of energy are generally in the mid- and low-frequency bands, while the energy in the high-frequency band is only equivalent to 1/10 of the energy in the mid- and low-frequency bands. Therefore, the high pitch of ordinary speakers cannot be expressed in an open environment, let alone other noisy sounds. It is almost difficult for the human ear to evaluate the high and low sounds by hearing; and especially for the sake of aesthetics, some users hide the speakers inside the large LED screen to muffle the sound inside. As everyone knows, even if a few honeycomb holes are opened, it will still be the same. Has no effect.
Secondly, the power amplifier is like a current modulator. Under the control of its input audio signal, it outputs currents of different sizes to the speakers, causing them to produce sounds of different sizes. Under certain impedance conditions, if you want a power amplifier with a nominal power of 200W It is actually very easy to achieve an output of 400W or several times, but the distortion (THD) of the power amplifier will be greatly increased. This distortion is mainly produced by high-frequency harmonics in medium and low-frequency signals. The greater the distortion, the higher the high-frequency harmonics. The greater the energy, and these high-frequency distortion signals will enter the tweeter together with the high-frequency music signal, which causes the tweeter to burn when a small-power amplifier pushes a large speaker.
Thirdly, the power configuration of the amplifier and speakers also has a certain relationship with the target loudness and the usage occasion. 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 at this time the gain of the power amplifier is limited. The dynamic range of the signal.
Therefore, the power of the power amplifier cannot be too large; otherwise, it will not only waste money, but also cause troubles such as the inability to take into account the loudness and music effect and the overload of the speakers. Based on past experience, generally speaking, there are differences between music amplification venues and large dynamic discotheques. In general, the signal fluctuations in amplification places are small, and the power amplifier does not need to provide a large current to the speakers for a long time or very quickly, so the power of the power amplifier should be smaller than that in large dynamic amplification places that require strong power;
In addition, the so-called "power reserve" should also refer to the speakers. It is worth noting that the selection of the power amplifier must be determined by the speakers, and there should not be the concept of "power reserve" to configure the power amplifier.
In short, the specific standard for the power configuration of power amplifiers and speakers should be: under certain impedance conditions, the power of the power amplifier should be greater than the power of the speakers, but not too large. In general applications, the distortion-free rate of the power amplifier should be about 1.2-1.5 times the rated power of the speaker; while in large dynamic situations, it should be about 1.5-2 times. Then, two 100W sound columns should use a power amplifier of 100*2*1.2=240W to 100*2*1.5=300W.
Configuring according to this standard can ensure that the power amplifier works in the best condition and ensures the safety of the speakers. Even for inexperienced operators, as long as there are no serious operating errors or improper adjustment of the front-end peripheral equipment, the The speakers and amplifier are working in a stable state.