What are the advantages of using bi-amp drivers for speakers?
In the field of professional sound reinforcement, the traditional 2.1 multimedia speakers driving methods are the built-in crossover mode driven by a single power amplifier, which is only suitable for general applications. In modern sound reinforcement systems with high requirements and high power, bi-amplifier (bass power amplifier and mid-high frequency power amplifier) or triple-amplifier drive (high, medium and bass 2.1 multimedia speakers are driven respectively) are often used. Compared with the single-power amplifier driver, this matching method can avoid many shortcomings of the single-power amplifier driver, making the sound quality more pleasing to the ear.
1. Improve the damping coefficient of the 2.1 multimedia speakers system
The damping coefficient reflects the ratio of the 2.1 multimedia speakers impedance to the total impedance of the entire front-of-speaker circuit. The higher the damping coefficient, the more obvious the response of the output signal of the power amplifier to the 2.1 multimedia speakers, that is to say, the higher the control power of the power amplifier on the 2.1 multimedia speakers. The frequency division components used in the built-in frequency divider are all high-impedance components, so the power frequency division will greatly increase the total impedance of the circuit, thereby reducing the control power of the power amplifier and affecting the improvement of sound quality.
After using bi-amp or tri-amp drive, there is no built-in frequency divider circuit, so there is no adverse effect on the damping coefficient of the system.
2. Eliminate the insertion loss of the 2.1 multimedia speakers
The so-called insertion loss refers to the part of the power that is output by the power amplifier, but cannot be transmitted to the 2.1 multimedia speakers and converted into sound. The built-in frequency division is also called LC frequency division. Its principle is to use the low-pass and high-pass characteristics of the inductor (L) and capacitor (C) to prevent a part of the frequency signal from passing through a certain circuit, thereby completing the frequency division. However, the components such as inductors and cement resistors used in the built-in frequency divider are power components that consume a lot of energy. The energy lost on these components constitutes the so-called "insertion loss", and the more the frequency divider is complex, the greater the insertion loss will be.
After using bi-amp or tri-amp drive, since there is no third device between the output of the power amplifier and the 2.1 multimedia speakers unit, it can perfectly eliminate the insertion loss, that is, its utilization rate for the output energy of the power amplifier is significantly higher.
3. Better phase characteristics
In addition to the trouble caused by the internal resistance of the LC components of the power divider, the phase effects brought by them as the phase components also need to be carefully considered when designing the power frequency divider. For a 2.1 multimedia speakers, at different frequencies, the phase situation of the tweeter and the frequency divider is very complicated. If the phase problem is not considered when designing the frequency divider and appropriate phase compensation is made, it is likely to cause Although the frequency division attenuation of the tweeter and woofer is perfect, due to the inconsistent phase of the two, the curve is uneven, and even a 2.1 multimedia speakers with a perfect curve but poor phase, the sound is often better than no phase problem, but the curve is not too good, the ideal 2.1 multimedia speakers is much harder to hear.
After using bi-amp or three-amp drive, the circuit design of electronic frequency division is easier than the built-in frequency division in phase control, and the phase characteristic is much better than the built-in frequency division.
4. Drive power distribution is more accurate
After using bi-amp or tri-amp drive, each 2.1 multimedia speaker unit can obtain accurate driving power, give full play to their respective advantages and characteristics, and the sound quality is more pure and pleasant.
5. The crossover point and crossover characteristics are easier to control
2.1 multimedia speakers driven by bi-amp or tri-amp use integrated circuit active filter for frequency division. Before the amplifier, the sound signal is very weak, so it is easy to completely divide the sound, which can be easily adjusted by adjusting the input parameters. The crossover characteristics make up for the acoustic defects of the unit in a certain frequency band, and at the same time reduce the crossover area of the crossover, with good adjustability and improved electro-acoustic indicators.
6. Reduce modulation interference
For 2.1 multimedia speakers driven by a single power amplifier, the harmonic distortion and overload distortion of the woofer can be transmitted to the corresponding medium and high frequency 2.1 multimedia speakers units through the frequency division network, which increases the system distortion and the high frequency 2.1 multimedia speakers unit is easily damaged. After using bi-amp or tri-amp drive, the input of high frequency, intermediate frequency and low frequency is independent, which avoids the modulation interference of low frequency signal on high frequency signal in the transmission of "long" 2.1 multimedia speakers line, thus improving the quality of treble output. .
Therefore, after adopting the bi-amp or tri-amp drive mode, the sound distortion and power loss are reduced, and the perfect interpretation of the sound reinforcement quality is guaranteed.