As everyone knows, the capacitor (C) and the inductor (L) form the LC network (NETWORK) on the sound line. When the output signal of the crossover line-power amplifier (POWER AMPLIFIER) passes through this LC network, According to the designed crossover point and sound path, the high and low frequencies are separately sent to different speakers (such as TWEETER, MID-RANGE, WOFFER, SUB-WOOFER ...)
According to the design of the engineers of each factory, the LC network has the simplest two-way (2 WAY) high / bass, the common three-way (3 WAY) high / mid / bass, and the advanced four-way (4 WAY) High / medium / low / super bass or super high / high / medium / bass, to the top five-way (5 WAY) super high / high / medium / low / super bass, and even more channels
The circuit of the LC network is also designed according to the engineers of each factory. Each sound path has from the most basic one capacitor and one inductor, two capacitors and two inductors, to several capacitors and several inductors.
Because the signal passes through the capacitor and its phase is reversed by 90 degrees (if this capacitance is lossless-in fact, it is impossible), and when the signal passes through the inductor, its phase advances by 90 degrees, so in order to restore the signal phase to the original phase, Generally, the same number of capacitors and inductors must be used for each audio path of a complete crossover circuit (of course, some people insist on using different numbers as signal phase differences)
Because all sound passes through the LC network from the power amplifier to the speaker (unless it is a Yangchun type), the importance of these two components for sound cannot be ignored. It is also the same as the single speaker or speaker. For
The relationship between capacitor and sound:
Accurate crossover point and capacitor
As mentioned before, the LC network formed by the capacitor and the inductor is a frequency-dividing circuit, and its formula is
F (crossover frequency) = 2π√ (L x C)
Therefore, the frequency division frequency of the classification point is accurate, and the capacitance value of the capacitor is relatively accurate. Therefore, the error value of the capacitor used on the frequency division line is more accurate, such as ± 20% ± 10% ± 5% or even ± 2 % ± 1% both
Signal (SIGNAL) and capacitor polarity (POLARITY):
Because the output of the power amplifier is the signal voltage (also known as AC), the capacitor used on the crossover line must be "NON-POLARIZED" ·
Signal (SIGNAL) and capacitor withstand voltage (WV):
In order to carry the signal voltage output by the power amplifier, the withstand voltage of the capacitor used on the crossover line must be higher than the output signal voltage PP (PEAK-PEAK) designed by the power amplifier, which is generally 30% higher 40% is regarded as a safe value (there is no need to request an excessively high withstand voltage value to avoid unnecessary cost) · The signal voltage output by most power amplifiers does not exceed 30VAC, so it is sufficient to use a withstand voltage value of 50V, of course 100V withstand voltage is more safe
** The size of the power load (POWER) and the withstand voltage of the capacitor have no effect, but is related to the ripple current (RIPPLE CURRENT) of the capacitor, that is, the DISSPATION FACTOR.
Signal power (POWER) and capacitor loss angle:
In the above, the load-carrying power of the capacitor is related to the value of the loss angle. The lower the value of the loss angle, the greater the power. The higher the value of the loss angle, the smaller the power.
What is the loss angle (DISSPATION FACTOR-also referred to as DF)? The angle between the phase angle of the signal passing through the capacitor and -90 degrees is called the loss angle (DISSPATION FACTOR-also referred to as DF). The phase angle of a standard capacitor is negative 90 degrees (loss angle) Is zero, the ESR impedance value is also zero), and the lower the DF value, the lower the ESR impedance value ·
If the phase angle of a signal-passing standard capacitor is negative 90 degrees, the closer the capacitor phase angle is to -90 degrees, the lower the loss angle value, and therefore the greater the carrying power. If a standard capacitor is assumed, the phase is -90 Degrees, that is, the loss angle value is zero, and the ESR impedance value is also zero, so that it can carry infinite power.
Sound quality (TONE) and capacitor loss angle:
The loss angle value is proportional to the capacitor's graded series internal resistance (ESR). The lower the loss angle value, the lower the internal resistance value. The higher the loss angle value, the higher the internal resistance value. Therefore, the sound quality is good or bad. The angle quality is inversely proportional. The lower the loss angle value, the lower the internal resistance value. Therefore, the sound quality is better. The higher the loss angle value, the higher the internal resistance value, so the sound quality is worse.
Frequency response (FREQUENCY RESPONSE) and capacitor loss angle:
When the same capacitor works at different frequencies, its loss value and capacity value are different. Generally speaking, the higher the operating frequency, the greater the loss angle value (the smaller the capacity value). The magnitude of the change rate and this The loss angle value of the capacitance is proportional to the height. The lower the loss angle value, the smaller the change rate, and the higher the loss angle value, the greater the change rate. Therefore, the frequency response is closely related to the loss angle value of the capacitance. Low capacitors, because of the smaller change rate of loss angle value and capacity value when operating at various frequencies, the flatter the frequency response (the wider the frequency can be passed), the higher the loss angle value is.
** Most capacitors for frequency division can specify the highest loss angle value (for example, 10% 5% 4% 3% 1% ...) that the test frequency can be allowed under 120HZ or 1KHZ, but in order to make The frequency response is flatter for perfection (generally, the curve of high frequency or treble should not be pulled down), or the capacitor can be required to specify its test frequency at a higher frequency (such as 3KHZ 6KHZ 10KHZ or even 20KHZ, preferably It is the same frequency as the set crossover point) Set the highest allowable loss angle value and rated capacitance value-about this point, the professional audio capacitor manufacturer can cooperate to meet this requirement
SPEEDY OF TRANSMISION and loss angle of capacitor:
For example, the aforementioned loss angle value is directly proportional to the capacitor's graded series internal resistance (ESR). Therefore, in addition to the sound quality and loss angle value, the sound transmission speed is also closely related to the loss angle value. The lower the internal resistance value and the faster the transmission speed, the higher the loss angle value is.
It should be understood from the above that the quality of the capacitor is related to the audio speaker (whether it is for home or car). The capacitor is like the artery of the audio. The error value of the capacitor should be accurate, the withstand voltage value should be sufficient, and the loss angle should be low.
Briefly describe the capacitors used in various crossover circuits:
Types of capacitors and
Its highest DF value @ 1KHZ
General capacity range and
Tolerance value
Features
PP plastic film
0.04%-0.10%
0.01μF ~ 47μF
± 1% ~ ± 10%
Lowest loss angle, fastest speed, highest frequency
The clearest sound and the highest cost
Suitable for: UHF, high frequency, high power, top products
PE plastic film
0.4%-1.00%
0.1μF ~ 100μF
± 1% ~ ± 10%
Low loss angle, high speed, high frequency
Loud sound, high cost
Applicable to: high frequency, medium and high power, high-end products
Low-loss NP electrolysis
2% 3% 4%
5% 6% 10%
1μF ~ 300μF
± 2% ~ ± 10%
Low loss angle, high speed, medium and high frequency
Soft sound, moderate cost
Applicable to: mid-high frequency mid-high power premium products
General NP electrolysis
10% 12% 15%
1μF ~ 1000μF
± 10% ~ ± 20%
High loss angle, slow speed, low and medium frequency
Sound paste has the lowest cost
Applicable to: low power general grade products
CCTV Cables
Coaxial Cable,Coax Cable,BNC Cable,CCTV Pre-made Cable,DC power splitter
Chinasky Electronics Co., Ltd. , https://www.chinaskyswitches.com