FAQ
FAQ

The sound system is the lowest in the whole system.

The sound system is the lowest in the whole system.
Often see a certain brand of high - red coupling capacitance to connect the former pole and pole, due to the use of such a high level of capacitance, the value of the attack is also enhanced.
Some DIY attack on the board, because it is DIY, so what kind of costs are not considered. So a little of board also suddenly appears two huge coupling capacitor.
Some comments are also thought to be more advanced coupling capacitors to bring better sound.
Generally speaking, because of the capacitance performance is very good, so the volume is also large, the general can only use the capacity of a number of 1 micro method, and then the volume is too large.
I will here said: please put the capacitance change into 10 micro method or more large capacity of small capacitance, such as 22 micro method or 47 micro method for the non polarity or electrolytic capacitor, or 10 micro method of ceramic capacitors. The benefits of doing so are:
1, better low frequency,
2, smaller volume, lower noise and interference,
3, lower cost
4, is not good, but the high frequency part of the absolute will not have any loss than the original.
The bulk of the coupling capacitance is like an antenna that can be more introduced into the interference, leading to noise. And the circuit board is also bigger, longer, and there will be antenna effect. The small volume of the coupling capacitance itself as well as the circuit design can also reduce the interference.
As for bass better, it is obvious that the coupling capacitance as well as the load impedance form a high pass filter, with a greater capacity corresponding to a linear decrease of the cutoff frequency. Assuming that the load input impedance is 10 ohm, the coupling capacitance using the 1 micro method, 3dB as the frequency is about 15Hz. Since it is a first order high pass, the frequency of the signal has been reduced to a few tens of Hz, the reduction of the low frequency is bad, and the increase of the coupling capacitor can improve the problem.
The vast majority of people are worried about the low coupling capacitance will loss performance in high frequency, which is many senior agreed worry. I want to here said capacitor is originally, the higher the frequency, the lower the capacitance. Why high frequency but not easy to pass it?
Some interpretation is a general and low capacitance, high frequency performance difference is due to the non ideal characteristics of the capacitor, such as distributed inductance, high frequency resistance effect, etc..
But in the sound circuit, the load of the coupling capacitor is always high impedance, if it is a low impedance, the circuit is no longer a coupling circuit, but the frequency divider circuit. Frequency divider circuit on the characteristics of the capacitor is indeed relatively high, but not in the scope of the discussion.
Because the load is high impedance, such as 10K ohm. Due to the capacitance performance is not high and in some of the audio frequency band produced inductance and resistance characteristics, such characteristics of impedance will reach 100 ohm so great? Maybe a bad capacitor will have this effect make one's hair stand on end. If there is a change in the reactance of 100 ohm, the final cause of the change in the audio amplitude is only about 1%, so the difference is not likely to be heard. Moreover, this is the worst case make one's hair stand on end. Of course, there is a very simple way to improve the method is a relatively small capacity of the capacitor, to compensate for the main coupling capacitance in the vicinity of certain frequency fluctuations in the characteristics of the abnormal reactance. As to why not and the UN General Assembly, it is to avoid some of the two capacitance between the distribution parameters of the oscillation, and the frequency of the shock fell into the audio range.
For this post, we can change the idea to explain: the capacitance performance requirements and the need to pass the energy (virtual current), of course, more closely related to the operating frequency. The coupling capacitance is very light and the energy is very small, so it is very low to the capacitance. The frequency dividing circuit of the active frequency dividing circuit is relatively heavy, and the characteristics of the capacitor are relatively high. And the speaker of the frequency of the frequency of the power divider is very large, the requirements for the performance of the capacitor is also very high. Power filter capacitor transfer of energy is also relatively high (virtual current is relatively large), so the requirements are relatively high, but because of the operating frequency is not very high, high frequency characteristics of its requirements are relatively low, but switching power supply is not the same.
Another way of thinking is: when a sound circuit system to the characteristics of a capacitor is more concerned with the characteristics of the capacitor and other circuit filter characteristics of the tilt of the curve, the characteristics of the capacitor is relatively high. For example, the frequency of the capacitor, the sound system is concerned with the capacitance and other components of the filter characteristics, so the higher requirements. For the coupled capacitor, the system does not consider the performance of the filter characteristic curve on the cut-off frequency, because the frequency is usually outside the ear and the system requirements. Unfortunately, due to some design of the coupling capacity is too small, as the frequency of the move, the frequency characteristics of the system falls into the scope of the system, so the requirements for the performance of the capacitor is also improved. In simple terms, the poor design (the small capacity of the coupling capacitance) leads to poor performance (low frequency attenuation), and increases the cost of the component performance requirements (which have to be used in expensive capacitors).
When the capacity is chosen, the influence of different coupling capacitors on the sound is mainly reflected in the low frequency attenuation, which is different from the low frequency attenuation caused by the same nominal value.
I have tested a finished HIFI DIY attack, the use of 1UF's red WIMA coupling capacitor, after calculation, as of the frequency of up to about 20 Hz. After 10