In the speaker frequency divider, there are only three main types of components: these are inductors, capacitors and resistors.
The role of the resistor is an attenuator, which is used to balance the sound ratio of each frequency band. As long as the power is large enough for selection. For the treble attenuation resistors of small speakers, it is better to use metal film resistors.
The role of the inductor is to filter out the treble and strobe the bass. In recent years, many kinds of inductance coils wound with special-shaped enameled wire have become popular. Among them are multi-stranded enameled wire, hexagonal enameled wire and ribbon enameled wire, etc. Every kind of inductance coil of special-shaped wire is said to have a certain magical power. But is this really the case? Actually it is not.
There are only three requirements for inductance coils for speakers. One is that the inductance is accurate; the other is that its own DC resistance is low; the other is that it is not easy to produce saturation distortion.
Regarding the accuracy of the value, as long as it is measured and calibrated with high-precision instruments one by one during the production process.
In order to reduce the self-resistance of the inductance coil, it is necessary to improve the conductivity of the enameled wire itself. The conductive ability of enameled wires and their cross-sectional area are inseparable and directly related to the cross-sectional shape. When the cross-section of the wire is round, square, or hexagonal, the efficiency is highest.
Specifically for winding inductors, the hexagonal cross-section enameled wire can effectively reduce the gap between the turns and improve the efficiency of the inductor. Especially for multi-layer coils with a large number of turns, the improvement effect will be very obvious. However, when hexagonal enameled wire is used, the production cost will also be greatly increased.
Therefore, if it is not used in very high-end occasions, the round oxygen-free copper enameled wire with a purity of 4N or more is used, and the effect is quite good. When choosing the wire diameter of the enameled wire, there is never a saying that the thicker the wire diameter, the better. As long as the inductance meets the requirements, the DC resistance is about one-tenth of the DC resistance of the woofer's voice coil. The DC resistance of the inductor is too large, which directly affects the low-frequency damping characteristics of the speaker; if the DC resistance of the inductor is too small, it will increase the production cost needlessly.
As for the choice of the frequency divider capacitor, there will never be a single capacitor that will fundamentally change the reproduction of the speaker. For friends who make their own speakers or want to improve the finished speakers, they must first have a clearer goal. When making speakers, the grade of crossover capacitor should be selected according to the investment of the speaker unit.
For example, if you buy a tweeter with a price of tens of yuan per unit, it is not worthwhile to spend another 20 yuan to choose a capacitor for it. You might as well buy a tweeter for one hundred yuan, and choose a crossover capacitor for a few yuan to get the benefit. If you have bought a tweeter for 300 yuan per unit, and spend dozens of dollars to buy a crossover capacitor, this is a good match.
For audio capacitors, different brands and materials have different effects on playback. But these inherent and detailed differences can be better reflected in the tweeter above the mid-range.
For the frequency division capacitors in the low frequency band, the main focus is on accurate capacitance, voltage resistance, and reliability. Compared with treble crossover capacitors, the requirements can be relatively lower, because high-end capacitors with large capacitance values are too expensive. Often in a state where the gains outweigh the losses after use.