How to Make a Speaker Crossover

Speakers Crossovers will be the main subject of the following content. Through this article, the editor hopes that everyone can have some knowledge and understanding of its relevant situation and information. The details are as follows.

1. How to make a speaker crossover

The speaker frequency divider, also known as the speaker wave splitter, can divide the mechanical wave into several bands. For example, the two-wave splitter is composed of a short-wave pass filter (short-pass filter) and a long-wave pass filter (long-pass filter). The three-wave splitter adds a band-pass filter. The wave splitter is the "brain" of the speaker and is crucial to the quality of the sound.

So, how to make a speaker crossover? The steps to make a speaker crossover are as follows:

Prepare materials: Inductor skeleton, enameled wire, resistors and capacitors (capacitors and resistors), adhesive, coins, bolts, copper-clad plates and transparent tape. Among them, it is best to use imported or domestic high-quality CBB capacitors for frequency division capacitors, and high-power cement resistors are preferred for resistors.

Winding the inductor: Choose a suitable inductor skeleton, such as solder wire, plastic skeleton of raw tape, wood, rubber skeleton, etc. Wind the enameled wire on the skeleton. Be careful not to touch the enameled wire with your hands during winding to avoid affecting the uniform coating of the enameled wire. After winding, wrap several layers of transparent tape tightly around the coil to fix it.

Prepare for component installation: Drill holes on the copper-clad board according to the positions of the inductor coil and resistor and capacitor, scrape the leads of the coil, capacitor and resistor clean, apply tin and solder them to the corresponding positions. Finally, solder the input and output wires on the board.

Connection circuit: For the tweeter, the current first flows through the capacitor to block the low frequency, allowing the high frequency part to pass first. The speaker is connected in parallel with the inductor, allowing the inductor to generate a negative voltage to provide voltage compensation for the tweeter. For the woofer, the current first flows through the inductor to block the high frequency part and pass the low frequency part. Similarly, a capacitor is connected in parallel to the speaker, using the voltage generated by the capacitor at high frequencies to compensate for the loss.

After completing the above steps, the speaker crossover is completed.

Second, the role of the speaker crossover

1. Make all speakers work in the most appropriate wavelength band

Speakers with different diaphragm sizes and materials have different optimal working wavebands. The longer (larger) the diameter of the speaker, the better the long-wave characteristics. Therefore, under the same other conditions, the long-wave effect of an 18-inch speaker is definitely better than that of a 15-inch speaker.

The better the rigidity and hardness of the diaphragm material, the better the short-wave characteristics of the sound. Many short-wave speakers use titanium or indium diaphragms as diaphragm materials to improve their short-wave characteristics; while the diaphragms of long-wave speakers are generally made of paper, carbon fiber, bulletproof cloth and rubber (edge) to facilitate long-wave reproduction.

Using a splitter, shortwave signals can be sent to shortwave speakers, medium-wave signals to medium-wave speakers, and long-wave signals to long-wave speakers. Short, medium, and long wave signals each go their own way, making the greatest possible use of the working wavelength advantages of each speaker to ensure that speakers in different working bands can play their full role and make the playback characteristics of each wavelength more balanced and consistent.

The loudspeaker has a large amplitude for long waves and a small amplitude for short waves. Theoretically, the amplitude of the loudspeaker cone is proportional to the square of the reproduced wavelength, that is, for the same loudspeaker diaphragm, under the same amplitude of signal voltage, the longer the wavelength, the greater the amplitude. In other words, if the wavelength increases 10 times, the amplitude will increase 10 squared, or 100 times.

If we use a loudspeaker to generate mechanical waves with a very wide wavelength range, it is very difficult to have very wide amplitude changes at the same time due to the limitations of the mechanical properties of the diaphragm. This will inevitably lead to the phenomenon of mechanical wave cutting and distortion, which will affect the reproduction quality to a certain extent.

Research has found that cutting distortion has the greatest impact on long waves. When a long-wave speaker broadcasts long waves, as long as there are short-wave components, it will inevitably cause cutting distortion, making the long waves appear unnatural. Of course, cutting distortion in short-wave speakers will also make short waves sound unnatural, but the impact is not as great as that of long waves.

2. Reduce the sound generated between different speakers in the same sound box

Interference phenomenon For the short-wave speakers and long-wave speakers in the short- and long-wave separated speakers, although their working bands are different, if the full-wave signal is sent to the short-wave speakers and long-wave speakers without adding the split wave, the short-wave speakers and long-wave speakers will definitely emit the same sound at the same time. When the same mechanical waves of different speakers meet, it is very likely that the sound waves will interfere with each other. Anyone with a little common sense in acoustics knows that once interference occurs, a series of problems will arise, such as comb filtering effect and standing waves. These problems will affect the good reproduction of mechanical waves to varying degrees.

After setting up the splitter circuit, the short-wave and long-wave speakers respectively obtain their own optimal working band signals, and the wavelength range of the mechanical waves emitted by them almost does not overlap. Except for a small amount of interference at the splitter point and the splitter intersection area of ​​the speaker, the interference phenomenon of other wavelengths no longer exists at all.

The reason why there is interference at the split point and the split cross area is very simple. Since the split attenuation rate of the splitter cannot be infinite, in the split cross area, especially at the split point, the short wave speaker and the long wave speaker will have mechanical waves of the other band at the same time, and interference is inevitable. Therefore, the higher the split attenuation rate of the splitter, the smaller the split cross area, and the smaller the interference between the speakers.