How does a crossover work? What is the use of an electronic crossover?

Electronic crossover is a type of crossover. Its main function is to set the frequency path of the signal part. Today we will learn about the function and operation of electronic crossover.

Electronic crossover

Electronic crossover is also called active electronic crossover. Its main function is to set the frequency of the signal part. It can be said to be a very basic equipment for a relatively complete and large system structure. The principle of active electronic crossover is to transmit the appropriate frequency signal to the appropriate unit. Because the speaker unit cannot output the full frequency of 20-20000Hz at present, we can only divide the unit into several partial frequency bands and then string them together. Transmitting the appropriate frequency to the appropriate unit can protect the unit and effectively utilize power. Each unit has its own suitable frequency band. If each unit is sent a full-frequency signal, it may cause damage to the unit and waste power.

The crossover slope of the electronic crossover is -6dB/Oct for the first order and -12dB/Oct for the second order. The so-called crossover slope refers to the extension of the frequency after the natural attenuation of the sound after the crossover point is set. The lower the slope, the longer the extension, and vice versa.

Active crossovers cut the signal before the post-amplifier, while passive crossovers cut the signal after the power amplifier. Therefore, active crossovers are more efficient in power utilization and can adjust the frequency more accurately. In terms of output voltage, most active crossovers can have a 5V output, which is the same as the 4V output of current high-end host computers, and can achieve better signal loss and greater dynamics.

The role of the crossover

The "function and use" of a passive crossover is between an amplifier and a speaker. Since a single speaker cannot achieve "full-band response" (full-band is 20HZ-20KHZ, the hearing range of the human ear), the physical bandwidth response of different speaker sizes is used to achieve the required "full-band response", which also leads to the use of multiple-sized speakers on the same channel. The function of a passive crossover is to divide the full-band output of the amplifier into sounds of different frequency bands and send them to speaker units of different sizes to show their due characteristics. The resulting multi-way speaker combination or "crossover speaker" has its uses and multiple choices from single-way car speakers to multi-way speakers.

Electronic crossover classification

1. Active crossover

It is also called active crossover network. Because the space in the car is limited, there are factors that cannot be changed in actual operation. The flexible characteristics of the electronic crossover can achieve the most ideal frequency adjustment in various bands to overcome the variable factors in the car and achieve the best listening environment in the car. It is installed between the car host and the amplifier. The active electronic crossover can be divided into several audio paths, but the audio path signals do not necessarily pass through the amplifier. However, the more audio paths are divided, the more amplifiers will be used. Its advantages are that it can improve the dynamic range and performance, so that the subwoofer can get the best power and the monomers are not easily controlled.

2. Passive crossover

Also known as a passive frequency division network, it consists of many components: L inductor, C capacitor, R resistor. They are the characteristics of frequency division flexibly applied to the passive frequency division network, so it is a complicated task.

There are four most commonly used slopes for passive crossovers: 6dB first-order slope, 12dB second-order slope, 18dB third-order slope, and 24dB fourth-order slope. The advantage of passive crossovers is that they can be used as independent individuals in a multi-channel system, and changes in each component can directly affect its characteristics.

How to operate the crossover

Generally, the electronic crossovers sold in the market are divided into 12dB, 18dB, and 24dB, and are also divided into high-pass and low-pass 2-way, two high-pass and low-pass 2-way, and high-mid-pass and low-pass 3-way. The larger the dB, the higher the grade, the cleaner the frequency comes out of the speaker, the less overlap, the smaller the slope, the higher the dB, the faster the frequency speed, and the speaker can withstand more power, which is helpful for height. For example, if we have a speaker and use a low dB crossover, then its tail frequency will be particularly long. Because those tail frequencies that are not needed in the sound are not filtered out, they need the power of the amplifier to drive them. The jump of the speaker is not so accurate, the slope is also large, and the power is wasted.

Passive crossovers use parts to change the frequency crossover point. If you make a standard crossover for this unit, other units may not be suitable. Active crossovers do not have this problem. However, we should note that the car itself is also a speaker, and there are problems with disassembly and phase, so the higher the dB, the less ideal it may be. It is better to install the whole system in the car, and then use the high and low dB to match the high, medium and low frequencies when the sound comes out. Sometimes the treble will use 18dB, the midrange 6dB, and the bass 12dB to make the whole sound field perfect. There is a champion car in the United States, its bass is 100HZ12dB crossover point, and the high pass is 400HZ6dB crossover point. The frequency is very average when tested with a spectrum analyzer (RTA).