News information

Why are some people interested in coaxial technology? Here's why!

2020.02.24

In the history of loudspeaker development, coaxial loudspeaker has been very small phase distortion and acoustic interference, accurate sound field positioning, and extraordinary analytical power and other characteristics of the industry with great interest, but also known as the "diamond in the crown of the speaker." Today, we will learn about those things about coaxial speakers, and see why some people have a soft spot for !

First、 what is a coaxial speaker

The so-called coaxial speaker is to use a coaxial speaker unit to replace the general 2-frequency speaker. The coaxial horn unit uses the energy exchange technology that puts the treble drive component and the bass drive component on the same axis to ensure that the acoustic center of the high and low is the same point, and the audio signal is obtained through a path, which can restore the sound to the maximum extent, synchronize transmission, and accurately locate.

We know that with the current horn energy exchange principle, the general drive components including diaphragm, magnetic steel, magnetic circuit design, voice coil materials, etc., it is difficult to meet the sound recovery of the entire audio range at the same time. Therefore, there is a high-frequency horn unit (or tweeter head) suitable for high-frequency signal recovery, a woofer unit suitable for low-frequency signal recovery, and some also have a medium-frequency horn unit. These different frequency band speaker units each perform their duties, combined in a box, you can better restore the sound of the entire audio range, which has become the widely used 2 or 3 frequency speaker.

The 2-division or 3-division structure only reduces the frequency distortion of the speaker, that is, the sound signal of the entire audio range can be better restored. But the problem is that the size of the 2 or 3 speaker units and the position of the drive components are not the same, and they are arranged up and down or left and right on the front barrier of the speaker. We carefully analyze, we will find that the treble or bass unit is sounded as a different sound source, and because the horn before and after the position is not in the same plane (for the listener), but there are differences before and after, we can imagine that the sound issued by such two units, to the ear is different, the light will destroy the human ear's positioning of the sound source, If it is serious, it will naturally produce mutual interference of high and low sound waves, and the sound quality is difficult to improve. This is also the purpose of the invention of coaxial technology.

At present, the world's three major patented coaxial speaker manufacturers all lead one side with different coaxial technology.

The British TANNOY uses a rear-treble dual magnetic circuit coaxial technology (the high-frequency driver is mounted on the rear plate of the woofer and coupled to a small horn embedded in the woofer basin). This is one of the earliest structures, and many popular speakers use this structure.

The UK KEF uses a pre-tweeter dual magnetic coaxial technology (the high frequency driver is located in front of the bass bowl, while the high frequency horn is located in the center of the low frequency horn).。

China's SOVOX created the original high and low unit shared magnetic circuit (that is, single magnetic circuit) coaxial technology.

Second, what is the difference between the sound of coaxial speakers and ordinary speakers?

Since the treble and bass units of the traditional loudspeaker are arranged on the plane of the box, as a device for restoring sound, the treble and bass of the same sound may be restored at different points, so that the distance between the treble and bass to the human ear will be different, resulting in phase deviation which affects the correct restoration of the sound image.

As we mentioned above, the treble and bass of the coaxial speaker are located in a concentric circle, so the propagation of sound is also propagated along the same axis, and the generated sound wave is also uniformly diffused outward in a circle. The separation of the treble and the bass of the ordinary speaker, due to the deviation of the position and distance of the transmission to the person, the different sounds will be disturbed by themselves, so there is serious phase distortion.

In the theater environment, because the seat height of each row is inconsistent, the left and right are inconsistent, so when the position of the speaker is certain, the time for the high and low voices to reach the ear will be incorrect. The coaxial speaker has better synchronization, and the golden area of its listening is more extensive.

The speaker system in the cinema is a surround sound system, and its large amount of surround sound highlights the sense of space and positioning, in this regard, the coaxial speaker is more accurate in reducing, effectively restoring the sound of the movie with a variety of movement rules, while the ordinary speaker is difficult to be clear and accurate.

Third, what is good about coaxial speakers?

Modern cinema, most of the use of 5.1/7.1 or multi-channel immersive surround sound system, so the positioning of sound image put forward higher requirements. Coaxial speakers as the ideal point sound source compared with other ordinary 2, 3 division speakers have the advantage of high fidelity, improve the sound quality at the same time can also synchronize with the picture, provide accurate positioning and smooth movement of sound and image, better and respected, is more and more widely used.

Perhaps some people will say that the current widespread use of 2, 3 frequency speakers are not necessarily sound bad! Indeed, coaxial unit speakers are put forward after people have higher requirements for sound quality, so we are more in the field of HI-FI applications. In the case of the continuous development of cinema sound technology, people's requirements for movie-watching experience are also improved, and the advantages of coaxial speakers are apparent. The main points are as follows:
1. A more natural sound
2. More accurate phase
3. A clearer sound
4. More controlled scattering
5. More effective coverage
6. Lower distortion rate
7. A more stable system
8. Higher heat dissipation efficiency

Of course, coaxial unit technology is still in continuous development, mainly due to material and process limitations, and the manufacturing of high-power units has bottlenecks. The main application in the theater is a small and medium power surround sound box, and the main speaker behind the screen has not adopted coaxial technology. I believe that with the improvement of technology, process, materials, etc., these problems will be solved in the future.