Due to its mature technology, low cost and relatively easy to make features, dynamic earphone has always been in the absolute mainstream position of earphone products. However, it can not be ignored that the high-frequency performance, transient response and sound field naturalness of dynamic earphone have congenital defects, and different from the speaker, because the volume of the earphone unit itself is smaller, so it is in motion In order to avoid the shortcomings of the moving coil loudspeaker itself, the structure of the moving coil loudspeaker is improved.
　　When we talk about earphone products, we still need to discuss them together with speakers, because many of the technologies of earphone products come from the technology decentralization of speaker products, and we need to further improve the production accuracy to meet the requirements of earphone products. The principle of flat-panel speakers is still not very different from that of moving coil headphones. Of course, electrostatic speakers are also a kind of flat-panel speakers, but they are not the protagonists we are going to talk about today.
　　Because the sound producing plane (diaphragm) of a common moving coil loudspeaker is not a completely horizontal plane, but a conical structure, it is difficult for the conical structure diaphragm to emit a uniformly distributed sound radiation, so it is unable to completely bring a relatively flat frequency response. This is why we look at the frequency response curve of many earphones and speakers compared with that of amplifiers For example, the curvature is much larger.
　　Therefore, in order to make the loudspeaker have a relatively flat frequency response curve and reduce the vibration of the diaphragm as much as possible, it is necessary to improve the diaphragm itself. Therefore, the acoustic performance of an absolutely flat diaphragm is better than that of a conical diaphragm. For example, it is not realistic to make the paper basin into a plane with the common paper basin loudspeaker on the speaker, because it not only has insufficient strength, but also has a narrow frequency response range, and there will be more serious segmentation vibration.
　　With the development of material technology, the choice of diaphragm materials for earphones and loudspeakers is no longer limited to paper pots and plastics. More new materials such as beryllium plating, aluminum plating, titanium plating and so on have emerged. For planar loudspeakers, there is also a glimmer of dawn. Nowadays, the common flat panel loudspeaker diaphragm material is more like a printed circuit made on the film, which not only ensures a certain degree of rigidity, but also brings smaller vibration than the moving coil headphone unit.
　　Therefore, theoretically speaking, the loudspeaker unit of flat earphone has a certain advantage in acoustic performance compared with the common dynamic earphone loudspeaker unit, due to the absence of the anti chamber effect caused by the conical loudspeaker So it can bring more flat frequency response, and the piston vibration range of the diaphragm is wider, which can effectively reduce the distortion in the bandwidth. Behind all these advantages is the unremitting pursuit of high fidelity audio playback, which is what we call hifi in the true sense.