Headphone knowledge science -- moving iron
Generally speaking, the volume of moving coil headphones is relatively large, because under the limitation of the current technical level, the moving coil unit shown in the figure above must have a certain size. There is a formula in physics: P=Fv. P is power, F is force, and v is velocity.
When doing low-frequency vibration, the speed of the coil and the diaphragm is very small, so when the power P is constant, the driving force F has to become larger, and the size of the driving force is proportional to the cross-sectional area of the magnetic field. Therefore, if the structure of the moving coil unit is too small, the force generated by the current passing through is not enough to make the coil drive the diaphragm to vibrate at low frequencies, and the bass performance of the earphone will be greatly reduced. However, there are still many moving coil earphones with small size but good sound quality, which are only relative to moving iron earphones in general.
Moving iron headphones are far superior to moving coil headphones in terms of music dynamics, instant detail performance, and sound density. Relatively speaking, the price of moving iron earphones is not so close to the people. An entry-level moving iron earphone may cost several hundred yuan, and the price of a fever-level moving iron earphone may be tens of thousands, which cannot be competed with moving coil earphones among mass consumers. This is one of the reasons why many people have never heard of moving iron headphones. After all, moving iron units were generally only used in more sophisticated instruments such as hearing aids. In addition, the moving iron unit can be made smaller due to structural reasons, so there are multi-unit moving iron earphones. These headphones do a particularly good job of presenting the overall frequencies of the sound.
Of course, moving iron headphones are not without their shortcomings. Compared with starter coil headphones, its disadvantage lies in the sound field. Moreover, although its frequency presentation ability is relatively strong, the presentation of low frequencies is not as natural as that of dynamic headphones.
