Condenser microphones use the change of capacitance to convert sound signals into electrical signals. This kind of microphone is the most common, such as the built-in microphone of a common recorder. Because it is cheap, compact, and the effect is not bad. Sometimes called a microphone.
Condenser microphones have two metal plates, one of which is coated with an electret film (mostly polyperfluoroethylene propylene) and grounded, the other plate is connected to the gate of the field effect transistor, the gate and the source A diode is connected between the poles. When the electret diaphragm itself is charged, the surface charge is Q, and the capacitance between the plates is C, then a ground voltage U=Q/C is generated on the pole. When vibrating or being rubbed by airflow, the distance between the two plates is changed due to vibration, that is, the capacitance C changes while the electric quantity Q does not change, which will cause the voltage change. The magnitude of the voltage change reflects the strength of the external sound pressure. The frequency of this voltage change reflects the frequency of external sounds, which is the working principle of electret microphones.
Condenser microphone advantages
Can convert sound directly into electrical energy signal
Condenser microphones use the principle of capacitor charging and discharging between conductors. Ultra-thin metal or gold-plated plastic film is used as a vibrating film to induce sound pressure. The static voltage between the conductors is changed directly into electrical energy signals, which are practically coupled by electronic circuits. The output impedance and sensitivity are designed.
Can show the characteristics of original sound reproduction
The audio experts take the pursuit of "reproduction of the original sound" as the highest level of audio! From the analysis of the basic design principles of microphones, it is not difficult to find that condenser microphones not only rely on sophisticated manufacturing technology, but also combine complex electronic circuits to directly convert sound into electrical energy signals. They have inherently superior characteristics, so they become a pursuit. The best choice for those who "reproduce the original sound".
Has an extremely wide frequency response
The diaphragm is the main component of the microphone that senses sound and converts it into electrical energy signals. The material and mechanism design of the diaphragm are the characteristics that determine the sound quality of the microphone. Since the diaphragm of a condenser microphone can be made of extremely thin materials, and the induced sound pressure is directly converted into an audio signal, the frequency response of the bass can be extended to ultra-low frequencies below 10Hz, and the treble can easily reach tens of KHz Ultrasound, showing very broad frequency response characteristics!
With ultra-high sensitivity
Because there is no voice coil load on the diaphragm, an extremely thin and light design can be adopted, so not only the frequency response is extremely superior, but also has excellent sensitivity, can sense extremely weak sound waves, and output the clearest, finest and accurate original sound!
Fast transient response characteristics
In addition to the characteristics of the diaphragm that determine the frequency response and sensitivity of the microphone, the ability to respond to sound waves, the so-called "transient response" characteristics, is one of the most important factors affecting the sound of the microphone. The speed of the microphone's transient response characteristics is determined by the weight of the entire diaphragm. The lighter the diaphragm, the faster the response speed. The extremely thin diaphragm of the condenser capsule has extremely fast transient response characteristics, which can show clear, bright and powerful sound and accurate audio and video. In particular, the middle and bass have no sound staining and "box sound" at all, and the treble is delicate and crisp, which is the most significant feature of the capacitive sound. It can be clearly seen from the following figure that the transient response characteristics of the condenser capsule are much better than those of the moving coil.
Features ultra-low touch noise
When using a handheld microphone, the touch noise generated by contact with the palm of the hand makes the original sound mixed with additional noise, which has a huge impact on the sound quality, especially for wireless microphones with pre-amplifier circuits, so the touch noise becomes a judge of the quality of the microphone. Important project. From the perspective of physical phenomena, the goose feathers fall to the floor like the copper plate. The goose feathers can hardly hear the falling sound, while the copper plate is very loud, indicating that lighter materials have less impact than heavier ones. In the same way, the diaphragm of a condenser microphone is relatively light and inherently has the excellent characteristics of "ultra-low touch noise".
Has the characteristics of drop resistance and impact resistance
It is inevitable that the microphone will malfunction or abnormal due to accidental drop and collision. Since the condenser capsule is composed of lighter plastic parts and a strong light metal shell, the impact force of falling to the ground is small, and the failure rate of damage is low.
Small size and light weight
Condenser microphones have the characteristics of small size, light weight, high sensitivity and superior frequency response due to their ultra-thin diaphragms, so they can be designed as ultra-small microphones (commonly known as bees and ants) for a wide range of applications.
Most suitable for mounting on wireless microphones
Condenser microphones have the above-mentioned excellent characteristics and have become the favorite of sound engineering experts and singers. Wireless microphones have become a trend in the world today to sing on stage or karaoke at home. Wireless microphones can provide capacitive sound. It has all the advantages of condenser microphones, and has become the best microphone for professional audio experts in the digital audio era.
Principles and advantages of condenser microphones
The structure is complicated, the cost is expensive, the sound film is fragile, and it is afraid of damp.