Microphone and speaker knowledge
Microphones and speakers are the entrance and exit for sound entering and exiting electronic devices and recording equipment, respectively. Microphone is a member of the Ttansducer family, whose main function is to convert energy from one form to another. The function of the microphone is to convert the air fluctuation and pressure generated by the sound into a fluctuating level signal suitable for the use of electronic devices. On the contrary, the function of the speaker (speaker) is to change the fluctuating level signal back to the air fluctuation and pressure, which is the sound we hear.
To make the microphone not affect the recording quality, then it must adapt to the sound with a wide dynamic range. For example, when drumsticks strike a string drum, the volume difference between before striking and the moment of striking is very large, and the microphone must be able to cope with this surprising contrast in loudness. Even the human voice can produce a wide range of sound levels. The microphone used to record music must be able to convert the whispers and loud shouts into electrical signals with the same accuracy, and then record them into the computer through the mixer.
Microphones can be classified into two categories: dynamic microphones and condenser microphones. There is a diaphragm made of a certain fabric on the dynamic microphone, and the diaphragm can vibrate with sound waves. The diaphragm is connected to a voice coil with multiple turns of wire around the outside. The voice coil moves in the magnetic field generated by the magnet inside the microphone, cutting the lines of magnetic force and generating a current corresponding to the vibration of the diaphragm. This current represents the sound signal.
Although there are many different types of dynamic microphones (the most common of which is a ribbon microphone that uses a thin metal band instead of the diaphragm and coil), the use of "moving coil" dynamic microphones is so common that it is "moving coil". And "dynamic" has almost become synonymous. In the following sections, when we talk about dynamic microphones, we refer to dynamic microphones. The dynamic microphone is simple to use, reliable in performance, and has a very wide and stable frequency response, so it is often used in live performances and recording studios.
However, not all dynamic microphones have the same excellent performance. The quality of the microphone is affected by factors such as the level and strength of the manufacturer. The way that condenser microphones convert sound waves into electrical signals is different from that of dynamic microphones. Condenser microphones have two plates that are close to each other but do not touch each other. The pole plate is connected to a battery or other power source and is charged. One of the plates is designed to move with different sound pressures, while the other is fixed. When one pole plate moves back and forth relative to the other pole plate with the fluctuating sound pressure, a voltage consistent with the change in sound pressure is generated between the two pole plates, thereby generating electricity for input to the mixer signal.
Among the best-performing microphones currently manufactured, some are condenser microphones, but they are surprisingly expensive, and some are priced at several thousand dollars. They are not suitable for home recording studios, are they? Of course, there are some variants of condenser microphones on the market that are more practical for home studios. The electret microphone is a kind of low-cost and high-quality condenser microphone. The electret microphone does not require two polarized plates to which a polarization voltage is applied. The capacitors used in the electret microphone are already polarized when manufactured by the manufacturer and can maintain a permanent charge. The electret microphone needs an amplifier/impedance converter to replace the low-voltage power supply.
Although some condenser microphones are considered ideal microphones, they are very delicate and not suitable for all situations. Generally speaking, condenser microphones are more sensitive than dynamic microphones, especially for high-frequency signals and transients (transients, sounds that are suddenly produced and quickly disappear). Although condenser microphones respond well to transient signals, they can also overload these signals. Therefore, condenser microphones are not commonly used to pick up drums, rock guitars, and explosions.
There is also a new type of microphone called PZM (pressure zone microphone). The PZM microphone has a good reputation. It is... a condenser microphone that uses a flat surface as an external pickup. The microphone records the sound pressure built up by the sound wave on the surface of the flat panel, and the frequency response is uniform, which is very suitable for picking up a wide band of musical instruments and room ambience. In a piano ensemble or a small band ensemble, a set of PZM microphones can get a better pickup effect.
If a larger flat area is used, the low frequency response of PZM microphones can be enhanced to a certain extent, so they are often attached to walls, music stands, piano covers or other surfaces. Although PZM microphones are used in many The occasions work well, but they haven't done much in recording vocal performances.