Digital microphone, abbreviated as MIC, is a type of sound to electricity conversion device, sometimes also known as "digital microphone", "digital microphone", and "digital microphone". It is one of the widely used electroacoustic devices in sound systems. Its function is to convert voice signals into electrical signals, then send them to a mixer or amplifier, and play them out from the speaker. In other words, digital microphones are used to pick up sound in sound systems. It is a part of the entire audio system. The quality of its performance has a significant impact on the entire audio system.
Classification of digital microphones
1. According to the principle of energy conversion, it can be
divided into electrical digital microphones, capacitive digital
microphones, electromagnetic digital microphones, piezoelectric
digital microphones, and semiconductor digital microphones;
2. According to the directionality of the received sound waves,
they can be divided into non directionality and directionality.
Directional digital microphones include heart-shaped
directivity, strong directivity, and bidirectional
directivity;
3. It can be divided into stereo, close-up speakers, wireless
microphones, etc.
Dynamic digital microphones are commonly used microphones. It
mainly consists of vibrating diaphragm, voice coil, permanent
magnet, and step-up transformer. Its working principle is that
when people speak into the microphone, the vibrating film
vibrates back and forth with the sound, driving the voice coil
to cut off the magnetic field lines. According to the principle
of electromagnetic induction, an induced audio electromotive
force is generated at both ends of the coil, thereby completing
the conversion of sound and electricity. In order to increase
the output induced electromotive force and impedance of the
microphone, a step-up transformer is also required. This utility
model has a simple structure, reliable stability, convenient
use, and low inherent noise.
Early dynamic digital microphones had low sensitivity and a
narrow frequency range. With the maturity of manufacturing
technology, many professional dynamic digital microphones have
emerged in recent years, which have good characteristics and
technical indicators and are widely used in language
broadcasting and sound reinforcement systems.
During outdoor sound pickup or human voice pickup, the wind and
airflow in the human voice can impact the diaphragm of the sound
electric conversion section, causing huge noise to the
microphone and even preventing the diaphragm from moving freely.
At this point, wind protection is necessary. The wind shield
plays this role. This utility model consists of a metal cover on
the outer shell and an internal sponge. The metal shell can
resist external impact and protect the microphone; Sponge will
weaken and prevent airflow from entering.
In this way, the air movement when people speak and the air
movement of the wind will not affect the sound pickup effect.
Due to the fact that sound is not a directional movement of
airflow, but a mechanical fluctuation, it is almost unaffected
by the wind deflector. In strong winds, the interference effect
of airflow may be significant, and a windproof device can be
added to the outer shell of the microphone.
In addition, sound resistance, nylon mesh, and resonant cavity
are acoustic processing measures set up by microphones to
improve sound quality.
