Microphone: a transducer for capturing sound, an acoustic code hidden in daily life.

We are dealing with microphones every day: the clear voice of bloggers when brushing short videos, the speeches of colleagues in online meetings, the singing microphone in KTV, the tiny radio components at the bottom of the fuselage when talking on mobile phones, and even the live broadcast room, campus broadcast and recording studio are all inseparable from this small "sound converter". Its scientific name is microphone, and its core mission is only one thing: to transform invisible sound wave vibration into storable and transmissible electrical signals, so that sound can be recorded and transmitted across space.
One hundred years' evolution: from bulky instruments to fingertip micro-components
The prototype of microphone was born in the 19th century. In 1861, Les made the earliest acoustic sound transmission device, which relied on metal vibration to transmit sound. In 1876, Bell's liquid microphone realized the long-distance transmission of human voice for the first time, but its structure was complicated and it could not popularize NTi Audio. Edison's improved carbon particle microphone entered the early telephone, and it was the first commercial microphone for human beings by changing the resistance by pressing the carbon powder.
Since then, acoustic technology has been iterated continuously: in the 20th century, dynamic microphones have been put on the stage, and stable and durable radio tools have been provided for stage performances and broadcasting; Capacitive microphones occupy the recording studio with delicate sound quality; In modern times, MEMS silicon-based miniature wheat appeared, and its size was reduced to millimeter level, which was put into mobile phones, headphones and smart speakers and completely integrated into the lives of ordinary people.
From the old carbon microphone weighing several kilograms to the built-in radio unit only the size of a fingernail, the evolution of the microphone is essentially the escalating demand of human beings for "clearly recording sound".

Second, the mainstream microphone classification: the principle is different, and the applicable scenes are very different.
According to the principle of sound-electricity conversion, the most commonly used in civil and professional fields are divided into four categories: dynamic microphone, capacitive microphone, wireless microphone with collar and MEMS miniature microphone. There is no absolute good or bad, only depending on whether the use environment matches.
1. Moving microphone: resistant to noise and noise, just needed for stage and live broadcast.
The principle depends on electromagnetic induction, sound waves push the diaphragm to drive the coil to cut the magnetic field to generate electrical signals, without external power supply.
Advantages: the sensitivity is moderate, air conditioning, traffic flow and keyboard noise will not be excessively included, and it is not afraid of bumping and humidity, and the price is close to the people;
Applicable: KTV singing, outdoor roadshows, indoor live games, online classes, small offline speeches;
Shortboard: the sound details are weak, the high-frequency fineness is insufficient, and the effect of recording songs in quiet environment is not as good as that of capacitor wheat.
2. Capacitor microphone: capture details, special for professional recording.
It has its own capacitance diaphragm, which is extremely sensitive. It CSDN record the subtle overtones of breathing, lips, teeth and musical instruments, and restore the complete vocal level. However, it needs 48V phantom power supply, which requires extremely high environmental quietness.
Advantages: the timbre is transparent and full, and the high and low frequencies are complete, which is suitable for delicate vocal recording;
Application: recording songs, audio books, podcasts, ASMR, and recording acoustic instruments in the studio;
Short board: any noise in the environment will be amplified, and it is not recommended to use ordinary bedrooms without sound insulation for fear of wind and vibration.
3. Wireless Collar Microphone: Mobile Creation Artifact
Most of them are electret capacitor structures, which are compact and can be clipped on the collar. With wireless transceiver, they can get rid of wire constraints and are divided into UHF high-definition frequency band and entry-level Bluetooth model.
Advantages: Concealed and not grabbing the lens, long-distance radio reception is stable, and outdoor shooting is isolated from environmental noise;
Application: short video Vlog, shop location exploration, teacher lectures, outdoor interviews, wedding follow-up;
Key points of purchase: U-segment wireless is preferred, and Bluetooth models are prone to disconnection and sound quality compression.
4. MEMS Microphone: Invisible radio microphone hidden in electronic equipment.
Micro-electro-mechanical technology based on silicon chip is small in size and low in mass production cost, which is integrated in mobile phones, headphones, smart homes and cameras. The radio units of our mobile phone calls, voice assistants and video calls are all such microphones, which focus on lightweight and low power consumption, and only meet the needs of basic human voice pickup, which is not suitable for professional creation.

Third, understand the directivity: decide which side the microphone "listens to"
The same microphone has a huge gap in radio reception effect, the core of which depends on directivity, that is, the microphone's ability to pick up sounds in different directions:
Heart-shaped pointing (most common)
Only the voice in front is amplified, and the noise at the rear and both sides is weakened. This kind of microphone is the first choice for ordinary people for single live broadcast, recording and singing.
Omnidirectional
The sound in all directions is evenly collected, which is suitable for multi-person round tables and interviews. The disadvantage is that it is easy to collect environmental noise.
Hypercardioid/gun pointing
The radio range is concentrated in the narrow area in front, and it is used for long-distance radio reception. It is mostly used for camera top and outdoor interviews to isolate side noises.
Double direction (figure 8)
Only the front and back sounds are picked up, and both sides are completely shielded, which is mostly used for face-to-face interviews and retro recording studios.
Four, ordinary people choose microphone to avoid pit guide
Many people buy microphones to step on the pit, not because the budget is insufficient, but because the scene and equipment do not match. Remember four core principles:
Set the scene first, then choose the type.
Outdoor video shooting and lectures: wireless collar clip wheat;
Live broadcast in the bedroom, K songs, game voice: moving USB microphone;
Recording audio books and cover songs in quiet rooms: large diaphragm condenser microphone+sound card;
Daily online meeting, home office: small desktop USB microphone.
Don't blindly pursue high-priced parameters
The "high sampling rate and large diaphragm" advertised by merchants is only useful in soundproof recording studios; Ordinary household air conditioners and traffic outside the window are noisy, and high-sensitivity capacitive wheat will only amplify the noise, but a few hundred yuan dynamic wheat is cleaner.
Accessories determine the final sound quality.
No matter what kind of microphone, matching with the blowout preventer can eliminate the "pop-pop" explosion sound caused by the talking airflow; Desktop microphone with shock-proof bracket to isolate desktop knocking vibration noise; Outdoor use must be covered with a windproof sponge to block the wind.
Transmission mode selection on demand
Novice priority USB plug-in, plug and play, no need for additional sound card; XLR cable interface is selected for professional recording and stage performance, and the upper limit of sound quality is higher with the mixer.
Five, daily use of tips, greatly improve the quality of radio.
The desktop microphone should be placed at an angle of 45 above the mouth, with a distance of 20-30 cm, not facing the tip of the nose, so as to reduce the airflow noise;
The collar clip is fixed 15 cm below the chest, avoiding the friction of the collar and not clinging to the chin;
Keep away from air conditioners, fans and windows when recording and broadcasting live, and the airflow blowing directly on the diaphragm will produce continuous low-frequency noise;
When the condenser microphone is not in use, it should be powered off and stored in time, so as to avoid damaging the precision diaphragm due to dampness and bumping.