Spend thousands of dollars to buy a microphone, and the sound quality is still broken. 90% bloggers are planted in these six invisible radio pits.

Have you found this strange thing:

The mobile phone comes with a noisy microphone. It's hard to get started with hundreds of wireless collars and large diaphragm capacitors. It's still ugly to shoot and broadcast live.

Breathing is booming, clothes are rubbing and screaming, and when they get close to the speaker, the current is buzzing during the whole charging process, and passers-by brush it until they hear the noise and row it away directly, and the flow is stuck for hundreds.

Many businesses only sell equipment and never talk about practical radio logic. I have been doing audio for 5 years. Today, I have uncovered the invisible defects of microphones that are rarely disclosed in the whole network, and avoiding them can directly improve the video completion rate.

First, the fatal pit: blindly turn up AI to reduce noise, and the human voice is directly distorted into a robot.

Almost all wireless collars have multi-stage noise reduction, and 90% of bloggers have the strongest noise reduction all the year round, which seems to isolate noise, but in fact it destroys the texture of human voice.

1. The underlying logic of strong noise reduction: DSP algorithm cuts across the board low-frequency sound waves, eliminates traffic and wind noise, and smoothes out all the warm voices and tone details in the chest. Oral broadcast with goods, emotional explanation, strong noise reduction, stiff speech and no appeal, the audience listened to fatigue and quickly quit.

2, scene standard gear (copy directly)

Indoor home and study oral broadcast: weak noise reduction, only filtering the continuous bottom noise of air conditioners and refrigerators, and the human voice is complete and full.

Street shop and market location: Mid-range noise reduction, balance noise and human voice thickness.

Strong wind, subway and downtown are extremely noisy: turn on the power for a short time to reduce noise, and immediately transfer to the mid-range after filming.

3, hiding skills: don't rely on noise reduction for wind noise, give priority to windproof sweaters, physical noise reduction without loss of sound quality, algorithm noise reduction is only an aid.

Second, the invisible pit: the near-talk effect will not be controlled, and the voice is turbid like a mouthful of water.

The general acoustic problem of moving coil and heart-shaped condenser microphone, the closer you talk, the more the low frequency explodes, the bass is mushy and the microphone is sprayed seriously. Many people mistakenly think that the microphone is of poor quality.

1. Wrong operation: within 5cm of sticking the mouth to the wheat head, the low frequency of the chest cavity is over-amplified, and the breathing airflow is roaring. No matter how balanced the later editing is, it can't be saved.

2. Universal Golden Distance

Hand-held live dynamic wheat: 12-15cm, with thick windproof cotton.

Collar clip wireless microphone: fix the clavicle, more than 20 cm away from the mouth, and prevent the collar from rubbing and overlapping low-frequency noise.

Desktop recording condenser: 15-20cm, with blowout prevention net.

3, clever use of details: recording a deep narration, uncle's voice line can be shortened to 8cm, moderately increase the sense of thickness, and at the same time open the 80Hz low cut to offset the excess turbid low frequency.

Third, multi-person shooting in the hardest hit area: the double wheat is offset with the video position, and the sound is thin and empty.

When two microphones are turned on at the same time in two-person interview and two-position shooting, the voice is weak and the sense of transparency disappears at high frequency, and many people can't find the root of the problem-sound wave phase conflict.

1. Principle: There is a distance difference between the sound and the two microphones, and the sound waveform is positively and negatively cancelled, and the middle and high frequencies are directly lost, so that the hearing is dry and there is no hierarchy. If the distance between two microphones is less than 30cm, the cancellation problem will be infinitely magnified.

2, 3 kinds of high frequency scene solutions

Two people each wear a collar and clip wheat: the horizontal spacing is ≥40cm. Only one main track is reserved for editing, and the other is reserved. Do not directly superimpose the tracks.

Top gun microphone+hand-held main microphone: placed back and forth in a staggered manner, with a distance of more than 50cm, and the mixer is turned on for phase inversion.

Multi-camera synchronous recording: The built-in audio of other cameras is all silent, and only one main radio microphone is used for the whole process.

3, self-check tips: mute a wheat alone when playing human voice, the sound instantly becomes clear and full, that is, phase cancellation, immediately adjust the position.

Fourth, the culprit of current limiting in the live broadcast room: the directional blind spot is placed incorrectly, and the noise is poured into it crazily.

The dead angle of different microphones is completely different. If the air conditioner, host, speaker and traffic outside the window are aimed at the blind area, all the noises will be included.

1. Heart-shaped wheat (mainstream live handheld wheat, desktop wheat)

The front radio is clear, and the back 180 is the attenuation blind area. Never aim at the back of the wheat, such as the computer mainframe, the external air conditioner and the speaker. The 90 noise on the side is only attenuated by half, and the window facing the street avoids the side.

2, super heart-shaped gun wheat (for outdoor short video)

The blind area of radio reception is in the oblique rear, which makes the noise reduction stronger, but the sound source in the oblique rear is easy to be included. When shooting, the noise of speakers and passers-by avoids the oblique rear.

3, all-directional collar clip wheat

360 no dead angle radio, full coverage of environmental noise, suitable for home quiet environment, street shooting must be matched with mid-range noise reduction+windproof cover.

V. Buzz of charging current: 90% bloggers step on the wire transmission pit.

The live broadcast is charging while receiving the radio, and the current noise continues to hum. It is useless to change your microphone. The problem is not the microphone, but the wire transmission mode.

1. Unbalanced 3.5mm ordinary audio cable: Only two signal cables can easily pick up 5G electromagnetic interference from chargers, lights and routers, and the noise is obvious when the wires exceed 1.5 meters.

2. Balanced TRS large three-core/XLR line: three-core positive and negative cancel interference, and there is no noise in the 10-meter long line, which is necessary for professional live broadcast.

3. Quick solutions

There is a current sound in the mobile phone radio: replace the balanced adapter cable and temporarily disconnect the audio cable when charging.

The wireless microphone is far away from power adapters, light strips and routers to reduce electromagnetic interference.

Sixth, the conference/live broadcast array wheat misunderstanding: thinking that more wheat is equal to long-distance clarity.

Online classes, conference rooms, ring-shaped multi-wheat array merchants promote long-distance radio, and actually use radio to roll over frequently.

1. Limitation of beam pickup: the array forms a narrow radio beam, and the volume is directly halved by 30 degrees from left to right, so that people sitting side by side will have a very small voice.

2. Correct layout: the personnel are seated longitudinally in front and back, and aligned with the center of the array; The microphone and the sound box are placed vertically at 90 degrees to prevent echo howling.

3. Distance to the red line: The array effectively receives 1-3 meters. When it exceeds 3 meters, the signal-to-noise ratio plummets, and the voice is weak. Long-distance shooting does not depend on the array wheat.

A set of practical summary, collection and comparison debugging:

Single indoor oral seeding: heart-shaped wheat 12–15cm, weak noise reduction, 80Hz low cutting, balanced wire, noise source aimed at wheat back;

Outdoor short video collar clip wheat: clavicle wear, mid-range noise reduction, wind-proof sweater, away from charging power supply;

Two-person shooting: the distance between two wheat is over 40cm, and no double audio tracks are superimposed;

Meeting room array microphone: sit vertically, and the microphone is placed vertically on the speaker.