How to deal with audio noise in seminar videos
Is the "sound" of the video okay?
Video is already an indispensable marketing tool for business. You can see many expert know-how videos and seminars on YouTube. Although it is easy to shoot with a smartphone, unfortunately there is a lot of audio noise and there are many videos with poor sound quality . Here, we will introduce the basic knowledge about noise countermeasures to be taken at "home recording" and "lecture hall".
✅ Table of contents
We are engaged in "music / voice" remodeling service. After working as a music creator and a salaryman, started an independent service. Every day, while receiving orders for work from various clients who are worried about sound, I am also involved in sound adjustment of movie works, mix mastering of music works, and stage video editing.
If you do not record only the sound individually, near the performer
If you do not record only the audio individually, near the performer
When professionals shoot seminars and lectures, the built-in video camera microphone is rarely used for the main audio . In the case of a large venue, it is standard to branch the line audio connected to the speakers in the venue from a mixer and record it on the audio track of the video camera, or record it directly on another linear PCM recorder dedicated to sound . Seminar videos recorded with thick and clear sound quality like TV programs are recorded in that way.
If the branch sound source cannot be picked up due to the restrictions of the audio system at the venue, the next option is to set another microphone on a desktop near the performer, or use a wireless pin microphone to skip the sound to the recording destination.
Anyway, it means that the clear sound is recorded at the position closest to the mouth of the speaker who is the main character . If you have to shoot sound with a video camera or one iPhone, do not set it behind the audience even if you make a mistake.
If you set it behind the audience seats, you will mainly pick up the noise and rustling sounds of the audience seats instead of the voice of the performer. Not only is it noisy and jarring, but in the worst case it is not uncommon for the performer to not understand what he is saying. Recently, as a measure against corona, when a performer gives a lecture while wearing a mask, it tends to be even more difficult to hear .
If you want to record everything with one camera, ignore the audience seats and secure the closest angle to the performer. When using a whiteboard or screen, Atsuhiko Nakata's YouTube University angle is the basis. (Of course, since it is professional content, wireless pin microphones are used)
Sound monitor that is indispensable when recording
Professional photographers always wear headphones. Do you make a trial recording when recording the seminar video? At that time, are you recording without checking the audio being recorded?
For videos and photos, be sure to check the screen on which you see them, compose and record them, right? In particular, most amateur video recordings are recorded without checking the audio. Just by changing the position of the microphone, you can improve the hearing of your voice and suppress the sound of the room.
Every smartphone or camcorder has a headphone connection jack. Be sure to monitor the "sound" when recording with your earphones. You can improve the quality just by checking the recorded sound properly.
Let's take a test shot of the person who records with SELPHY and check what kind of sound is being recorded. At that time, the speakers built into the video camera and smartphone cannot be used for detailed distinction .
Points when connecting an external microphone
If you use an external microphone, the quality will improve at once. Voice functions vary depending on the model and manufacturer, but adjusting the voice level is very important. While monitoring the sound of ①, it is essential to set the level meter so that it does not swing completely. (The limiter is automatically applied to the video of the iPhone camera)
If the audio function has a low-cut filter, don't hesitate to add it. There is a lot of noise in the bass part, such as footsteps and projector fans, and it is difficult for unnecessary noise to enter by adding it, so it is often the case that the sound is refreshing, so it is recommended to turn it on for the time being because you do not know the effect. ..
Recording method performed by a video company at the lecture hall
When a professional video production company records a seminar or lecture, three cameras (manned x 2, fixed x 1) are the standard settings. Voice recording is always performed from the microphone spoken by the performer via the mixer * line recording.
* The mixer has the role of branching audio data to the camera and recorder in order to sound other microphones and BGM to the venue speakers.
If there is an audience seat, the photographer will shoot in the last row of the audience seat, so the sound of the microphone connected to the camera will pick up all the noise and voice of the audience seat. Therefore, only the audio data of the microphone used by the performer is recorded directly separately from the camera. (Depending on the settings, you can also record on the camera body)
The microphone for the venue and the line sound spoken by the performer are mixed and mixed to make the sound easy to hear. The same method is basically used for TV press conferences. If you want to add value to the content of the seminar even in seminar videos that do not require complicated editing, these audio edits are essential.
Noise removal app used by professionals
Dedicated noise processing applications are also used in the field where higher quality is required. The most famous and excellent noise removal is iZotope's RX.
It is possible to reduce reverberation components and repair sound cracks, not just noise processing.
The audio grades of videos shot with a single smartphone and professional videos differ due to the accumulation of these various factors. There are various options depending on the production cost and how much editing time you spend.
For video editing and sound quality improvement of seminars , please contact HybridSoundReform.com . HybridSoundReform.com is a sound quality improvement service that handles sound adjustment and noise removal for movies released in theaters. We provide high-level voice restoration such as seminars where the sound is cracked due to setting mistakes, improvement of troubles, reduction of engine sounds and children's voices that have been mixed in unexpectedly. We also handle about 50 commercial video edits a year. Please feel free to contact us.