What is stereo?

Watching widescreen movies will definitely be more real than watching ordinary movies, and there will be an immersive feeling.

Widescreen movies have a wider screen than ordinary movies, and the characters and scenes are correspondingly larger, which is of course a factor that we feel realistic. In fact, its stereo also played a great role.

What is stereo? Why use it?

The space we live in is of course three-dimensional, and the voices we hear in our daily life come from all directions. People's ears have an instinct that they can tell where the sound comes from as soon as they hear it-that is, they can judge the location of the sound source (the person or thing that makes the sound). If you see a person talking on your left or right, but the voice you hear seems to be coming from right in front, will you feel strange? Ordinary movies are like this.

When watching ordinary movies, we can not only distinguish the left and right positions of people and things, but also distinguish the distance between people and hands. But its sound comes from a speaker in a fixed place (even if some cinemas use two or more speakers, the sound is the same, and the effect is similar to that of one speaker). You see, the sounds made by people and things distributed in different places on the screen are all from the same speaker. Is this different from the real situation? The audience will feel it as long as they pay a little attention. The screen of widescreen movies is much wider than that of ordinary movies, and the distance between characters increases accordingly. If you still use the same sound as an ordinary movie, then the sound source on the screen is far from the sound source (speaker), which is even more unreal.

In order to make the sound of widescreen movies sound stereoscopic, it is necessary to make the sound entering the left and right ears have obvious time difference and loudness difference. To achieve these two requirements, it is necessary to change the pronunciation method of general movies.

If we put several microphones in front of the person or thing making sound (at a certain distance from each other), the sound they receive is different in time and loudness. If the sound received by each microphone is recorded separately, then the same number of speakers are placed in the corresponding position of the cinema, and these recordings are played back separately, the sound heard by the audience will have a three-dimensional effect. Experience has proved that it is enough to record three tones with the left, middle and right microphones. Three speakers were also used in the screening, which were placed in the left, middle and right positions respectively, which can produce quite good stereo effect. This truth is not complicated, because when the person or thing making sound is close to the left, the microphone on the left receives the strongest sound, followed by the middle one and the weakest one on the right; When playing, the speaker on the left is the strongest, the speaker in the middle is weak, and the speaker on the right is the weakest. Although the three speakers sound at the same time, the audience sounds as if the sound is coming from the left. If the person or thing making the sound is in the middle (or near the right), the situation is similar. When playing back, I feel that the sound is coming from the middle (or the right), which produces a stereo effect.

Recently, TV is also trying to adopt stereo; In the near future, stereo may also be widely used in TV.