Please tell me what stereo sound is all about

Stereo

When we listen to sound, we can tell which direction the sound is coming from, and thus roughly determine the location of the sound source. The reason why we can distinguish the direction of sound is because we have two ears. For example, if there is a sound source in front of us on the right, then, because the right ear is closer to the sound source, the sound will be transmitted to the right ear first, and then to the left ear, and the sound heard by the right ear is better than the sound heard by the left ear. The sound is slightly stronger. If the sound frequency emitted by the sound source is very high, part of the sound transmitted to the left ear will be reflected back by the head, so it is not easy for the left ear to hear the sound. This slight difference in the perception of sound by the two ears is transmitted to the brain nerves, allowing us to judge that the sound comes from the right front. This is commonly known as the "binaural effect."

If the spatial positions of different sound sources can be reflected during recording, people will feel as if they are immersed in the recording and can directly hear the pronunciation of all aspects of the sound source. The three-dimensional sound reproduced by this sound playback system is called stereophonic sound.

Use two microphones not too far apart on the stage, connect them to two amplifiers respectively, and then connect the changing current amplified by the amplifier to two speakers in another room that correspond to the positions of the microphones. middle. In this way, when an actor walks from left to right on the stage, walking and singing, the audience in another room will feel as if the actor is walking and singing from left to right in front of them. If you use two recorders to record the audio currents sent from two microphones at the same time; when playing back, put the two speakers that play back at the same time at positions corresponding to the microphones, and the sound you hear will be very good. Three-dimensional sense, this is two-channel stereo recording. Most of today's stereo magnetic recorders have two channels. Its recording head and playback head are both made of two sets of upper and lower coils. The core stack thickness of the head is more than half narrower than that of a common tape recorder. The magnetic tracks on the tape are also smaller than those of ordinary tape recorders. The recorded tracks are more than half as narrow. In this way, there are four tracks on a tape. During recording, after the sound is converted into audio current by the two microphones arranged on the left and right, it is amplified by two sets of amplifiers in the recorder and sent to the two sets of coils of the recording head. When the tape passes through the recording head, the two sets of amplifiers The recording of the vocal channel is recorded onto both tracks of the tape at the same time. During playback, when the tape passes through the playback head, the two sets of coils of the playback head respectively induce the changing currents of the two magnetic tracks, which are amplified by two sets of amplifiers respectively, and then used by the two speakers arranged in front of the left and right of the listener. The sounds of the two channels are reproduced separately, giving the listener a three-dimensional sense.