Basic knowledge of acoustics - talk about stereo

                        Basic knowledge of acoustics - talk about stereo

stereo concept

Stereo is a system composed of two or more sound transmission devices, transmission channels and loudspeakers (speakers, earphones). After appropriate system layout adjustments, the spatial distribution of the scene can be obtained. We call it stereo.

Everyone has two ears. In the monophonic PA system, we can hear the spatial distribution and orientation of the sound position. This is what we call the binaural effect. The binaural effect is the effect that people rely on the volume difference, time difference and timbre difference between the two ears to judge the direction of the sound. When the sound intensity is different, you can feel the distance between the sound source and the listener.

For example, when we are rebroadcasting a band performance, if we use a recording device to die (or use several pickups and mix them together) to amplify through one channel and then play it out by one or a group of speakers, this is mono system

Compared with monophonic and binaural, it is not only the difference in spatial distribution and positioning, but also restores the original spatial distribution of sound. When the mono tracks are recorded and amplified separately, the sound quality of stereo will be greatly improved compared to mono, and the sense of presence will be enhanced. But there are still some differences between two-channel stereo and multi-channel stereo, four-channel, and surround sound. For example, the 5.1 stereo channel in the picture below, the surround sound of the theater, etc.

So is the more channels the better? No, in fact, as long as the speakers with the same height of the musical instrument and the speaker stereo system with the same height as the human ear can get a very good listening experience in the original actual performance venue, it is like we used to often use the center speaker but now it is very difficult. Rarely seen, because the stereo effect of the two left and right channels is already very good. As for general performance venues, two sets of line arrays are generally used to solve the problem.

Then, in addition to the three subjective perceptions of the loudness, timbre, and pitch (frequency) of the sound, the human ears also have the ability to locate the sound. This ability is due to the time difference between the sound reaching the two ears and the sound pressure level. different capabilities.