What Is a Stereo Amplifier?

Stereo refers to sound with a three-dimensional effect. The sound produced by nature is stereo, but if we play back these stereo sounds after recording, amplifying, etc., all the sound is released from a speaker, this kind of playback sound (compared with the original sound source) is not stereo Already. At this time, because various sounds are emitted from the same speaker, the original sense of space (especially the sense of spatial distribution of the sound group) also disappears. This replay is claimed to be mono. If the entire system from recording to playback can restore the original sense of space to a certain extent (it is impossible to completely recover), then this kind of playback sound with a certain degree of spatial distribution characteristics such as azimuth layering is called audio technology Stereo.

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English name: Stereo

Stereo refers to sound with a three-dimensional effect.

It is a geometric concept that refers to

Compared with mono, stereo has the following advantages:

• Have the sense of orientation and distribution of each sound source;

• Improved clarity and intelligibility of information;

• Improve the presence, layering and transparency of the show.

origin

Stereo recording technology was born in 1931. The inventor was British electrical engineer Alan Blumlein (1903-1942).

A brief history of sound reproduction

People have learned to do it with simple speakers early on

Introduction

Dolby Digital or DTS

To consumers, they don't seem to care much about whether a DVD video disc uses Dolby Digital or a DTS sound system. These things often need to be taken care of by the disc publisher. mostly

Surround sound playback

If you want to achieve surround sound playback on your PC, your computer needs to have the following conditions (usually a newly purchased PC will meet most of them):

• A DVD drive;

• An ordinary sound card with surround sound output (preferably with S / PDIF output to connect an external decoder) or a dedicated multi-channel sound card with 6 outputs;

• One powered 5.1 speaker or one 6-channel

  Way forward

  How will sound reproduction technology develop in the future? It is almost certain that the capacity of the media used to save sound data will definitely increase, and the Blu-ray DVD and HD-DVD already available have reached 27GB and 15GB respectively. What new technologies will emerge with such high-capacity optical discs? Will there be more channels and speakers or will we use sound processing techniques that are closer to the human auditory psychology? Or will there be a speaker array or an interface for direct control through the nerves?

  Maybe all these new technologies will come out, but none of these seem to be the key to the problem. Because in the actual ordinary home environment, it seems that the conditions for fully utilizing the existing technology can never be reached. Maybe the next generation of sound technology should be able to analyze the situation of the listening environment in real time, and then use echo and resonance to achieve the ideal sound field effect as much as possible. Such a system should also be able to sense the position of the listener and optimize the sound balance accordingly.

  To date, the film industry has been an unremitting driving force for new audio technologies. The film industry itself has also experienced ups and downs in the past few decades. If the film industry itself is at a low point, the development of audio technology will also be relatively stagnant.

  LFE channel in 5.1

  Generally speaking, LFE (low-frequency effects) channels are specifically used for low-frequency sound segments in music recording and playback. In fact, this channel is designed for some special low-frequency sounds in movies, such as earthquakes or explosions. In a cinema system, the LFE channel drives one or more subwoofers to create these special sound effects. The other five-channel speakers are able to reproduce general bass, such as the bass in human voice or background music.

  For the consideration of speaker volume and cost, some omissions will be made in the design of the home theater playback system. It will use a small midrange tweeter for 5 channels, and these 5 channels will share a separate woofer. In fact, the LFE channel is rarely used during music recording, and the general-purpose woofer of the home theater system can not only handle the LFE channel in the movie, but also the bass portion from the other 5 channels at the same time.

  Regarding how to deal with the bass part of a surround sound system, a proprietary term has even come up called "bass management".

  Stereo can be regarded as 4 different sound sources mixed together, 1 sound source is called human voice, 2, 3, 4 sound source is called beat sound.

  1 sound source is the same part of the two channels, 2 sound source is the opposite part of the two channels, 3 sound source is the part with the left channel and no right channel, and 4 sound source is the part with no left channel and right channel Some parts.

  The result of vocal cancellation is undoubtedly: new left channel = original left channel-original right channel, new right channel = original right channel-original left channel, part of the 1 sound source will disappear.

  The result of single channel mixing is: the original left channel + the original right channel becomes a channel, and the 2 sound source part will disappear.

  So the vocals can be eliminated, but the beat cannot be eliminated with the most basic stereo mix.