What are stereo, surround sound, and Dolby sound effects?

                    What are stereo, surround sound, and Dolby sound effects?

01 Stereo

Due to the lack of positioning of the sound in mono, the emergence of stereo technology has completely changed this situation. The sound was split into two separate channels during the recording, resulting in great sound localization.

The stereo effect is actually to use modern electroacoustic technology to adjust the volume and phase of each frequency component of each group of speakers in the left and right channels without changing the position of the left and right channel speakers, so that each group of speakers is in different positions on the front. A psychological "sound image" occurs.

Stereo technology is particularly useful in music appreciation. Listeners can clearly distinguish the direction from which various musical instruments come from, making music more imaginative and closer to on-the-spot feelings. Stereo technology is widely used in a large number of sound cards and has become an audio standard with far-reaching influence. Stereo is still the technical standard that many products follow today.

3D stereo

The difference from ordinary stereo is that it separates the subwoofer subwoofer with a frequency lower than 200Hz in the left and right channels through a low-pass filter, and sends it to a single-channel central amplifier and speaker output. Because the bass above 200Hz basically has no directionality. Therefore, the angle and position of the speaker can be moved at will without affecting the listening sound.

▲3D stereo system

03 surround sound

Compared with stereo sound, surround sound needs to add two speakers placed at the back, so that each group of speakers will not only have a psychological "sound image" in different positions on the front, but also in different positions behind, forming an all-round spatial three-dimensional sense of the sound. .

▲Surround stereo system

The surround sound effect is actually the result of delaying the sound for a certain period of time and then mixing it with the undelayed original sound to enhance the thickness and charm of the sound. The longer the delay time, the larger the echo space will be, which is what is meant by the so-called "the lingering sound surrounds the beam and lasts for three days".

Surround sound is characterized by a sense of direction, that is, the listener can feel the direction of the sound source; there is also a sense of surround, that is, the listener has the feeling of being surrounded by the sound source; there is also a sense of expansion, that is, the sound source spreads around and is reflected by objects a feeling of. When listening to a work in surround sound, we find ourselves surrounded by the music, as if we were in the same space as the recording. We are no longer spectators, if not participants, at least an inside observer.

Listeners can be surrounded by sound, or through production means, observe a piece of music in a 360° panorama. Surround sound will have a very profound effect on music. In surround sound recording, the positioning of sound and the shaping of environmental characteristics will be achieved using different methods than stereo sound. At the same time, the distance information will also present new characteristics.

04 Dolby sound effects

The full name of Dolby Sound is Dolby Pro Logic (Dolby Pro Logic), which is a surround sound system developed by Dolby Corporation of the United States.

It synthesizes the four-channel stereo into two channels through a specific encoding method during recording, that is, the original left channel (L), right channel (R), center channel (C), surround channel ( S) The 4 signals are synthesized into LT and RT composite binaural signals after encoding, and the encoded binaural composite signals LT and RT are restored to the encoded left, right, center and surround through the decoder during playback Four independent signals that do not interfere with each other are respectively input to the left speaker, right speaker, center speaker and surround speaker after being amplified.

Dolby sound settings through software can bring a better audio-visual experience. Of course, if the audio source can be connected to 5.1 speakers, then the audio-visual enjoyment will be extraordinary. It gives people an immersive feeling and is widely used in home theaters.

To put it simply, Dolby Audio is an excellent audio processor software designed to provide better audio effects. However, Dolby Audio requires the support of speakers in addition to the Toby software. Left speakers, right speakers, center speakers Speakers and surround speakers, so the real Dolby sound effect needs to be combined with four speakers to make a perfect combination.