[IT Encyclopedia] What is the channel

Sound Channel refers to the independent audio signals collected or played back in different spatial positions when the sound is recorded or played, so the number of sound channels is the number of sound sources during sound recording or the corresponding number of speakers during playback. The number of channels supported by the sound card is one of the important indicators for measuring the sound card grade.

Mono

Mono is a more primitive form of sound reproduction. Early sound cards were more commonly used. When the monaural information is played back through two speakers, we can clearly feel that the sound is transmitted from our two speakers to our ears. This kind of lack of sense of position recording method is naturally backward with the current eyes, but when the sound card has just started, it is already a very advanced technology.

Stereo (Stereo)

Monophonic lacks position of the sound, and stereo technology completely changes this situation. The sound is assigned to two independent channels during the recording process, so that a good sound positioning effect is achieved. This technique is particularly useful in music appreciation. The audience can clearly distinguish the directions of various musical instruments, thus making the music more imaginative and closer to the on-the-spot experience. Stereo technology is widely used in a large number of sound cards since the Sound Blaster Pro, and has become a far-reaching audio standard. Today, stereo is still the technical standard that many products follow.

Quasi-stereo (Prospective stereo)

The basic concept of a quasi-stereo sound card is to use monaural sound while recording sound, which is sometimes stereo sound and sometimes mono sound. Sound cards using this technology have also been on the market for some time but have now disappeared.

The desire for four-channel surrounds people is endless, although stereo meets the requirements of people's sense of position and sense of the left and right channels, but with the further development of technology, we gradually find that the two-channel has become more and more unable to meet our needs. . Since the advent of the PCI sound card has brought many new technologies, the development of the fastest three-dimensional sound effects. The main purpose of the three-dimensional sound effect is to bring people a virtual sound environment and create a real sound field through special HRTF technology, so as to obtain better game auditory effects and sound field positioning. To achieve good results, relying on two speakers alone is not enough, so the stereo technology is in the face of three-dimensional sound effects, but four-channel surround audio technology is a good solution to this problem.

The four-channel surround defines four pronunciation points: front left, front right, back left, back right, and the audience is surrounded by this. It is also recommended to add a subwoofer to enhance playback of low-frequency signals (this is why the 4.1-channel speaker system is widely popular today). In terms of the overall effect, the four-channel system can bring the sound surround from multiple different directions to the audience, and can achieve the auditory experience in various environments, giving the user a totally new experience. Today, the four-channel technology has been widely integrated into the design of various types of high-end sound cards and has become the mainstream trend of future development.

5.1-channel 5.1-channel has been widely used in various traditional theaters and home theaters. Some well-known sound recording and compression formats, such as Dolby Digital (D-3) and DTS, are based on the 5.1 sound system. The ". 1" channel is a specially designed subwoofer. This channel can produce super bass with a frequency range of 20 ~ 120Hz. In fact, 5.1 sound system comes from 4.1 surround, with the difference that it adds a central unit. This central unit is responsible for transmitting sound signals below 80Hz. It is beneficial to enhance the vocal sound while enjoying the film, and focuses the dialogue on the middle of the entire sound field to increase the overall effect. I believe that every friend who has really experienced Dolby AC-3 sound will be impressed by 5.1 channels.

Do not assume that 5.1 is already the pinnacle of surround sound, and a more powerful 7.1 system has emerged. Based on 5.1, it added two left and right middle pronunciation points in order to achieve a more perfect realm. Due to the relatively high cost, it is not widely used.

The role of the 7.1-channel 7.1-channel system is simply to establish a relatively balanced sound field around the listener around the listener. Unlike the 5.1-channel sound field, it adds a post-middle sound field to the original sound field. Road, at the same time, it is also different from the normal 6.1-channel sound field, because the 7.1-channel has a two-way rear center, and the biggest role of the dual-way rear center is to prevent the listener from hearing it because they are not seated in the emperor's place. The deviation of the sound field. Because people have two or more ears, if you only have a center trumpet at the back, the sound field will be biased. This deviation will cause sometimes you think that the sound is closer to the left because your left ear receives the sound first. Sometimes the sound will be on the right side, and the sound field will not have three-dimensional, almost flat sound, it sounds wrong. The reason is: When the front of your ears is not directly facing the sounding point, you need two speakers to correct the phase difference, which is why listening to music to use at least two speakers (stereo). Therefore, the sound field and phase that can be created with two surround back speakers is a more advanced configuration in the home theater field.