Differences between audio tracks and Audio Channels

Audio Track

In the past, when a singer recorded a video in the recording studio
That is, let the artist and the band record together
The singer sang while the band accompanied
Then the recorder recorded these sounds together.
Most readers think that recording is like this.
And it was recorded in the past.
However, this recording is inconvenient.
That is, if the singer fails to sing, the recorder wants the singer to start singing again.
Then the band will start playing the accompaniment again.
It's okay if a singer fails to sing a song once or twice.
If a singer fails to sing three, four, or more times
Then the band is about to repeat for four, five, or more times.
This is not uncommon.
In this way, the band will be dissatisfied.
Will there be another round-robin award?
Later, we adopted a new technology to avoid such inconvenience.
That is, let the band play separately and use the recording device to record it, just on a single audio track.
Then let the singer bring his earphones and listen to the band's accompaniment recording,
And recorded on another track parallel to the accompaniment track
If the singer is wrong, you need to sing again. You just need to record the accompaniment.
This technology is a dual-track technology that combines multiple sounds to achieve a variety of sound effects.
In fact, we sing karaoke using sound track technology.
In fact, we are talking about the dual-track technology and the multi-track technology. We can record three or four or more sounds into separate audio tracks and play them together.

Channels

The number of sound channels supported by the sound card is one of the important indicators to measure the sound card grade. From Single Channel to the latest surround sound, the following details:

1. Single Channel

Single channel is a relatively primitive sound replication form, and early sound cards were widely used. When two speakers play back the single channel information, we can clearly feel that the sound is transmitted from the middle of the two speakers to our ears. This kind of recording method without a sense of location is naturally lagging behind in the current perspective, but it was already a very advanced technology when the sound card was just getting started.

2. Stereo

The lack of single-channel location for sound has completely changed this situation. The sound is allocated to two independent channels during the recording process, thus achieving sound positioning. This technology is particularly useful in music appreciation. The audience can clearly distinguish the directions of various musical instruments, so that the music is more imaginative and closer to the on-site feeling. Stereo technology is widely used in a large number of sound cards since the sound blster pro and has become a far-reaching audio standard. Today, stereo is still the technical standard followed by many products.

3. Quasi-stereo

The basic concept of a quasi-stereo sound card is to use a single channel when recording a sound, while a sound is sometimes a stereo or a single channel. Sound cards using this technology have also been popular on the market for some time, but they have disappeared.

4. Surrounded by four sound channels

People's desires are endless. Although stereo sound satisfies people's requirements for the sense of left and right sound positions, with the further development of technology, we gradually find that dual channels are increasingly unable to meet our needs. The emergence of PCI sound cards has brought about many new technologies, among which the most advanced 3D sound effects have been developed. The purpose of 3D sound effects is to bring people a virtual sound environment, and use special HRTF technology to create a realistic sound field, so as to achieve better game audio effects and sound field positioning. To achieve good results, it is far from enough to rely only on two speakers. Therefore, the stereo technology is too slow in the face of three-dimensional sound effects, however, this problem is well solved by the four-channel surround audio technology.

The four channels define four pronunciation points: front left, front right, back left, and back right. The audience is surrounded in the middle. We also recommend that you add a bass speaker to enhance the playback of low-frequency signals (that is why the 4.1-channel speaker system is widely used today ). In terms of the overall effect, the four-way sound system can bring sound from multiple different directions to the audience, and provide users with a new experience. Nowadays, the four sound channels technology has been widely integrated into the design of various medium and high-grade sound cards, and become the mainstream trend of future development.

5.5.1 audio channel

5.1 channels have been widely used in a variety of traditional cinema and home theater, some of the more well-known sound recording compression formats, such as Dolby AC-3 (Dolby Digital) and DTs are all based on the 5.1 sound system technology, among which ". 1 "sound channel is a specially designed ultra-bass sound channel, which can generate a frequency range of 20 ~ Hz subwoofer. In fact, the 5.1 sound system comes from the 4.1 surround. The difference is that it adds a central unit. This center unit is responsible for transmitting sound signals less than 80Hz. It is helpful for enhancing the voice when you enjoy the video and concentrated the conversation in the middle of the sound field to increase the overall effect. I believe that every real experience of the Dolby AC-3 sound effects of friends will be 5.1 channels of the service.

From: http://blog.chinaunix.net/u2/70445/showart_2025208.html