Main characteristics of digital audio
1, high signal-to-noise ratio
The recording form of digital audio is binary coding, and only "0" or "1" is needed for playback. Therefore, the noise of the recording medium has little influence on the signal-to-noise ratio of the reproduced signal. The recording form of analog audio is a continuous sound signal, which will be affected by tape noise when recording and playing, and will be superimposed on the sound signal to make the sound quality worse. Although noise reduction measures have been taken in analog audio, they cannot be eliminated fundamentally.
2. Low distortion.
In the process of analog audio recording and playback, the nonlinearity of the magnetic head will introduce distortion, so measures such as AC magnetic bias recording must be taken, but the distortion still exists. In digital audio, the magnetic head only works in magnetic saturation or non-magnetic state, that is, 1 or 0, and there is no linear requirement for the magnetic head.
3, good repeatability
Digital audio equipment has been copied and played back many times, and the sound quality will not deteriorate. In the traditional analog cassette tape recording, every time the tape is re-recorded, the recorded noise will increase, which will reduce the signal-to-noise ratio by about 3dB. The sub-band is not as good as the master band, and the solar band is not as good as the sub-band, and the sound quality will gradually deteriorate.
4, the sloshing rate is small.
Because of the function of time-base correction circuit, the instability of rotating system and driving system in digital audio playback system will not cause chattering, so there is no need to require precise mechanical system as in analog recording.
5, strong adaptability
Digital audio records binary code, and all kinds of processing can be carried out as numerical operation, without changing hardware, only using software to operate, which is convenient for microcomputer control, so it has strong adaptability.
6, easy to integrate
Because of digitalization, it is convenient to adopt VLSI, the whole machine is convenient to debug, with stable performance and high reliability, which is convenient for mass production and can reduce the cost.