How many buttons does the stereo usually have? What does it do?

Volume key, treble key, adjust the volume of treble component. Bass key to adjust the volume of bass component. The balance key adjusts whether the volume of the left and right channels is consistent. Turn on the key power supply; General speakers only have these buttons, or even fewer.

Audio equipment probably includes power amplifier, peripheral equipment (including voltage limiter, effector, equalizer, exciter, etc. ), speakers (speakers, speakers), mixers, audio sources (such as microphones, musical instruments, VCD, DVD) display devices, and so on.

Among them, speakers are sound output devices, sound boxes, subwoofers and so on. A speaker includes three kinds of speakers, high, low and medium, three but not necessarily three.

Extended data:

Main features of digital audio:

1, high signal-to-noise ratio: the recording form of digital audio is binary code, 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.

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: the sound quality of digital audio equipment will not deteriorate after repeated reproduction and playback. In the traditional analog cassette tape recording, the recorded noise will increase every time the tape is re-recorded, and the signal-to-noise ratio will decrease by about 3 dB every time it is re-recorded. Sub-band is not as good as master band, grandson band is not as good as sub-band, and the sound quality will gradually deteriorate.