It turned out that only one of the speakers had sound and the other had no sound. Later, the audio jacks of the two speakers were changed. Both speakers can produce sound, but one speaker plays normally, while the other has weaker sound. It plays normally while being connected to CD playback machine.
One speaker is normal but the other is weak. It may be caused by poor connection between the speaker cable and the audio interface, or improper waveform settings in Windows. First of all, you can check whether the speaker connection plug is in poor contact with the computer audio jack, or whether it cannot be fully inserted due to interface failure. If there is a problem with the interface, it should be repaired in time. In addition, open the "Master Volume" dialog box in the system to check whether the volume control is normal, such as whether the "Balance" slider of "Master Volume", "Wave" and other options is adjusted to the center; if not, drag them to the center, and the sound from the speakers should be normal.