Generally speaking, the volume of background music should be lower than the main audio elements such as dialogue and narration, so as not to interfere with the hearing of the main voice. But it should not be too low, otherwise the effect of background music will be lost.
Specifically, the volume of background music can be controlled between-15dB and -30dB. The level in this range can make the background music create a suitable atmosphere and emotional effect without affecting the main voice.
It should be noted that different editing software and audio processing software may have different grade standards, which need to be adjusted according to the specific situation. At the same time, it is necessary to make appropriate adjustments according to the actual situation of the video to ensure that the final sound effect meets the requirements.