In the question of what dB should vocals be, you should understand that the average decibels will be the “golden mean”. Thus, it is best to record vocal renditions with an average of -18 dB, assuming you are using the standard definition 24-bit.
However, louder parts such as screams or breakdowns should be -10dB. This works the other way around – the loudest and quietest recordings should be at least -24 dB. There are many rules in this business that aim to maintain the song’s balance so that vocals and all components sound with a minimum amount of distortion.
Should vocals be louder than the beat?
Unfortunately, there is no definite answer to this question. Vocal levels are highly dependent on the genre and the actual style in which you record the song. Nevertheless, maintaining balance plays an incredibly important role since no listener likes listening to a song where he practically does not hear the accompaniment but only too loud vocals.
The vocals, first of all, should involve the listener in the music, and the beat and accompaniment just keep it going. The vocals, in any case, should not be too quiet because in the mix, it can simply get lost against the background of the beat, which in principle will reduce its beauty and quality to zero. Thus, harmonious sound is the key to success!