Music loud, MIC loud .. but not on the MIXDOWN

While recording a voicetrack the microphone is very loud on my mixer. Even compared to the music.
But when I create a mixdown the mic is quite a lot softer than the music.
I understand I can increase the volume. Is this a trial and error procedure?
Or is there a default setting that would be sufficient…???

update: I’ve increased the amplification of the VT +5dB. All seems fine now.