Joe,
Have a look at Hauptwerk Installation and User Guide available here pages 171+
Now, know that the instrument "out of the box" is usually voiced correctly, ranks balanced correctly. Of course, your audio system, room, your hearing (aren't we all getting older every day!) and personal taste can affect the end result and you may want to tweak the amplitude and brightness.
Should you tweak too much and after a while find that you don't like the sound, no worry, you can always reset everything. So give it a try and experiment a bit
Most of my voicing is done on ranks from the pedal division and long (16') manual divisions. Usually the lower octave and a half, because of the room and standing waves, need adjustments, some notes being way too loud while you can hardly hear others notes. Brightness can also be used... with moderation
Let you ears guide you...
Good luck
François