If you listen to the interview on NPR New Beck Album, 'Morning Phase': All Songs Considered Interview : All Songs Considered : NPR there's an interesting exchange around the 8:46 mark (you have to listen, it's not in the edited transcript):
Shortly after listening to an excerpt from "Wave"
Beck: It's funny after listening to it, the vocal got so loud after mixing and mastering. The vocal was always tucked in this ... huge orchestra.
Boilen: You actually like God.
Beck: Yeah, it's supposed to be tucked in there. But I don't know... You don't want to get in the way of the orchestra.
He sounded surprised/disappointed in how it sounded when played back to him. Sounds like the mastering wasn't something he was closely involved in.
Give it a listen.