What does it mean “optimized for your headphones”?

The first layer is optimizing sound for your particular headphones by applying a calibration profile. All headphones color sound, therefore, we start by calibrating them to the studio (neutral) reference level. It’s the same technology that’s behind Sonarworks precision audio software Reference 4 used by Grammy-Award-winning music creators and in 45'000 professional recording studios around the world. Calibration creates a consistent starting point for you to accurately start personalizing your sound based on your sound preferences and unique hearing.