A device includes a disk drive assembly configured to store information using a platter comprising a magnetic material surface and a magnetic head disposed above the magnetic material surface. The magnetic head is configured to move across tracks formed on the platter to write information to the magnetic material surface and read information from the magnetic material surface. The device also includes a controller operatively coupled with the disk drive assembly. The controller is configured to dynamically adjust the height of the magnetic head above the magnetic material surface at each of the tracks by determining a harmonic ratio for a particular track and comparing the harmonic ratio to a reference harmonic ratio for the track. For example, the controller calculates a difference between the harmonic ratio and the reference harmonic ratio.