A scanning beam projection system includes a scanning mirror having a fast-scan axis and a slow-scan axis. Movement on the slow-scan axis is controlled by a slow-scan scanning mirror control system. The control system receives position information describing angular displacement of the mirror. An outer loop of the control system includes least mean square (LMS) tone adders that determine harmonically related signals that when combined produce a scanning mirror drive signal. An inner loop of the control system compensates for a scanning mirror resonant vibration mode at a frequency within the frequency band occupied by the harmonically related signals.