A classic tuned vibration absorber (TVA) is a device that, when attached to a structure, will greatly reduce the motion of the attachment at a specific excitation frequency. When a fixed frequency input is present, a TVA can be manufactured for the specific frequency input. When the input frequency changes during the course of operation, then an active adaptive TVA can be used where sensors, signal conditioning, and power are provided so that the tuned frequency can be varied over some range. A self-tuning vibration absorber (STVA) is a device that uses energy from the vibrating structure to produce some physical motion that changes the tuned frequency of the device. Through proper design, the tuned frequency will change in the appropriate direction and then stop changing when the tuned frequency matches the input frequency. This paper addresses the physics of one realization of a STVA and shows both analytical and experimental results.