Abstract: The present invention provides a system for processing digital audio signals according to modifications selected by an equipment end-user. A signal acquisition function (200) acquires a digital input signal (202). A user interface function (214) is operatively associated with a user interface (216), and is designed to receive the digital input digital signal and to generate a user-selected fundamental frequency. A comparator function (206) receives the digital input digital audio signal, and the user-selected fundamental frequency. The comparator function outputs a portion of the digital input signal, at the user-selected fundamental frequency, to a harmonics generation function (218). The harmonics generation function receives the portion of the digital input signal at the user-selected fundamental frequency and generates a number of signal harmonics for that portion of the digital input signal based on a defined harmonics profile.