A method for calibrating gain in a multi-path subsystem having a first processing path, a second processing path, and a mixed signal return path, may include low-pass filtering an input signal and a mixed signal return path signal generated from the input signal at subsonic frequencies to generate a filtered input signal and a filtered mixed signal return path signal and tracking and correcting for a gain difference between the first processing path and the second processing path based on the filtered input signal and the filtered mixed signal return path signal.