Methods, apparatus, and articles of manufacture for reducing spillover in a media monitoring system are disclosed. An example method includes determining an actual frequency spectrum of the media monitored by a meter, and determining absolute values of differences between amplitudes of corresponding frequency components of the actual frequency spectrum and an expected frequency spectrum, the expected frequency spectrum stored in a database in association with a media identifier corresponding to the media. An example method also includes determining whether spillover occurred based on a summation of the absolute values satisfying a threshold, crediting the media with a media exposure if spillover did not occur.