The sound of booming drums would often be the first identification of Chris Carter's Millennium television series, accompanying the bright white fading Polaroid effect when introducing a new scene. In fact the accompanying booklet to the 2008 release of the limited edition Millennium soundtrack by Mark Snow specifically mentions the drums:
One of the recurring elements of Millennium's sound design was the use of heavy, low pounding drum hits, used to introduce Snow's title theme or bring the viewer back into the show after a commercial break. The drum material was the work of music editor Jeff Charbonneau, whose collection of percussive musical sounds appealed to the show's producers. "Jeff is a really fantastic music editor and he's done a lot of movies," Snow said. "He had a collection of single percussive booms and hits that were really great. There's never a pattern in these percussive hits, but we would sprinkle them into the music in places."
Presented in this download are versions of both the double and single hit Millennium drums. These are not the exact same drums as in the series; you can read more about their origin in this news article from way back in 2001! You can download them in standard Windows .wav format and also in three different bitrate versions of MP3, depending upon your your application. For example, you may wish to use the MP3 format as an SMS Text Message alert, or an app notification.