1U rack-mount digital messaging unit for scheduled audio playback. Audio files are stored on a removable SD card and may be transferred by inserting into a PC or directly recorded on the DM-8. Schedules are also stored on the SD media as a separate file, which can be edited with a PC and stored for backup. Separate SD cards may be saved with different audio messages and schedules and swapped for different routines. A mic/line input can be used for recording or for live announcements which can override SD playback. A BGM line input is provided for background music playback with its own level control and is muted when messages are playing or during paging. Up to 99 schedules can be programmed to play a particular audio file from the SD card, set by 24 hour time and day(s) of the week. The DM-8 can be added to any sound system to provide automated playback of timed announcements, music or audio alerts.