ACD is an audio format used by an audio editing software. ACD file don’t store any actual audio data, but information about an audio project, including:

• applied audio effects,
• sample libraries used,
• equalizer settings for each audio source,
• audio file output parameters.
• ACD files are created by MAGIC ACID software application.

Changing ACD extension to, for example, MP3 will not change ACD file’s format. In order to open an ACD file in MP3 Player, such file must be converted using an appropriate tool.