The process of mixing a multi-track recording down to a lower number of tracks. Traditionally this has always been two tracks, but nowadays with the advent of DVD and other multi-channel technologies it is common for mixes to be mixed to as many as seven tracks (or even more in some circumstances). This is traditionally the last, and arguably most critical phase of music production that is done in a recording studio. After this step the master tape (data) is sent to a mastering facility that specializes in the process of preparing them for public consumption. Sometimes even the mixdown is done at a separate facility with a special mixing engineer.