Double-click on the desktop icon to your preferred digital audio workstation, such as Cubase or Pro Tools. Depending on your preference settings, this action will open either a blank session or the last saved work-in-progress. If the relevant session did not open automatically, click "File", then "Open," and select it from the drop-down menu.
Open the mixer interface. Typically, a digital audio workstation has two view options, one for arranging and editing, and one for mixing. The method for opening a different interface varies according to which program you use. For example, in Ableton Live, click the small circular tab in the top-right corner of the screen to switch between the two. In Logic, click the "Mixer" tab at the bottom of the screen.
Click on all instrumental tracks to highlight them. This assigns subsequent commands to just the instrumentals, rather than the mix as a whole.
Right-click on any of the highlighted instrumental tracks. Click "Send To," and select the first available bus. This command will apply to all highlighted audio. Nonavailable busses, such as those being used for effects, will be grayed-out. In audio, a bus is an audio channel that lets you group multiple tracks in one place. Rather than adjusting each instrumental track individually, send them to a bus. This is called submixing, which allows you to control the volume of the entire instrumental with a single fader.
Send all vocal tracks to a different bus using the same method. This creates two channels, one with instrumental and one with vocals.
Click on the bus channel used for grouping the instrumentals to highlight it.
Open the "File" menu, and select "Export." When prompted, select your preferred file type. Typical options include MP3 and Wave Audio files. The former is smaller and quicker to export, while the latter is larger and slower to export but has a better sound quality.
Export the vocals as an individual file.
Open a new project from the "File" menu.
Click "File" again and select "Import." Select the instrumental file first. Then select the vocal files. This makes both files open as individual tracks for the new session in the "Arrangement" interface. The previously saved volume levels will be in imported with the audio files.
Open the "Mixer" interface.
Drag the "Gain" fader for the instrumental track, and pull it down. This lowers the collective volume of the instrumental audio in relation to the vocals, making the vocals louder by comparison.
Click "Save As," and name the track "Song Title Submixes."