4-Track Audio Mix: How to prep the master sequence

When working with a 4-track mix, you will need to change several settings in order for the tracks on your sequence to output via the correct channels to your master. The term “channels” is rarely brought up since the vast majority of mixes are plain ol’ stereo mix, and both the editing systems and VTR presets are setup as such, so you don’t need to do anything. Not the case with a 4-track mix. The four tracks of audio in your sequence need to be routed through the correct channels so that tracks 1/2/3/4 are actually recorded on the tape on audio tracks 1/2/3/4, respectively. Here is a checklist of the settings you will need to change in order to output a 4-track mix to a 4-track master:

Press cmd + zero to change the sequence to a 4-track sequence. Select the Audio Output tab, and change the Outputs to “4″, then select the correct designation of channels according to your mix specs, i.e. 1/2 Stereo or Dual Mono, 3/4 as Stereo or Dual Mono.

• Go to User Preferences and do the same thing.
• Go to Audio/Video Settings, select Device Control, change Audio Mapping to 4 Channels.
• On your master sequence, CTRL – click somewhere on the row of each track next to the track buttons and select Audio Outputs for each track to be sure it is routed to the correct channel. A typical 4-track mix would have full stereo mix on tracks 1/2, and stereo music and effects only on 3/4. In this case, tracks 1/2 should be routed to stereo channels 1/2, tracks 3/4 to stereo channels 3/4. However, if tracks 3/4 are dual mono, track 3 should be routed to a mono channel 3, and track 4 to a mono track 4. The channel patching does not “read” the mix file and do it for you.
• Be sure you have reference tone on all four tracks and that they are panned correctly. Playback should indicate equal levels on all tracks regardless of stereo or mono.
• Check the VTR to be sure all four audio inputs are set to the correct input protocol, i.e. Analog or Digital
• If your edit suite mixer is 4-track capable, be sure you have the correct faders up with the panning set correctly.

FCP has this annoying habit of playing back a four track mix to four tracks on a VTR, but when you output to tape, it switches to two tracks on the VTR. This happens when you haven’t changed the Audio Mapping on the Device Control settings tab in Audio/Video Settings.

You can use the multiple channel presets for regular editing too. It’s not just for output. I have seen documentary editors patch 4 tracks of dialog and effects to mono channels 1/2, and 4 tracks of music to stereo channels 3/4 so they can ride the mix during playback. In other words, you can have as many tracks as you want patched to any number of channels, so long as your output card and mixing board are setup to actually hear them.

Video Demo: FCP setup for 4-channel audio output