Mixing 4 channels to 2 [SOLVED]

I have v2.1.2, using Windows 7, zip
Am still new to Audacity and I need a kickstart for this: I have recorded 4 channel sound, 2 as stereo front, 2 as stereo back. They are already synched from the recording. I want to mix them and export as 2 channel stereo. What basic steps should I follow?

It depends what the recording is. If it’s speech with background music then simply discarding the rear channels will probably give the best results.

If it’s a film soundtrack (or similar) with important elements of the sound in the rear channels (such as a sound approaching from behind) then you will need to “mix” the rear left with the front left to create a new left channel, and mic the rear right with the front right to create a new right channel. To do that, set both “left” channel tracks to “Left channel” in the track dropdown menu (see: http://manual.audacityteam.org/o/man/audio_track_dropdown_menu.html) and both right channel tracks to “Right channel” in similar fashion. Then open the “Mixer board” view from the View menu (see: http://manual.audacityteam.org/o/man/view_menu.html#mixer) and adjust the track levels until it sounds right. When you’re happy, use “Mix and Render” from the Tracks menu to mix the tracks down into a single stereo track. You can then “normalize” the track using the “Amplify” effect to adjust the maximum peak level to a suitable level. For a WAV file, -1 dB is good. For MP3 I prefer to have the level a little lower, say -2 dB.
Then export (see: http://manual.audacityteam.org/o/man/file_export_dialog.html)

Steve, Thank you so much for your reply. This is just what I needed to get started mixing.

Steve, I don’t understand how to "set both “left” channel tracks to “Left channel” in the track dropdown menu " and do the same for the right. I have loaded the tracks and opened the track dropdown menu, but I don’t see how to do it.

Do you have four Audacity tracks or two?

If you have two Audacity tracks where each says Stereo, and the left and right are correct in each, I don’t understand why you need to use the Audio Track Dropdown Menu. Just Tracks > Mix and Render. If the result is too loud, Edit > Undo Mix and Render and turn the gain -…+ slider down on each track before mixing again.

To use the Audio Track Dropdown Menu click in the name of each track (see the red oval in the image below)

If you already have four tracks, click in the name of each track and click “Left” for the two tracks that you want to be Left and “Right” for the two tracks you want to be Right.


:blush: Sorry, I misread the original post and assumed that you has a single 4 channel file (which Audacity would import as 4 mono tracks).

As Gale wrote, the job is simpler than I originally described.

The first part of my answer still holds. If the recording is speech with background music, the best result will probably be to just use the front channels (because the rear channels will probably just contain echo/reverberation of the music).

Otherwise, just use the “Mixerboard” or the track Gain controls (both do exactly the same) to balance the amount of front / rear sound until it sounds “right”. Then mix down to stereo (select both tracks and “Tracks menu > Mix and Render”), Normalize and export.

Gale and Steve, Thanks so much, this worked out great!