Fixing a vocal tracked at the wrong sampling rate
We have an instrumental song recorded and mixed at 48k. The song was sent to another engineer to record the vocals. When the files came back and were imported into the existing session, the vocals were slightly flat and slowed down.
You can see the original mix, and beneath it a rough mix sent back from the engineer. The two files should start and end at the same points. All files were consolidated to the beginning of the session so there was no confusion as to where they start.
I’ve seen situations like this when working with an external clock. Your clock is set to the correct sample rate but Pro-Tools isn’t slaved to the clock, so it’s recording in whatever format it was set to last. The engineer mentioned afterwards that the track sounded a little slow and weird, as he would have been recording to 48k files that were imported into a 44.1k session.
If somebody ever sends you files and something doesn’t “sound right” to you, ask them! It’s better to ask a silly question than to make a mistake!
So what do we do now? Turns out, everybody liked how the song sounded slowed down! Thank goodness, because the other option would be to speed up the vocal, which would cause more noticeable artifacts. Best not to get the “why does my vocal sound like Mickey Mouse?” email.
So all we have to do now is reverse engineer the tracking session. Start by creating a new session at the sample rate the vocal was recorded. In this instance, 44.1k. Go to File > Import > Audio and select the vocal files. Add them to the session, and when prompted create new tracks starting at the beginning of the session.
Next, go to File > Import > Audio and select your original audio files*. Click “Add”, then “Done”. You will be prompted that the files will play back at the wrong speed. Click “Yes”.
Now the vocals and the original files are in the same session and will play back at the same speed! If you want to try and pitch the track back up, try adjusting the elastic audio settings or varispeeding the track as far as you can before the vocal starts to sound weird. Or, like our case, just roll with the track slowed down! It’s a completely different feel that you wouldn’t have found by any other means!
Now, what you have is a single Pro-Tools session that is referencing audio files at two different sample rates. This is fine as long as you stay in the Pro-Tools format. For instance, even if all the audio files were consolidated to the beginning of the session, if you were to take the raw audio and import it into a different format such as Logic or Ableton they would play back at different speeds again. Get around this by highlighting all the audio, consolidating, and exporting the new audio together as one file type. You can also create a new folder to contain all the fixed audio to upload.
Ready to mix!
*In our instance we had to bring the vocal into a full multi-track session. Instead of importing the audio, I went to File > Import > Session Data. Select all your track sources, and set the destinations to “New Track”. Be sure to deselect “Apply SRC” under “Sample Rate Conversion Options”. Under “Audio Media Options” select “Link to source media (where possible)”. Main Playlist Options: “Import-Replace existing playlists” and Track Data to Import: All.