Learn about how to change track timebases and the effect of changing the track timebase on MIDI clips vs. audio clips.
- [Instructor] Although tracks are assigned to default timebase according to the track type you can change the track timebase at any time. Changing a tracks timebase will affect how the track responds to tempo changes in your session. Let's take a look at how to change a tracks timebase and how that can affect the track behavior. In this session I'm working with two drums tracks, an audio track with two audio clips, and an instrument track with two midi clips. And I'll re-enable the tempo ruler for now. The tracks are currently using their default timebases as assigned in the new tracks dialogue box.
When you create an audio track the timebase defaults to samples while midi tracks and instrument tracks default to ticks. You can change a tracks timebase in the new track dialogue box, but you can also make changes later after the tracks are already in the session. So let's take a look at that. To change the timebase for a track you can use the track timebase selector in the edit window here at the head of the track.
The timebase selector will show a blue clock icon for sample based tracks and a green metronome icon for tick based tracks. So here I can click on the time based selector for the audio track and change it to tick based timing. Doing that will cause the audio clips on the track to be referenced to tick based locations on the bars beats ruler. In this case, the first clip starts at bar three and the second clip starts at bar five. So now if I change the session tempo by disabling the tempo ruler we can see that the start of the first clip remains at bar three and the start of the second clip remains at bar five.
As I adjust the tempo the clips move in absolute location to retain their staring bar and beat positions. Notice that the clips themselves do not speed up or slow down, however. So they overlap at a higher tempo and spread apart at a lower tempo. Audio clips behave like solid blocks of concrete, but on a tick based track the start of each block is anchored to it's bar beat position. Now let's re-enable the tempo ruler for a moment.
And now let's see what happens if I change this instrument track to sample based timing. And once again I'll click on the track timebase selector at the head of the track and this time I'll select samples. Doing that will cause the midi information on the track to be referenced to sample locations, which are fixed in time. If I click on the minute seconds here to make it the main timebase we can see that the first clip starts at 4.705 seconds and the second clip starts at 9.411 seconds.
Changing the session tempo at this point will have no effect on the midi clips. So if I disable the tempo ruler the midi clips retain their minutes seconds locations and remain stationary as I adjust the tempo. So that's all there is to changing track timebases. You can select the timebase for tracks as you create them in the new tracks dialogue box or you can use the timebase selector in the edit window to change an existing track's timebase. Changing an audio track from sample based to tick based will anchor the start of the audio clips to locations on the bars beats ruler causing the clips to move as the session tempo changes.
This can be especially effective when working with one-shot samples such as clips of individual notes or single drum hits. Changing a midi track from tick based to sample based will anchor the midi data to sample locations causing it to be fixed on the minute seconds ruler. This can be effective when you import a midi clip into a new session and then need to match the session tempo to the existing midi performance. As your work with Pro Tools evolves, you'll likely encounter many scenarios where changing the default track to timebase is useful.
We'll come back to this topic when we discuss elastic audio processing later in this course.
- Starting a new session
- Customizing settings
- Optimizing the performance of Pro Tools
- Importing loops and tracks
- Working with meter changes
- Recording multiple takes
- Changing the track timebase
- Editing MIDI clips
- Warping sound and tightening rhythm with Elastic Audio
- Using the Smart Tool
- Color coding tracks
- Editing on the grid
- Working with AudioSuite plug-ins
- Working with sends, plug-ins, and master faders
- Working with track subsets
- Finalizing and exporting media