Working with Audio Tracks

When you add an audio file to your project, Motion creates one or more audio tracks for the file. In the Audio tab of the Project pane, you can turn audio tracks on and off, select tracks, mute and solo tracks, and control their volume and pan settings.

Figure. Audio tab showing mutliple audio tracks.

Any changes you make to an audio track, such as renaming or trimming it, do not affect the source audio file.

Turning Audio Tracks On or Off

When you add an audio file to your project, it becomes a track in the Audio tab and is turned on by default. You can turn individual audio tracks on or off in the Audio tab. Turning off an audio track silences it during playback and means the track is not part of your final mix when you export the project.

To turn an audio track on or off
Do one of the following:
  • In the Audio tab of the Project pane, click the activation checkbox on the left side of the track. Click the checkbox again to return the track to its previous state (on or off).

  • In the Timeline, with the Show/Hide Audio button turned on, click the activation checkbox (in the left column). Click the checkbox again to return the track to its previous state.

Turning an audio track off removes it from the overall audio mix.

Selecting Audio Tracks

To display an audio track in the mini-Timeline and in the Audio Editor, you first select it.

To select an audio track
  • Click anywhere in the row containing the track’s name and controls in the Audio tab. Selected tracks are highlighted.

    You can select multiple tracks by Shift-clicking. However, the Audio Editor can display only one track at a time. When multiple tracks are selected, the Audio Editor appears empty.

Playing Audio Tracks

When you click the Play button in the transport controls, you hear the audio tracks in your project play in time with your visuals. You can also play an individual audio track separately from the project Timeline.

To play audio with your project
  • Click the Play button in the transport controls.

    When you click the Play button, you hear all audio tracks in the project that are turned on and are not muted.

To play an individual audio track
  1. In the Audio tab, select the audio track.

  2. In the Audio Editor, click the Play button.

    The audio track plays, and the playhead in the Audio Editor shows the region of the track currently playing. Playback in the Audio Editor is independent of the project.

    By default, when you play audio tracks, the playback sample rate and bit depth are determined by the playback device. If you are playing audio using an external device, Motion plays the audio using the sample rate of the device.

Muting and Soloing Tracks

When you mute an audio track, it is silent during playback, but is still part of the mix when you export your project. When you solo an audio track, all other audio tracks are muted, which lets you hear the soloed track more clearly.

Figure. Audio tab showing Mute and Solo buttons.

You can mute, unmute, solo, or unsolo an audio track at any time, even during playback. When you export your project, all tracks that are turned on are included in the final mix, regardless of whether they are muted or soloed.

To mute an audio track
Do one of the following:
  • Click the Mute button.

    Click the Mute button again to unmute the track.

  • Control-click the track, then choose Mute from the shortcut menu.

To solo an audio track
Do one of the following:
  • Click the Solo button.

    Click the Solo button again to unsolo the track.

  • Control-click the track, then choose Solo from the shortcut menu.

You can also solo multiple audio tracks. When you solo more than one track, all tracks not soloed are muted (silent) during playback.

Setting Levels

Level refers to the loudness or volume of an audio track (sometimes referred to as gain). You can adjust an audio track’s level using the Level slider. The available range is from –96 (minimum level) to 6 (maximum level). The default is 0 (sometimes called unity gain). The values correspond to the decibel scale (dB).

Figure. Audio tab showing Level slider and value field.
To set an audio track’s level
  • In the Audio tab, the track’s HUD, or the Audio Track tab of the Inspector, drag the Level slider to set the level you want. In the Audio tab, the Level slider is located in the Name column under the track’s name.

    In the Audio tab and Audio Editor, you can also type a number in the value field. You can set the level in integer increments (–1, 0, 1, and so on).

Selecting Output Channels

If you’re working with multichannel audio, you can adjust which tracks are assigned to which output channels, or you can create your own multichannel file from mono tracks.

To set or change output channels for an audio track
  1. Choose 5.1 Surround from the Master Output Channel pop-up menu at the bottom of the Audio tab.

    Figure. Audio tab showing Master Output pop-up menu.
  2. Choose an output channel for the specific audio track from the Output Channel pop-up menu (in the track list of the Audio tab).

    Figure. Audio tab showing Output Channel pop-up menu.

    Note: If you do not have surround-sound hardware, the Center, LFE, Left Surround, and Right Surround output channels will be italicized. You can still select those channels and your choices will be reflected in an exported project or playback on a system that does have the right hardware.

Setting Track Panning

Pan refers to the left-right balance of a track in the stereo field. You can adjust a track’s pan position using the Pan slider. The available range is from –100 (hard left) to 100 (hard right). The default is 0 (center).

Figure. Audio tab showing Pan slider.
To set a track’s pan position
  • In the Audio tab, the track’s HUD, or the Audio Track tab of the Inspector, drag the Pan slider to the left or right to set the pan position for the track.

    In the Audio tab and Audio Editor, you can also type a value in the value field. You can set the pan position in integer increments (–1, 0, 1, and so on). The pan field shows numbers in a three-digit format (000, for example).

Locking Tracks

Locking a track prevents it from being edited. When a track is locked, you cannot mute or solo the track, change its level or pan, move or trim it, or add keyframes. You can still play the track, and turn it on or off.

To lock a track
  • In the Audio tab, click the lock icon on the right side of the track. Click the lock icon again to unlock the track.

Renaming Tracks

You can also rename a track, to give it a more useful name in the project.

To rename a track
  • In the Audio tab, double-click the track’s name in the Name column, then type a new name.

Working with the Master Track

Each project has a Master audio track. The controls for the Master track are located at the bottom of the Audio tab, below the individual audio tracks. Using the Master track’s controls, you can make changes that affect the final mixed output of all audio tracks. For example, you can lower the volume of all tracks at once, or pan all tracks to the left or right. In addition, you can turn the Master track on or off, or mute it.

Figure. Audio tab showing Master audio track controls including activation checkbox, Level and Pan sliders, Mute button, Output Channel pop-up menu, lock icon, level meters and clipping indicators.

You select the Master track by clicking its area at the bottom of the Audio tab. When selected, the Master track area appears highlighted.

Turning the Master Track On or Off

The Master track is turned on by default. When it is deselected, no sound is audible when you play the project, and no audio is included when you export your project. When it is turned on, all audio tracks that are turned on are included in your export.

To turn the Master track on or off
  • Click the checkbox at the left side of the Master track. Click the checkbox again to return the Master track to its previous state.

    When the master track is selected, a master waveform appears in the Audio Editor.

Setting Master Level

You can use the Master Level slider to set the overall volume level for the audio in your project.

To set the master level
  • Drag the Master Level slider to set the level you want.

    The Master level works in conjunction with the level setting for each individual track. For example, if you set a track’s level to 0.5 and you set the master level to 0.5, the combined level is 0.25 (one-fourth) of the original.

    Note: If you raise both an individual track’s level and the Master level so that the combined increase is greater than 2, you may cause audio distortion or “clipping.”

Viewing the Master Level

To the right of the Master track controls is a pair of stereo level meters that display the combined level of all the audible tracks.

If either of the two red dots above the level meters (called clipping indicators) light up during playback, this indicates that your master levels are too high, causing audio distortion or clipping.

Preventing Clipping

Typically, when working with digital audio, audio engineers set the overall volume level as high as possible without causing clipping. If the clipping indicators light up above the master level meters, you need to find where clipping is occurring and lower the level to eliminate the cause of the clipping.

If clipping occurs, play the project and observe where the clipping indicators light up. You may want to solo each audio track to determine if a particular track is causing the clipping. You can also play a track in the Audio Editor and watch the Audio Editor’s level meters, which show only the levels of the track playing.

Once you determine which track is causing the clipping, you can lower the track’s overall level, or use keyframes to lower the track’s level at the specific point in time where clipping occurs.

Figure. Level meters and clipping indicators in the Audio tab.

The clipping indicators are “sticky,” meaning that once they light up, they stay lit until you reset them or close the project. This is intended to help remind you to find and eliminate the cause of the clipping before you export your project. As you work to eliminate clipping, reset the clipping indicators and play the project again to make sure clipping no longer occurs.

To reset the clipping indicators
  • Click the clipping indicator that is lit.

Setting Master Pan

You can use the Pan slider in the Master track to set the left-right pan position for the audio.

To set the Master pan position
  • Drag the Pan slider to place the sound where you want it in the stereo field.

    The Master pan slider works in conjunction with the pan setting for each individual track. For example, if you pan a track to –100 (hard left) and you pan the master to 100 (hard right), the track is inaudible.

Slipping Audio Tracks

When you import an audio file, its start point is set to the location based on the setting of the Create Layers At parameter in Motion preferences. You can slip an audio track so it starts playing at a different point in time.

Figure. Mini-Timeline showing an audio clip being slipped.
To slip an audio track
  1. In the Audio tab, select the track.

    The bar for the audio file appears in the mini-Timeline.

  2. In the mini-Timeline, drag the track’s bar left or right.

    As you drag the bar, a help tag appears, showing the In and Out points for the track.

    Note: You can also show and slip the timebar for an audio track in the Timeline. To display audio in the Timeline, click the Show/Hide Audio button in the display options (located in the lower section of the Timeline layers list).

Trimming Audio Tracks

You can edit the start and end points of an audio track to cut down the length of the audio in the track, or to have it start or end at a specific point in time. This is called “trimming” the track. Motion lets you trim audio tracks, either visually or by entering numeric values for the In and Out points.

When you trim an audio track, the audible part of the track is highlighted in green in the Audio Editor. Trimming an audio track is nondestructive and does not affect the original audio file.

To trim an audio track visually
  1. In the Audio tab, select the audio file you want to trim.

    The track’s timebar appears in the Audio Editor and in the mini-Timeline.

  2. In the Audio Editor or the mini-Timeline, position the pointer over the beginning or end of the timebar, and the trim pointer appears.

    Figure. Audio Editor showing audio timebar and trim pointer.
  3. Drag the beginning or end of the timebar to the point where you want to set the In or Out point for the file.

    The progress of your trim is displayed in the Audio Editor and lets you see the time markers, so you can trim more precisely.

To trim an audio track numerically
Do one of the following:
  • In the Audio Editor, type a value in the In field where you want the track to begin, or type a value in the Out field where you want the track to end.

  • Click the arrow at the left edge of the field to decrease the value, or click the arrow at the right edge of the field to increase the value. Shift-click to move in increments of 10.

  • Position the pointer over the number in either the In or Out field, and the drag pointer appears. Drag left to increase the value, or drag right to decrease the value.

    Figure. Audio Editor showing a trimmed area highlighed in green.

Scrubbing an Audio Track

You can scrub an audio track in the Audio Editor to hear a portion of the track. Use the Audio Scrubbing button to turn scrubbing on or off. Scrubbing is turned on by default in the Audio Editor (it is off by default in the Timeline).

To scrub an audio track
  1. In the Audio tab, select the track.

  2. If scrubbing is turned off, click the Audio Scrubbing button, located at the lower-left corner of the Audio Editor, to turn on scrubbing.

    Figure. Audio Scrubbing button in the Audio Editor.
  3. Drag the playhead in the Audio Editor left or right. Keep the pointer still to loop continuously on the frames adjacent to the current frame.

    Note: By default, audio scrubbing loops continuously on the five frames adjacent to the current frame when you keep the pointer still. You can turn off looping by choosing Motion > Preferences, clicking the Project icon, then deselecting the “Loop audio while scrubbing” checkbox under Playback Control.

    You can also scrub audio in the Timeline or Keyframe by Option-dragging in the ruler at the top of the Timeline. You can scrub audio in the mini-Timeline by Option-dragging the playhead in the mini-Timeline.