Quantizing audio

Quantizing audio is a quick way to tighten up the feel of an audio track. AudioSnap provides several ways to quantize audio:

You can quantize audio to the project’s Time Ruler. This is useful for tightening up a performance in a project that already has a fixed tempo or varying tempo map. For details, see To quantize audio to the project’s Time Ruler.

You can copy the feel of one track and apply it to another track. There are four ways to accomplish this with AudioSnap:

Method 1: Extract MIDI timing from the source track, then use Groove Quantize on the target track. For details, see To extract MIDI timing from an audio clip and To Groove Quantize an audio clip.

Method 2: Add the source track to the Pool, then quantize the target track to the pool. For details, see To quantize an audio clip to another audio clip (Quantize to Pool) and Using the Pool.

Method 3: Use the Extract Timing button on the AudioSnap palette to extract the timing from selected clips, then use the Apply Groove button to apply the extracted groove to the selected clips. For details, see To extract the groove from one clip and apply it to another clip.

Method 4: You can manually match transient markers across multiple tracks by using the Smart tool. For details, see To manually match transients across different tracks.

To quantize audio to the project’s Time Ruler

1.	Select the audio clip you want to quantize.

2.	Press ALT+A to open the AudioSnap palette.

3.	Click the Quantize button in the AudioSnap palette.

The Quantize dialog box appears.

4.	Make sure the AudioSnap Beats check box is selected.

5.	Configure the Quantize options as desired, then click OK.

Sonar quantizes the selected clips.

Note: You can only quantize to one rhythmic value at a time. If you don’t want to quantize all beats in an audio clip (to ensure the Quantize command doesn’t move them to a rhythmic placement where they don’t belong), temporarily disable any transient markers you don’t want to quantize. For details, see To disable a transient marker.

To Groove Quantize an audio clip

The Groove Quantize command aligns transients with a groove that’s on the Clipboard or a pre-existing groove file. If you want to copy the timing from another audio clip to the Clipboard, see To extract MIDI timing from an audio clip.

1.	Select the audio clip you want to groove quantize.

2.	Press ALT+A to open the AudioSnap palette.

3.	On the Process menu, click Groove Quantize.

The Groove Quantize dialog box appears.

4.	In the Groove File field, select either Clipboard or the file that the groove pattern you want to use is saved in.

5.	In the Groove Pattern field, select the groove pattern that you want to use.

6.	Select the Resolution value that you want to quantize to.

7.	Make sure the AudioSnap Beats check box is selected.

8.

Click OK.

To extract the groove from one clip and apply it to another clip

1.	Select the audio clip you want to extract the groove from.

2.	Press ALT+A to open the AudioSnap palette.

3.	Click the Extract Timing button.

The clip’s groove is extracted and vertical Pool lines are displayed to indicate the extracted transients.

4.	Select the clip you want to apply the groove to.

5.	Click the Apply Groove button.

The groove is applied to the selected clip and the Pool is cleared.

To manually match transients across different tracks

1.	Select the Smart tool in the Control Bar.

2.	Assign the track’s Edit Filter control to Audio Transients.

Audio clips show transient markers and the AudioSnap palette appears.

3.	In the Control Bar’s Snap module, select the Landmark Events button .

Note 1: If events do not appear to snap to audio transients, go to Edit > Preferences > Customization - Snap to Grid (or right-click the Snap to Grid button ) and make sure the Audio Transients check box is selected under Landmarks.

Note 2: When snapping audio transients, the following rules apply: 4 If a Pool exists, audio transients snap to the Pool. 4 If a Pool does not exists, audio transients snap to transients in the selected tracks. 4 If there are no selected tracks, audio transients snap to transients in the selected clip.

4.	Select the audio tracks that you want to use as the rhythm guide.

5.	Identify the transient markers you want move, then drag the transient markers until they snap to the nearest transient markers in the selected tracks.

To quantize an audio clip to another audio clip (Quantize to Pool)

A common problem arises when two or more clips aren’t quite in sync with each other. You can fix this with AudioSnap if the sync errors aren’t huge. The AudioSnap command that is most helpful in this situation is the Quantize to Pool command. The way it works is you decide which clip has the correct rhythm, you add that clip’s transient markers to the Pool, and then you quantize the other clip’s transient markers to the Pool.

1.	Select the Smart tool in the Control Bar.

2.	Assign the track’s Edit Filter control to Audio Transients.

Audio clips show transient markers and the AudioSnap palette appears.

3.	Select the audio clip that you want to use as the rhythm guide.

4.	Disable any transient markers that you want to exclude from the Pool (see To disable a transient marker).

5.	Right-click the selected clip and select Pool > Add clip to pool on the pop-up menu.

The selected clip is added to the Pool, and its transient markers turn purple.

6.	Select the audio clip that you want to quantize.

7.	Right-click the selected clip and select Pool > Quantize to pool on the pop-up menu.

The Quantize to AudioSnap Pool dialog box appears.

8.	Configure the following settings as desired:

Max Distance From Pool. The value in this menu determines which notes are affected by the Quantize to Pool command. For example, if you choose Quarter in the menu, notes that are farther than a quarter note from a Pool line are not quantized.

Quantize Window. This slider fine tunes the value in the Max Distance From Pool menu. A window of 100 percent includes all markers that lie within the Max Distance From Pool value.

Quantize Strength. This slider controls quantize strength, which determines how closely the selected notes move to the Pool markers.

9.

Click OK.

The transients in the selected clips are quantized to the Pool.

 

See also:

To extract the groove from one clip and apply it to another clip

To quantize multi-tracked drums without stretching audio

When you fix timing errors in multi-tracked drum parts, you will frequently need to adjust all the drum parts in exactly the same way, because drum parts often contain “bleed”—the sound of other drums in the track of the drum that you are trying to record. For example, if your snare mic also picks up some of the hi-hat sound, you can’t move hi-hat clips around without also moving the snare clips in exactly the same way, because if you don’t, the sound of the hi-hat in the hi-hat track will conflict with the sound of the hi-hat in the snare track.

AudioSnap’s Add Transients to Pool command and Split Beats into Clips command allow you to slice your drum tracks at identical locations, so you can then drag or quantize whole clips without stretching any audio. This method of aligning clips does not change the phase relationships between the clips, as long as you move all the clips identically.

Let’s take a look at some multi-tracked drum parts, and see how to quantize them all in exactly the same way. The following project uses 10 mics, including room mics and overhead mics:

1.	Select the Smart tool in the Control Bar.

2.	Assign the track’s Edit Filter control to Audio Transients.

Audio clips display transient markers and the AudioSnap palette appears.

3.	If necessary, edit each drum track’s transient markers so that there are no extraneous transients (use the Threshold slider, disable some transients, move others, etc.).

4.	Disable all the transient markers in the overhead mic and room mic tracks.

Note: The room mics and overhead mics are much farther from the drums than the close mics, so the transients in their tracks occur a little later than the close mic tracks. Because you will eventually split each beat into a separate clip, you only want to use the transient markers from the close mic tracks to avoid cutting off any transients.

5.	Select all the drum tracks.

6.	Right-click any selected drum track and select Merge and Lock Markers on the pop-up menu.

7.	All transient markers on all selected tracks are copied to each drum track, so all drum tracks share identical transient markers. The clip positions are also locked.

8.	On the Edit menu, point to Clip Lock and click Lock Position.

The clip positions are no longer locked.

9.	Select a drum track that has steady beats throughout the song.

Tip: If there is not a single drum track that has steady beats throughout the song, you can create a temporary guide track by bouncing all the drum tracks to a single track (select all the tracks, use the Edit > Bounce to Tracks command, select Hardware Outputs in the Source Category field in the Bounce to Tracks dialog box, and click OK).

10.	Click the Set Project Tempo From Clip button to align measure lines with drum track and establish a tempo map.

The project’s measure boundaries line up with the transients in the drum tracks.

Note: If the measure boundaries do not line up properly with the drum tracks, you may need to edit the guide track’s tempo map. For details, see To edit a clip’s tempo map.

11.	Select all the drum tracks.

12.	Click the Split Beats into Clips button on the AudioSnap palette.

Each beat is split into a separate clip.

Now we can quantize all the clips at the same time. Let’s quantize this example to eighth notes:

13.	Select all the clips that you want to quantize.

14.	Use the Process > Quantize command to open the Quantize dialog box.

15.	In the Duration field, choose Eighth (for this example).

16.	Configure the other settings as follows:

Make sure the AudioSnap Beats check box is cleared.

Make sure the Audio Clip Start Times is selected.

Make sure the Auto XFade Audio Clips check box is selected, and the XFade and Max Gap values are set at their default values.

17.	Click OK to close the Quantize dialog box.

After some processing time, the clip start times move to the eighth note boundaries:

Some clips now overlap, and some clips have small gaps between them. Because the Auto XFade Audio Clips check box was enabled, and the XFade and Max Gap values were set at their default values, crossfades have been automatically added between clips, and any gaps that were smaller than the Max Gap value have been filled in. Let’s zoom in to take a closer look:

A. Crossfades

Now the clips line up with eighth note boundaries, no audio has been stretched, and phase relationships have been maintained.

For information about maintaining phase relationships when stretching audio, see Adjusting the timing of a multi-track performance while maintaining phase relationships.

 

See:

Quantizing

To split a clip, quantize it, and fill in the gaps

Using global tools on AudioSnap transient markers

Editing transient markers

Using the AudioSnap palette

Synchronizing audio and the project tempo

Fixing timing problems in audio clips

Extracting MIDI timing information from audio

General editing

Using the Pool

Algorithms and rendering