Track pan and volume automation

In GarageBand, you can control the panning (stereo position) and volume of each individual track using the track's mixer controls:

But GarageBand also provides the ability to automate these settings, so that you can have a track's volume or panning change during the track. It does this by means of track volume and pan curves, accessible by clicking the downward arrow button by the track name.

When you first reveal this section, the 'curve' itself (a straight line by default) is slightly faded and the indicator rectangle to the left of the Track Volume popup is black. You can click this indicator rectangle to start using the volume or pan curve, whereupon it lights up and the track mixer controls become greyed-out:

The same happens as soon as you add any volume control points (see the next section) to the volume curve, or pan control points to the pan curve.

From this point, you can't modify the mixer controls unless you turn off the track's automation by clicking the indicator rectangle and making it black. Any settings you put in before you activated the volume or pan curve are used by the curve as its starting values, but if you add any volume or pan control points then deactivate the volume or pan curve, go back to using the mixer controls, then reactivate the volume or pan curves, any modifications you made in either aren't transferred over.

To get into the details of how you actually use these curves, we'll start by looking at volume automation (i.e., programming in changes in volume).

Volume automation

When using the volume curve, you control how the volume changes by creating volume control points in the volume curve. This is as simple as ALT-clicking on the curve. You have to click on the line to create the point, then drag it to where you want it to be, rather than clicking where you want it to be to start off with:

(Notice that the selected, or newly-created volume control point appears slightly larger, as it has a blue selection halo around it.)

Once created, drag the point to where you want it. If you do this, you'll notice an odd behaviour about GarageBand's volume control points: they're sort of 'sticky' about which direction you drag them in. Once you start dragging them in one direction, either side-to-side, or up-down, they try to stick to that direction, though will change if you make a larger movement in a different direction. This isn't a bug, it's actually helpful. With these volume control points, you're working in quite a small space, and this feature saves you from transferring your mouse jitters to the volume control points.

Notice that when you click on and hold a volume control point, a helpful tooltip comes out to tell you the dB value of the volume at that point:

All that remains now is that you create all the points you want in order to create the volume effect you're after.

Deleting a point is easy, you just have to select it and hit the delete key.

You can also drag a selection box over a set of points and move them all at once. This is helpful if you, for instance, create a fade out at the end of a track then later increase the track's length. You don't have to re-create the whole fade, just select all the volume control points and drag them along. (It can be helpful to make sure the playhead is at a significant point, such as the end of the track, so you can use it's red line to line up your fade properly.)

A tip

When creating volume control points, you're most often going to be keeping a track's volume at a set level for most of the time — probably a level you have already decided on with the standard mixer controls volume knob — so it's a good idea when creating volume control points to start by creating the points that return the volume to that set level first.

To explain a bit better, say that you're going to create a dip in volume, where the volume of a track starts at its normal level, dips down for a moment, then comes back up to its normal level. To create such a dip, start by putting in the two 'normal level' points, as follows:

Then add the dip between them:

Similarly, with a fade in, start by creating a volume control point at the point where it comes up to normal volume, then put in the lower volume point to start the fade in.

Panning automation

Controlling the panning works exactly the same as controlling volume. First, change to view the pan curve by clicking the popup and selecting Track Pan:

You now create pan control points exactly as you did when creating volume control points. The only difference is that when dragging a point, the value you get up is not a dB level, but a number from -64 to +63, negative numbers indicating left-side panning, positive numbers indicating right-side panning, and 0, of course, meaning that the track is stereo-centred.

Precisely how you use these effects is up to you — individual track fades can be used to, for instance, fade all tracks but the drums out at the end. You can also use volume automation to compensate for a real instrument track where the volume of the recorded instrument changed for some reason.

The techniques described in this article can also be used on the Master Track's volume automation. For more on this, see this site's article on creating a fade-out.