Using a Send and a Bus to Create Reverb in Soundtrack Pro
[ This article was first published in the January, 2011, issue of
Larry's Monthly Final Cut Studio Newsletter. Click here to subscribe. ]
A while ago, I wrote about how and why to create submixes in Soundtrack Pro.
While submixes can be used for reverb, a better way is to use Sends and Busses. This provides greater control and more flexibility than a Submix, but it is a bit trickier to understand.
The reason we use Busses for reverb is that if you apply an effect to a Track, that effect ends when each clip in the Track ends. So, while Tracks are the perfect place to put EQ or Limiter filters, they are not good for effects that need to linger after a clip ends.
Reverb, for example, needs to ring-out after the clip ends. If you put it on a Track, the effect chops off the instant a clip ends.
Try it, and you’ll see what I mean.
This means that we need to apply a lingering effect to either a Submix or a Bus. Both will work, but Busses are better.
To keep this simple, I’ve created three audio tracks in Soundtrack Pro, two that will have reverb added and one that won’t.
I’ve labeled clips and added audio files. There is NO significance to the track names or the audio clips. You can use your own names and clips.
A Bus is an audio channel that carries audio from one place to another. You can’t put clips in a Bus, only in a Track. Specifically, a Bus carries audio from one, or more, tracks and delivers it to a Submix.
The benefit a Bus provides is that you can route multiple Tracks into the same bus so they can all be processed the same way.
You regulate how much audio from each track goes onto the Bus using a Send. The easiest way to think of this is the Send is a faucet that determines how much water goes into a hose, the Bus. And the hose carries the water to its destination, say, a swimming pool. The Submix is the destination.
By default, there are no Buses in a new Multitrack project. So, let’s create one by selecting Multitrack > Add Bus (type Control+Cmd+T).
A new Bus is added below all the tracks and above all the Submixes. Just because I can, I’ll rename this Reverb.
There is no practical limit to how many busses you can create. However, we generally have more tracks than busses in a project.
With the Bus selected, go to the Effects tab and add a reverb effect. In this example, I’m using the PlatinumVerb.
When the effect opens, don’t panic. There are far more controls on here than you will ever use!
Click the Show Presets button in the lower left, then twirl down the User Presets, select something, and click Apply Preset in the lower right corner.
Changing presets is as easy as selecting and applying a different Preset.
The purpose of this Bus is to be “All Reverb, All The Time.” So, to make this purely an effects track, lower the Dry setting to 0%. This prevents any “normal” unprocessed audio from being heard on the Bus.
Then, raise the Wet setting to 100%. This means that ONLY audio with reverb applied will be heard.
If you were to play your sequence, you would not hear any reverb. This is because we haven’t routed any audio to the Bus, yet.
That’s what a Send does.
While there are several ways to create a send, an easy one is:
- Select the Bus
- In the Left Pane, select the Tracks tab
- Control-click in the top portion of the Track control and select Add Send > To Reverb.
What you’d just done is create the “faucet” that determines how much audio gets sent to the Bus and which Bus that audio goes to.
With the Bus still selected in the Timeline, go to the Effects tab and notice that the Send controls now appear.
Adjust the Level setting until the amount of reverb you are adding sounds right. There is no perfect number here. Whatever works for you, as long as your total audio levels don’t go over 0 dB is fine.
A little lower down in the Send control is a pop-up menu titled Post-Fader. This allows you to control whether the reverb level is constant, or based on the gain control for that track.
The easiest way to see how this works is to set it both ways and listen to the difference as you move the volume slide for the TRACK up and down. In one case, post-fader, the reverb changes as the volume changes. In the other case, pre-fader, it doesn’t.
We generally run Sends as Post-Fader, but every project is different.
An easy way to test your effect is to solo both the track and the bus. This way, you hear both the unprocessed audio (on the track) and the effect (on the bus). Adjust the Send level until you are happy.
Keep in mind that Busses work best with effects that linger after a clip ends. And use the Send to regulate how much of the effect you hear.
I don’t use Busses all the time, but I sure do appreciate them when I do.