A quick and easy way to add interest to almost any sound is to use a vocoder to change its sonic characteristics. In this tutorial, I'll show you how to create a vocoder freeze effect, where you freeze a vocal sound for as long as you like for breakdowns or build ups, then unfreeze it and resume playback of the vocoded vocal sample.
This effect makes use of a common feature in most vocoders called a 'freeze' or 'hold' function. This will do exactly what it sounds like and will enabled will freeze the incoming signal on a single sample until you release the button.
Using your hosts DAW's automation, you can make the disable automation point the exact same as the enable automation point on a duplicate audio or midi region. You can then move the duplicate region in time to lengthen or shorten the vocoder freeze area in between.
The steps to achieve this effect are fairly simple:
- Set up your host DAW and plug-in for vocoding.
- Set an automation point to enable the vocoders freeze function.
- Duplicate the automation and audio region and move it down in time in the sequencer.
- Change the automation point from enable to disable.
This will assure that the exact sample that the vocoder freezes on and releases on are the same, or as close as possible, to minimize an audio jump when it begins playing the audio sample again.
Freezing a Vocoder
Now that I explained how to do this effect, let me show you step by step how to achieve a vocoder freeze effect inside of Logic Pro 9 using its Evoc 20|PS.
Here's a before and after of the effect we will create:
1. Set Up Your Host DAW and Plug-in
This step will vary depending on your host DAW and the synth plug-in you are using to vocode, but the idea is you need to have the vocoder plug-in set up as a playable synth. Inside of Logic Pro using the Evoc 20 PS, you create a new virtual instrument track, and load up the Evoc 20 PS.
Next we need to have a sound source to feed into the synth via the side chaining function. I’ll use a free vocal sample I have here and drag it into the sequencer. Next inside of our vocoder synth we need to select the audio track from the sidechain drop down.
Finally, on this particular synth we need to switch it from being a stand alone synthesizer to be a vocoder for incoming audio through the sidechain. You can optionally disable the audio output of the sample you are vocoding so you just hear the processed signal, or you can have a mix of wet and dry to your preference.
2. Set an Automation Point to Enable the Vocoder's Freeze Function
Next we need to set up the automation point where you want the freeze to take place. I found that with vocals this effect sounds most pleasing and quite natural when you freeze in the middle of a vowel.
I’ll place the automation point right here, and inside of Logic Pro for an on-off MIDI signal the node will jump to the top or bottom—top for on and bottom for off. I’ll place the automation point at the top to turn the freeze button on.
3. Duplicate the Automation and Audio Region and Move It Down in Time in the Sequencer
Next I’ll copy the audio region by pressing the option key and dragging it down in time in the sequencer. Logic Pro by default will ask if you want to copy the automation data. I’ll click copy and this new version will have the automation point in the exact same place in the audio region as the original.
4. Change the Automation Point from Enable to Disable
Finally, we need to change the automation point to be in the off position. To do this, I’ll click the automation point, then press and hold the shift key on the keyboard to constrain the movement to the X or Y axis, the move the point down until it snaps to the bottom.
If we look at what we’ve created, we have an audio file running through a vocoder, and using the host DAW's automation, we set the enable and disable points in the exact same spot on the same audio file. This should give us a vocoder effect that freezes then releases the vocal sample.
I’m going to play the vocoder live on my MIDI controller as I play the project. Let’s have a listen:
As you can hear when the automation triggers the hold function of the vocoder, It freezes the sample, then when it reaches the release automation point, it resumes playback at the exact same spot that it froze at on the previous audio region.
Using a Vocoder without a Hold Function
Not every virtual synth that can be used as a vocoder has a hold or freeze function, but you can still create this effect if you have an automatable effect plug-in that can sample and hold, or that can otherwise freeze the audio track that it is on. You are essentially using the insert effect plugin in place of a built in hold function on the vocoder synth. The end effect is the same, but by using an insert effect you can easily go above and beyond by automating the other various parameters of the effect plugin.
Vocoders are a fun and easy way to add sonic interest to your production. In this tutorial I showed you how to create a vocoder freeze effect using a vocal sample.
Keep in mind you can do this effect on a wide range of sounds, not just vocals, and using a freezing effect like I demonstrated here can help add that extra variety you may have been looking for.