Thursday, May 21, 2009

Logic's Vocoder Part Two: Less Traditional Uses

In the previous installment, I showed you how to use Logic's EVOC-20 Tracking Oscillator plug-in to do traditional vocoding: imparting the speech patterns of spoken or sung vocals on a synth sound for the traditional 'robot vox' made famous by bands like Kraftwerk. You may have already figured out that synth sounds and vocals aren't the only two things you can combine. In fact, you can vocode anything that makes a sound with anything else that makes a sound. Some combinations are more useful than others, though, so here are a few suggestions to get you started.

• Follow the procedure outlined in part one of this tutorial, but instead of using a speech or vocal sound file, load up a drum loop or drum machine instrument. The result is a rhythmic pad part with a spacey, otherworldly quality to it. Here's an example:

That sounds pretty complex, but all it took was a beat coming from Microtonic using a pad from Alchemy as the carrier. And your carrier needn't be melodic. Try using white noise, and you'll get a synthetic white noise rhythm that would be a nightmare to recreate on all but the most well-equipped modular synths.

• Next, let's try changing our pad instrument to another drum loop. Keep everything exactly the same as the example above, but change the instrument track that was playing the pad sound to a drum machine instrument or drum loop player so we have one drum beat vocoding another. The result is a cool, totally synthetic sounding loop like this:

In fact, vocoding two similar types of signals can give interesting results outside of drum beats. On the album I produced for SD6, there is a song called "We Are As One". During a breakdown, both the male and female vocals sang the same line, so I vocoded one with the other... literally making the two parts into one.
Yes. I am a geek.

• You might have wondered if it's possible to vocode a signal with itself, and indeed it is. The results vary a bit, but you can get everything from filter and flanging type effects, to more synthetic sounding timbres. Simply set your ANALYSIS IN and SYNTHESIS IN to the same setting. In this example, I've set them both to TRACK, so a drum loop from Stylus is vocoding itself:

As you can guess, there's no limit to how you can combine different sounds for all sorts of unique and interesting sounds. Have fun experimenting, but keep in mind that some sounds (an 808 kick, for example) can REALLY drive the filters in the vocoder, so keep your volume levels conservative while you're experimenting lest you blow out your speakers.


Will C. said...

Those not using Logic might want to try the TAL Vocoder for an easy-to-use VST solution.

Adam L said...

It amuses me to no end that looking up "vocoder white noise" returned a result of a post by you, Tom. As usual, you gave me some ideas which I am going to shamlessly exploit for my own purposes.

DLF said...


Thanks for blogging on the Evoc 20. I'm in the midst of a song that needs something like this, and I'm glad I came across it today!

Hopefully I can implement what I've learned here. Thanks again!