Using Ringshifter For Pitch Effects in Logic Pro
Toby Pitman on May 07, 2012 in Logic Pro • 1 comments
In this tip I’ll show you a cool trick for making Octave and Whammy pedal effects using Logic's Ring Shifter plug-in. The effect works particularly well with monophonic distorted guitar lines. Here’s how it works!
Ring Modulation is a great effect for making non-harmonic, clanging, metallic sounds and Sci-fi effects. The idea is you take an Input signal and multiply it with a Carrier. The output is the Sum and Difference of the two signals. In Hz this would mean if your input was 600hz
… and the carrier was 340hz
the result would be two frequencies of 260hz and 940hz.
Now these two frequencies have no harmonic (musical) relationship to each other which is why they sound discordant. This is mainly because 600hz and 340hz are totally unrelated harmonically too!
The curious thing is that if you modulate the input with a frequency that is related you get a harmonic result. This is very evident with two pitches that are an octave apart. If, I say, modulate a 400hz tone:
… with a 200hz tone (half the frequency or an octave below) you get a result an octave below:
Now don’t ask me why this is because I’m not quite sure!! :) The only thing I know is that you can use this to create an Octaver effect on guitar!
Making An Octaver Effect
Here I have a guitar riff in A. It’s fuzzed out in Guitar Rig. You’ll need to lay off the vibrato (or not) to avoid detuned ring mod effects.
On an ES2 instrument track I have the same part using a simple Saw wave an octave down.
The first thing I do is assign the synth to Bus 1 and set its output to No Output in Logic as I don’t actually need to hear it.
Next up I place a Ringshifter before my Guitar Rig plug-in.
Now I choose Side Chain for the Ring Modulator inside the Ringshifter and set the side chain to Bus 1. Turn off all the LFO and Envelope modulators and set the mix to 100% wet.
So, now the guitar signal is being ring modulated with a synth playing all the same notes an octave down.
Cool! Sounds like a Boss Octaver and not too dissimilar to a Octafuzz (which also produces Ring Mod effects).
And A Whammy Effect
So after I’d discovered that, I thought about what might happen if I applied some pitchbend to the synth. I set up the ES2 to allow a pitchbend of three octaves.
It turns out you get an effect not too far from a Digitech Whammy pedal. Here’s the part with some pitchbend applied to the ES2. It’s fairly extreme and crazy but you get the picture!
When pitchbending because the dividing frequencies are all multiples (octaves) of the guitar we still get the correct pitch information.
Try this out using different synth sounds for more crazy outcomes. Adding a high pass filter to the saw gives some really strange and broken sounding results. Mental but nice!