Logic Pro From A to Z – U is for Utilities
Utilities, as the word suggests, are useful for a variety of purposes. Nestled inside of Logic Pro’s plug-in menu, in the Utilities directory, is an extremely useful and underrated little gem: The Test Oscillator. In this article I’ll explore ways of using it to create colourful pitch riser effects.
The Test Oscillator
Unless you enjoy the sound of a constant sine wave at 1000 hz, press the bypass button as soon as you call this plug-in up on an Audio Track. Press the Sine Sweep button at the lower left; this is the mode we’ll be using it in for this exercise. The first thing to set is the value in the Time field. The default is ten seconds, but this will likely be too long.
Use the Delay field in the Region Inspector to determine the value of musical subdivisions in milliseconds in order to sync your riser to the tempo of your song. For example, at the tempo of 130 bpm, a whole note works out to 1,846 ms. The resolution in the Test Oscillator’s time field is somewhat course; it will round it off to the nearest decimal point. So if you want a riser for a full bar at that tempo, double click the time field in the Test Oscillator plug-in and enter a value of 1.8.
Under the Start Freq and End Freq fields, enter the values that you want the riser to start and end with. To correspond with the key of your song, here is a useful chart of musical notes expressed as frequency values. In my example I am setting up a three octave sweep up from G3 to G6; 196 hz to 1568 hz. To get a downward riser, simply invert the values so that the value in the Start Freq field is higher than in the End Freq field. Values entered here will also be rounded off.
Adding Phase Distortion
Unless you want a bland sine wave sweep as your riser, you’ll need to add some effects processing to make it more interesting. I like starting with the Phase Distortion plug-in. It subtly breaks the vanilla sound apart nicely for additional processing to follow. Enable the Test Oscillator plug-in, and experiment with different Phase Distortion settings by pressing the Trigger button on the Test Oscillator. You’ll hear the sweep start coming to life. The Clip Distortion is also great for adding some nice phat Fuzz to the sound, and works great following the Phase Distortion.
Adding Space Designer’s “Warped” Presets and Tremolo
Until you add add on some time and space processing though, it’s still going to sound like a processed sine wave. Delay Designer and Space Designer’s “Warped” presets are great for these types of uses where you want to really obscure the original quality of the sound. And Logic Pro’s Tremolo plugin is great to add movement in the stereo field. The wilder the better! I like extreme settings to create an almost buzzing type of effect. Here are the settings I’ve used, followed by a short clip with all five plug-ins in place on the Test Oscillator track: Phase Distortion, Clip Distortion, Delay Designer, Tremolo, and finally Space Designer.
The Sweep Trigger Parameter
Understanding how to trigger this effect in context requires nothing more than some simple automation. Enable track automation and call up the Sweep Trigger parameter from the Test Oscillator’s automation menu items. It is simple bypass style automation with only two values; on and off. Here is an example of this riser effect in a musical context with some sixteenth notes and thirty second notes on snare drum added underneath.
Ultimately the Utility menu remains a useful place, not only for when you need to flip the phase of a track, or route some external audio into your signal flow; but also for creative inspiration.
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