INCLUDES AUDIO
What’s a sound without movement? LFOs are likely the most common tools at our disposal for creating movement when creating sounds or applying effects. LFO stands for low frequency oscillator – specifically, an oscillator whose frequency is typically below the human audible range (under 20Hz), although these days that frequency limit is by no means hard-coded.
You’ll most likely see LFO settings incorporated into each synth in your toolkit because of how common they are and how many creative options they provide us. We can map them to modulate most synth patch parameters (like pitch, volume, filter cutoff, and effects processing–like reverb) although some synths are designed with LFOs fixed to one or multiple parameters.
Unlike the single cycle of an envelope filter (another similar modulation tool featured in most synths), LFOs allow us to add constant cycling movement, texture, and depth to our sound designs by consistently modulating their mapped parameters across time, according to their specified frequencies. An envelope signal typically ‘plays’ once alongside a note, starting and ending coincident with it, while an LFO signal often feels more constant, oscillating even when a note hasn’t yet been played.
Some LFOs – including the one in Ableton’s Auto Filter – also allow us to set the LFO rate at a musical measurement (like 1/4 bars or 1/2 bars), instead of a fixed frequency, so the modulation applied will automatically be in sync with your project tempo. This is especially helpful when creating a desired rhythmic pulse. Many LFOs also allow us to change their wave shape (eg, sine, triangle, and sawtooth) to customise
