FM SYNTHESIS UNLEASHED

Frequency Modulation (FM) Synthesis is a method of generating sound that allows for a huge amount of control, leading to a diverse array of sounds, lifelike or abstract. At its heart, the concept of frequency modulation is very simple. Just as you may modulate an oscillator’s pitch on a simple synth setup, leading to the slow undulation of pitch in the notes played, FM takes the same concept further. By ratcheting up the frequency of that pitch modulation into the audible range, the ‘Low Frequency’ part of the ‘Low Frequency Oscillator’ is surpassed, leading to a complete tonal change of the original oscillator. As a synthesis method, FM is great for a number of tasks, including creating drums and percussion, inharmonic bell tones, electric pianos and a lot more.

FM Synthesis was conceptualized in 1967 by John Chowning, who theorized that synthesizers could produce identical recreations of any organic sound, from birdsong to ocean waves. Chowning’s theories are summarized in his 1973 ‘The Synthesis of Complex Audio Spectra by Means of Frequency Modulation’ – essential reading for any synth geek – where he explains how any sound can be broken down into objective mathematical components. This math can then be recalculated by a machine, and converted back to sound.

Before the creation of FM, most synths worked by having one or more parallel oscillators, independently producing full harmonic signals, sent into filters for further subtractive shaping. This setup didn’t have the capability to produce the waveshapes as per Chowning’s theory, though.

The key difference with FM synthesis is that all oscillators are operating at frequencies in the audible frequency range. Previously Low Frequency Oscillators