FM sidebands are spaced by the modulator frequency on either side of the carrier frequency

The FM spectrum consists of a central component at the carrier frequency fC, flanked by sideband partials at fC ± k·fM for all integers k. Sidebands are evenly spaced by fM around the carrier. Unlike additive synthesis where each partial is independently controlled, FM generates all sidebands from a single modulator frequency — a computationally efficient way to create rich spectra. The amplitude of each sideband depends on the modulation index and the sideband order.

Examples

Carrier at 500 Hz, modulator at 200 Hz: partials appear at 100, 300, 500, 700, 900 Hz (negative frequencies fold back). Audibly this sounds like a timbre rich in upper harmonics.

Assessment

Given fC = 440 Hz and fM = 110 Hz, list the first five partial frequencies on each side of the carrier.