{"id":17326,"date":"2021-07-16T17:45:47","date_gmt":"2021-07-16T21:45:47","guid":{"rendered":"https:\/\/splice.com\/blog\/?p=17326"},"modified":"2025-05-29T13:28:59","modified_gmt":"2025-05-29T17:28:59","slug":"what-is-fm-synthesis","status":"publish","type":"post","link":"https:\/\/splice.com\/blog\/what-is-fm-synthesis\/","title":{"rendered":"What is FM synthesis?"},"content":{"rendered":"\n

Illustration:<\/strong> Filip Fr\u00f6hlich<\/strong><\/a><\/p>\n\n\n\n

FM (also known as frequency modulation) works on a simple concept in order to generate a wide range of sounds spanning gritty basses, metallic percussion, distorted effects, and more.<\/h2>\n\n\n\n

When it comes to signal processing, modulation<\/strong> simply means changing certain properties of a periodic signal (like a sine wave) over time. These could be elements like amplitude (gain) or frequency (pitch), and modulation has made it possible to send audio over long distances by means of AM and FM radio. What\u2019s even cooler is that by modulating frequencies, you can design complex and interesting sounds from scratch! Below, let’s explore how FM synthesis works and how it’s used in music creation today.<\/p>\n\n\n\n

How FM synthesis works<\/h2>\n\n\n\n

Frequency modulation requires two things in order to work: a carrier wave<\/strong> and a modulator <\/strong>(or signal<\/strong>) wave<\/strong>. The modulator wave directly affects (or ‘modulates’) the frequency of the carrier wave based on its own frequency.<\/p>\n\n\n\n

If you\u2019ve ever used the LFO<\/strong> (low-frequency oscillator) on a synth to create a vibrato effect, that\u2019s a type of modulation since the LFO is periodically moving the pitch of the wave up and down. Now imagine increasing the rate (in other words, the frequency) of that LFO way higher\u2014the vibrato effect on the carrier wave starts to change it into a much different sound that can be really tough to synthesize using other synthesis techniques.<\/p>\n\n\n\n

\"An<\/figure>\n\n\n\n

The sound of FM synthesis <\/h2>\n\n\n\n

Check out the audio below to hear what happens when we connect two sine waves, use one to modulate the other, and increase the modulating wave\u2019s frequency:<\/p>\n\n\n\n