Harmonic Parameter in FM8

SPASMODIC

Hi,

Could someone explain in detail exactly what the harmonic parameter does in fm8?

I find it really useful for quickly conjuring up new sounds on an existing patch.

Sometimes it sounds like it stays in tune and other times it seems it doesn't.

I want to know exactly what is happening so i can control this parameter a bit better.

Jeremy_NI

@SPASMODIC It's well explained in the manual, section 4.1. What is Frequency Modulation?

A little extract:

As a pure sine wave is pretty boring from a musical standpoint, this leads us
to the extremely clever aspect of FM synthesis. Let’s add a control input to
the Operator to modulate its frequency

Feed a sine wave into that control input. A low frequency wave produces
vibrato by slowly changing the frequency over time. But an audio range signal
produces one of two results. Signals that are not harmonically-related to the
main oscillator create “clangourous” sounds. Injecting a harmonically-related
signal generates harmonics that sound more “in-tune” (Both types of effects
can be useful).
The amount of harmonics depends on the level of signal injected into the main
oscillator, and the harmonic structure depends on the modulating oscillator’s
frequency. As timbre is primarily affected by the injected signal’s amplitude,
adding a VCA after the modulating oscillator (along with an envelope generator
to control the VCA/DCA) allows predictable control over the signal, hence the
overall timbre. Our FM synthesis block diagram now looks like this.