UPDATE: I've included an interactive graph I created using Desmos, a cool, free online graphing calculator, that explains FM Synthesis in much more visual way.
A couple of days ago, I did a post on a brand new synth I picked up, the Korg Volca FM. For being about 170 USD, this thing is powerful. I can't really say there's a better synth of this type today. So let's get to the chase, I'm going to explain more on how FM Synthesis makes sounds and why it sounds, in my opinion, awesome.
First, let's dive into what Frequency Modulation is. The different tones are created by making the frequency of the waveform more frequent. On the other hand, traditional analog synthesis is created by subtracting from the wave form until the desired sound is achieved.
If we look at diagram #1 to the left, different sound types are created by changing the frequency of the sound. This is achieved with operators. Operators are usually an Oscillator combined with a Voltage Controlled Amplifier and an Envelope Generator.
For FM synthesis to work, you usually need digital control and at least two operators. Diagram #2, Below, explains this in a visual manner. First, you have the Modulator, next you have the Carrier. The Modulator creates the frequency and the Carrier takes the frequency and changes the frequency of a certain point on the waveform.
Another thing that makes FM Synthesis work extremely well with digital is the fact that the Operators can be reordered to make different sounds. A specified order of six Operators is called an Algorithm. Below is the list of algorithms that are built into the Korg Volca FM.
Well, that was not the deepest dive into the complicated world of FM synthesis, but now you have some idea on how this works. It would take a whole lot more than a text book to explain this concept.
As always, thanks for reading!
Your Blogger,
AJ
You can check out my previous article on FM Synthesis here.
Here's the graph as mentioned in the UPDATE: