Modulation synthesis – Simon Hutchinson

10 January 2022

Basic FM Synthesis in Reaktor 6 Primary

Building a basic but expandable FM synthesizer in Reaktor 6, making an FM operators that we can duplicate as much as we want.

In FM synthesis, we modulate the frequency of one oscillator (the carrier) with another oscillator in the audible range. We can make an FM synth in Reaktor that’s modular and quickly expandable if we make a macro with the oscillator, an envelope, and a few special controls at the FM input.

0:00 Intro / What is FM Synthesis?
1:30 Sine Oscillator with Amplitude Envelope
3:14 The “F” Input of Sine FM Oscillators
4:20 Modulating the Frequency
5:24 Modulating the Frequency in the Audible Range
6:13 Adding Musical Controls
11:50 Combining Our FM Operators
13:01 Sideband Modulation with Envelope Control
16:12 Chaining FM Operators Together
19:48 Recap / Next Steps

Pure Data Patch from Scratch: Simple FM Synthesis Sequencer

A quick and easy Pure Data patch-from-scratch tutorial building a sequencer that plays dynamically changing timbres for each note though frequency modulation synthesis.

In this patch, we set up a simple sequence of sine wave pitches (frequencies), then a sequence of modulation frequencies of a different length, then a random patterns of deviations, creating a constantly changing series of sounds.

There’s no talking on this one, just building the patch, and listening to it go.

0:00 Sequencing the pitch of a sine wave
1:23 Creating modulation oscillator sequence
2:45 Randomizing the deviation
3:15 Audio math: modulator frequency
3:51 Audio math: deviation
4:09 Audio math: FM synthesis
4:31 Tweaking the numbers
4:52 Commenting the code
5:47 Adding delay (as usual)
6:55 Feedback for the delay
7:17 Listening and more tweaking numbers

More no-talking Pure Data jams and patch-from-scratch videos here:

8 November 2021

Are There Just 5 Types of Synthesis?

You can find a lot of lists out there on “Synthesis Techniques You Must Know!” These can be pretty compelling, but it can be helpful to take a broader look, and simplify synthesis into 5 big categories:

-Playback and Manipulation of Recorded Audio (Sampling and WT Synthesis)
-Additive Synthesis
-Subtractive Synthesis
-Distortion Synthesis and Modulation Synthesis, and
-Physical-Modeling Synthesis

By zooming out and thinking about these larger ideas, we make synthesis more accessible to people who are starting out, and we give a framework for people who are innovating new synthesis techniques.

0:00 Synthesis isn’t that complicated.
1:03 Five Categories for Synthesis Techniques
1:33 Playback and Manipulation of Recorded Audio
2:34 Additive Synthesis
2:52 Subtractive Synthesis
3:20 Distortion Synthesis (Modulation Synthesis)
4:08 Physical Modeling Synthesis
4:25 So What? / Hybrid Synthesis

Analog. Audio Multiplication, Ring Modulation, & AM Synthesis (Snazzy FX Dual Multiplier)

I got a Snazzy FX “Dual Multiplier” the other day, and thought it might be a good opportunity to talk about audio multiplication and the difference between AM synthesis and ring modulation.

Both AM synthesis and RM can be accomplished by multiplying a waveform (the “carrier”) by another waveform in the audible range You don’t need an analog multiplier to do this! You can do this in whatever synthesis environment you’re working in–Pd, Max/MSP, Kyma, Reaktor. All you have to do is multiply your signals, being mindful of whether the signals are unipolar (0 to 1) or bipolar (-1 to 1).