Lesson 1: Additive Synthesis

Create a new pd program called add_synth

Here we are adding two sine waves together

The first sine wave is at 440 Hz

The second sine wave is at 880 Hz

The second wave has its volume reduced to 0.75 %

We then add both sine waves together and reduce their combined volume to 0.25 % (if we added two waves at full volume, it would be twice as loud as 1 wave… that is really loud and can hurt our ears and damage our speakers)

The * by itself does multiplication

The * followed by a ~ controls the volume level

Number

Box

Send both oscillators to an array using tabwrite~

You can change the “Size” of your array to see more of the waveform, try messing around with that

By adding two waves together, we have changed the waveform and thus changed what we hear

Let’s break down how this addition really works, let’s send each oscillator to a separate array

When multiple frequencies are combined, the main frequency (typically the lowest) is called the fundamental, the other tones (typically higher in frequency) are called the overtones

By visualizing the fundamental (440 Hz), and the overtone (880 Hz), we have inadvertently learned what frequency really means

Frequency is the distance between peaks of the wave, overtones peaks happen twice as frequently as the fundamental peaks

Adding waveforms together is a very visual math

When the peaks meetup, you get an extra big peak

When the valleys meetup, you get a deeper valley

What do you think is happening at these 2 points

Now try adding a sine wave to a saw wave (phasor~), then send the signal to an array. What do you think it will look like?

The saw wave makes my sine wave choppy

This sounds more ‘aggressive’ than a typically smooth sine wave.

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I also adjusted the frequency of my saw wave, feel free to mess with that as well.