I’ve spoken in the past about how synthesizers work, but I just stumbled across this new video which I think you might find helpful:
Here is a summary of the points covered:
- You start with a basic waveform – usually either sine, triangle, saw, or square.
- With a square wave, you can vary the width of the pulse. Varying the width at a regular interval is what is known as “Pulse Width Modulation”.
- Control Voltage is an electronic signal that can be passed to other parts of the synthesizer in order to control its behaviour. This is referred to as “Modulation”.
- One way to modulate a sound is by assigning an envelope to it. An envelope has four parts:
- Attack – how quickly the note reaches its full volume.
- Decay – how long it takes to go to its sustain level.
- Sustain – how the note continues while the key remains pressed.
- Release – how long it takes for the sound to fade after you lift your finger off the key.
- A filter allows you to remove part of the frequency spectrum of a sound.
- A low pass filter cuts off everything above a certain frequency.
- A high pass filter does the opposite.
- A band pass filter lets a specific band of frequencies through.
- A notch filter does the opposite.
- The resonance control boosts the frequencies close to the cutoff point.
- An envelope can be used to modulate the filter cutoff frequency over the duration of a note.
- LFO (Low-Frequency Oscillators) can be used to modulate a parameter at a regular cyclical rate.
- Running a sine wave LFO to control the oscillator’s amplitude can give a vibrato effect.
- You can change the frequency of the LFO so that it wobbles at different rates.
- Using a square wave LFO will turn the parameter off and on rather than creating a smooth vibration.
Anyway, I hope you found that interesting. If you have any comments or questions, I would love to read them, so why not post in the comments sections below.
All the best,