The fastest way to not understand synthesis is to spend three months tweaking presets. The slowest and most educational way is to start from a single sine wave and add components one at a time.
The Signal Path
A basic subtractive synthesiser does this:
- Oscillator — generates a waveform (sine, sawtooth, square, triangle). Each has a different harmonic content and therefore a different sound character.
- Filter — removes frequency content. A low-pass filter removes high frequencies; a high-pass removes low. The filter cutoff and resonance are the main controls for tonal character.
- Amplifier — controls volume.
- Envelopes (ADSR) — shape how the filter and amplifier change over time: Attack, Decay, Sustain, Release.
- LFO (Low Frequency Oscillator) — a slow oscillator that modulates other parameters, creating vibrato, tremolo, filter sweeps.
Why Learn This
When you understand the signal path, you can hear what needs adjusting. A sound that’s too harsh? The filter cutoff is too high or resonance too prominent. A sound that disappears too quickly? The release is too short.
You stop guessing and start making decisions. That’s the shift that takes you from “tweaking presets” to “designing sounds.”