Sound Synthesis Techniques

Additive Synthesis

• Concept: Creating sound by adding harmonics.
  • Achieved by stacking oscillators (often sine waves).
  • Each added harmonic changes the waveform.
• Tools:
  • Ableton's Operator: Vertical bars representing harmonics.
  • Serum: Use pencil icon in the oscillator section to draw waveforms.
• Control: Independent volume control of each harmonic for greater sound shaping flexibility.

Subtractive Synthesis

• Concept: Starting with a sound rich in harmonics and removing some using filters.
  • Low pass filter: Cuts high frequencies, making the sound less harsh.
  • High pass filter: Cuts low frequencies, useful for layering.
• Example: Start with white noise and use filters/EQ to isolate desired frequencies.

Wavetable Synthesis

• Concept: Using a table of multiple waveforms.
  • Knob to cycle through waveforms for organic sound motion.
  • Can import audio samples to extract waveforms (e.g., Serum).
• Features: Morph between waveforms for endless possibilities.

Amplitude Modulation (AM) Synthesis

• Concept: Modulating the volume of a carrier signal with a modulator.
  • Involves two oscillators: Carrier (sound source) and Modulator (controls volume).
  • Fast modulation distorts the waveform adding harmonic content.
• Ring Modulators: Similar but only the added harmonics remain; original carrier frequency disappears.

Frequency Modulation (FM) Synthesis

• Concept: Modulating the pitch of the carrier with the modulator.
  • Creates a richer sound with more harmonics.
  • Adjusting the modulator's amplitude affects harmonic content distribution.
  • Versatile: Multiple oscillators can be connected in various ways (e.g., DX7 synth).

Wave Shaping Synthesis

• Concept: Starting with a simple waveform and distorting it using a wave shaper.
  • Types: Saturation, asymmetric saturation, wave folding, phase inversion.
  • Explored more in detail in episodes about distortion and saturation.

Hard Sync

• Concept: Using two oscillators where one resets the period of the other.
  • Detuning or different notes for distinct breaks in the waveform.
  • Effective when slave oscillator is at different frequency than the master.

Granular Synthesis

• Concept: Uses audio samples sliced into tiny grains (1-50 ms).
  • Grains can be layered, played at different speeds, lengths, and volumes.
• Tools: Ableton's Granulator 2, time stretch in DAW.
  • Time stretch: Repeats grains to lengthen sound without changing pitch.

Summary

• Overview of eight synthesis types: Additive, Subtractive, AM, FM, Wavetable, Wave Shaping, Hard Sync, Granular.
• Importance of filters to manage rich harmonic content.
• Next topic: Detailed look at subtractive synthesis and filter types.