Sampling BTEC Level 3 Extended Diploma in Music Technology Year 1 Sound Creation & Manipulation Modulation – LFOs & Envelopes

Learning Outcomes Recall modulation components of a sampler and describe their function: - Envelope Generator - Low Frequency Oscillator (LFO) Apply modulation techniques to a sampler patch to modify the sound.

Envelope generators Envelope generators are standard features in many synthesizers and samplers. Envelopes can be used to control various parameters. E.g. Volume, Filter controls, FX. Envelopes control these parameters in a Linear fashion (from point A to point B)

Envelopes - ADSR Attack (time) Decay (time) Sustain (level) Release (time)

ADSR Control – Volume (Amp) Compare the following volume (amp) ADSRs Strings (no release) Strings Piano

More than just a volume control ADSRs can be used to control many things (volume, pitch, filter, other synth parameters) For effects that requires Linear control (one way only) E.g. Falling pitch FX – classic cartoon sound Basic version of cartoon drop sound FX – Oscillator pitch to envelope with long attack time

LFO – Low Frequency Oscillators Like envelopes, LFOs are a standard feature of synthesisers & samplers. Envelopes = Linear control (one way) LFO = Cyclical control – (Like a pendulum) The middle of the pendulum represents the unmodified signal i.e. no effect. The far edges of the pendulum represent the signal when it is fully modulated.

LFO Controls Sync or Free Rate (speed) - Free = cycles per second (Hz) - Sync = Note value (1/4, 1/16, 1/8d, etc) Delay Shape (Sine, Square, Saw, Noise, Inverted waveforms An example: If an oscillator’s pitch is routed to an LFO by 2 octaves and the LFO is running free at a speed of 1 cycle per second (Hz), then the pitch of the oscillator will move between root position and +/- 2 octaves every second. If the LFO shape is a sine wave then this will be a smooth fluctuation. + 2 oct - 2 oct Root

Why would we use an LFO? LFO – Low Frequency Oscillators Tremolo Vibrato Filter Modulation To add movement to sounds. To add a rhythmic element to a sound. Dub Step Bass! Route LPF cutoff to a tempo synced LFO. Automate LFO speed throughout track. Special FX (e.g. Sirens, Helicopters) – Cyclical FX

Task Modify sounds using the tools we’ve covered using NN-XT. Use Envelopes and LFOs to modify parameters on individual samples within NN-XT. Pitch to LFO Filter to LFO Pan to LFO Volume to LFO Amp (volume) envelope Pitch to envelope Filter to envelope