MUSC1010 – WEEK 6

MIDI and Sound Synthesis

Controlling Track Levels (to prevent clipping)Sometimes you may find that certain instruments (particularly those that use a sweeping filter or flanger) clip in the track volume stage, even when they are turned down considerably. In this instance you may consider adding a limiter to help control the peaks. Use the MAXIM plugin or the Digidesign Compressor/Limiter III, with the preset “Brickwall limiter”. Adjust the Threshold and Gain as necessary.

Mixing Down• Select the amount of time that you want to mix down (use GRID mode, and enable minutes/seconds view)• File > Bounce > to Disk• Change the Format to “Stereo Interleaved”• Use File Type “WAV”• 16 bit, 44.1kHz• Convert After or Bounce

Myspace Music

Oscillator Filter Amplifier

Subtractive Synthesis

EMS Synthi100

UCSC Moog modular system

Moog demo LP

Types of waveform

This waveform contains all harmonics and produces a bright and rich sound. The Sawtooth is perhaps the most "general purpose" of all the available waveforms.

A square wave only contains odd number harmonics, which produces a distinct, hollow sound.

The Triangle waveform generates only a few harmonics, spaced at odd harmonic numbers. This produces a flute-like sound, with a slightly hollow character.

The sine wave is the simplest possible waveform, with no harmonics (overtones). The sine wave produces a neutral, soft timbre.

Noise can be white, pink or red/brown. The most common noise used in synthesizers is white. White noise is the sum of random frequencies across a specified bandwidth.

Noise

Filter controls harmonic content

Overtones and Harmonics are “waves within waves”. They are of greater frequency than the fundamental frequency of the wave. Different harmonic content is why a sine wave at 440Hz sounds so different to a sawtooth wave at 440Hz. Harmonics are generally the integer multiples of the fundamental frequency of the wave (2f, 3f, 4f etc.)

Low Pass FilterMost common type is the

Increasing the resonance setting accentuates frequencies around the filter cutoff point

Amplifier controls the dynamics of sound production via a volume envelope

The variables of the envelope are (A) Attack (D) Decay (S) Sustain (R) ReleaseBy varying the Attack, Decay, Sustain and release you can imitate the sound production of various instruments;

Instrument Attack Decay Sustain ReleaseSmooth strings 10% 5% 90% 10%Pizzicato strings 2% 0% 0% 10%Piano (hold pedal) 2% 0% 0% 50%Church organ 2% 0% 100% 2%

Common Abbreviations

Osc - Oscillator.LPF - Low Pass Filter.HPF - High Pass Filter.

Amp - Amplifier Env - Envelope.

Mod - Modulation.LFO - Low Frequency Oscillator: usually used for modulation.

ADSR - Attack, Decay, Sustain & Release: the typical components of an envelope

It is possible to use a filter and an envelope to create percussion sounds.

A snare sound can be created by using a short, sharp envelope on white noise.

A kick drum sound can be created by combining a very short, low-pass-filtered white noise attack, with a low frequency sine wave.

Fairlight CMI “Digital Sampling Instrument”

As used by;John Farnham – You’re The Voice

Peter Gabriel – Shock the Monkey

Stevie WonderMichael Jackson

Duran Duran

Roland TR 808 Drum Machine

Beastie Boys – Brass Monkey

Afrika Bambaata – Planet Rock

Kelis - Bossy

Clavia - Nord Lead

As used by;Fatboy Slim

Nine Inch NailsDepeche ModeMouse on Mars

Maroon 5Dr. Dre

FOURIERIt was the mathematician Jean Baptiste Fourier (1768-1830) that first postulated that a complex waveform could be expressed as the sum of a series of sinusoidal waves. The mathematics behind modern day digital equalizers is heavily rooted in Fourier’s theory.

Two applets that demonstrate Fourier’s theory;http://www.falstad.com/fourier/http://www.nst.ing.tu-bs.de/schaukasten/fourier/en_idx.html

Polyphony is the number of simultaneous notes that can be soundedA monophonic sound (polyphony set to 1) is usually used for bass lines. If you are using a monophonic sound the

Portamento setting determines the amount of “slide” or “glide” in pitch occurs between successive notes.

The Amplitude Envelope What settings would you use to imitate the sound of;

1. an acoustic piano?2. a church organ?3. a violin?4. A harpsichord?

ADDITIONAL SOUND SAMPLES

You are invited to explore the extensive collection of free sound samples available at www.freesound.org. This is an excellent source of sound samples for non-commercial purposes. If you use one of these samples in assignment 3, please acknowledge the sample's author in the "comments" section for that track.