Investigative Intro

In what way are these musical instruments similar?

They are all synthesizers, that allow the user to change the wave form and wave shape
They all have ways to adjust pitch, volume, and timbre
They all have piano keys are a function of playing them

What controls are common to them?

Synth 1 and 3, you can adjust the amplitude ,filter, and change the low frequency oscillator
Synth 1, 2, 3, and 4 all have adjustable ENV's
Synth 3 and 4 can adjust the VCO
Synth 2 and 4 can change the type of instrument

Can you determine the function of each one of the controls? List and describe if possible

The oscillator is for changing the waveform
The amplifier is for changing the volume of the wavelength
The LFO is for changing the lower half of the wavelength
The VCO is for changing modulation and pulsation
The VCF is for changing the frequency
The ENV is for changing attack, delay, sustain, and release


Create - Something that generates sound
Change - something that can change sound
Amplify - something that can make the sound loud enough to be heard

Three Components
VCO - Voltage Controlled Oscillator; creates sound
VCF - Voltage Controlled Filter; changes sound
VCA - Voltage controlled Amplifier; makes it loud enough to be heard

In Simplest Terms
The oscillator creates a waveform - VCO
The filter rounds down the wave to the requested amount of brilliance - VCF
The wave is amplified by the amplifier to the requested sound level - VCA

Tools to Shape the Sound
The Envelope - attack, decay, sustain, release. The envelope is a control signal that can be applied to various aspects of a synth sound, such as pitch, filter cutoff frequency, and overall amplitude. Envelope generators are used
to help the synthesizer shape the sounds. They allow you alter sounds by sending a varying control signals to the synth;s VCA and VCF.
The LFO - low frequency oscillator. These oscillates are not use to make sounds by themselves, they add a low frequency to one of the three main modules: VCO. VCF, VCA. Simply: add a second wave to an existing sound to get an interesting effect

Synthesizer technology is broken up into two categories: "analog" (uses electricity) and digital" (uses binary)

2+ Oscillators
Low Frequency Oscillator (LFO)
2 Envelope Generators
Voltage Control Amplifier (VCA)

Creating Sound
When a key is depressed on the keyboard

VCO - Voltage Controlled Oscillator
An electrical device that creates a frequency by a voltage input
Altering te voltage - alters the produced pitch
Provides simple source waveforms simultaneously
Oscillator produces sawtooth and then other waveforms derived
Rectify saw ––> triangle
Hard clip saw ––> sqaure
Soft clip triangle ––> sine

First Pathway
The oscillator generates the desired frequency and waveform and then routes an audio signal to the voltage Control Filter (VCF)
Can create all waveforms

Second Pathway
The keyboard has also sent control signals to another part of the synthesizer, the envelope generators
There are usually 2 envelope generators in a synthesizer. One controls the VCF and the other controls the VCA

Sends on and off messages to signifying that a key has been pressed

A device for eliminating selected frequencies from the sound spectrum of a signal and perhaps (in the case of a resonate filter) increasing the level of other frequencies
Traditional analogue filter types: high-pass, low-pass, band-pass, notch

The process of sending a programmed signal to a sound source as to change the character of that sound
An LFO can be added to any of the three modules to change the sound

After Touch
The ability to play multiple keys by using generated data

Robert Mooge

Modular Synthesizer - all is comprised of separate devices

Normalled Synthesizers - everything was located in one box and already connected

Audio Mulch Research

Arpeggiator - plays a custom arpeggio on a loop
Bassline - creates a reating melodies and can use the using the notes from what you plug into it to make a bass track
Bubble Blower - scrambles the selected music file
Drums - uses file drum kit sounds to create a beat
10 Harmonics - allows you to change and alter a sine wave using different harmonics
Loop Player - loops a selected file and change set certain mesures and time
Risset Tones - consistently plays a loop of raising or falling harmonics
Test Generator - lets you alter the frequency of a sine wave of noise fora a test

5Combs - filters the sound coming through and lets you alter the sound
MParaEQ - an equalizer that allows you to change the high and low frequency
Nebuliser - a filter that chops up the sound and and a water sound
ReissetFilters - adds a gilding and wet sound
South Pole - has 3 envelops and 2 LFO's for changing the amplitude and frequency of the sound
SParaEQ - same as MParaEQ but solo instead of mono

Canon Looper - loops sounds in different layers
Digi Grunge - distorts the sound
DLGranulator - scrambles the sound
Flanger - creates a sweeping sound within a range of frequencies
Frequency Shifter - changes the frequencies within the range
Live Looper - records and plays back up to 16 sounds
Nasty Reverb - gives a reverb effect
Phaser - sweeps the sound within the given range
PulseComb - chops up the sound and pulsates it
Ring AM - changes frequency to get a metallic sound
SDelay - adds a delay and echo
Shaper - adds distortion and a ping-pong ball sound
SSpat - makes it sound like the sound is moving

Audio Mulch Song


Audio Mulch Song

Ableton Drum Kit


VCO - voltage control oscillator; creates frequency by a voltage input
VCF - voltage control filter; changes the sound
VCA - voltage controlled amplifier; makes it loud enough to be heard
ADSR - attack, delay, sustain, release; helps shapes the sound wave
LFO - low frequency oscillato; don't make sounds by themselves, but add a low frequency to one of the three main modules
Low pass filter - allows lower frequencies to pass, but cuts off higher frequencies
Frequency modulation - sending a signal to a sound source to change the character of the sound
Mod Wheel - the wheel on the keyboard; adjusts the sound
After Touch - how hard you hit the keys depends on how loud the sound is on a keyboard

Digital Waveguide Synthesis

Digital waveguide synthesis are "computational physical models for certain classes of musical instruments (string, winds, brasses, etc.) which are made up of delay lines, digital filters, and often nonlinear elements." Which is a synthesizer that not only reproduces instrumental sounds with greater consistency, but also allows synthesizer players to add things such as vibrato or variations in pressure and speed. It manages this by introducing short bursts of a wavelength, then is delayed and filtered. That wave is looped back and played again. You can adjust pitch so that it sounds as realistic as possible. But this is all done digitally and without the need of acoustic waveguides such as long metal pipes or rods.
Digital waveguide synthesis was developed by a Stanford student, Julius O. Smith III.
Digital waveguide synthesis is an extension of the Karplus-Strong algorithm. The Karplus-Strong synthesis loops a short waveform through a filtered delay line to simulate the sound of a string being hit or plucked, or some types of percussion.
Julius O. Smith III made a deal with Yamaha in 1994 to put his digital waveguide synthesis into their keyboards. This was the first time that synthesizers would use this algorithm to emulate sounds.

An example of digital waveguide synthesis tuning the pitch to make it sound more realistic

Karplus-Strong model

Digital waveguide model

Other Projects

Additive Synthesis: the addition on multiple oscillators together to create a new sound

Subtractive Synthesis: to strip away frequencies through the use of a filter to create a new sound

FM Synthesis (frequency modulation): one sound is altered by superimposing another sound upon it. In the VCO to alter after the frequency content

AM Synthesis (amplitude modulation): using the amplitude change of one signal to alter the waveform of another

Sample Base Synthesis: record a sound sample and assign it to a note on a keyboard to trigger it. All digital

Digital Waveguide Synthesis (wavetable synthesis): take a sound, analyze it, assign each part toa quadrant on a table. Pick a quadrant and hear a sound

Physical Model Synthesis: create an algorithm to represent the actual acoustical properties of an instrument

Linear Algorithmic Synthesis: the use of math to create abstract sounds and chance music

Formant Synthesis: analyze a sound, change the timbre of a sound by altering the resonant chamber, used for emulation of speech

Granular Synthesis: sounds are broken into little grains ands reorganized to create new sounds

Vector Synthesis: four synthesizers into one xy pad

Unit 3 Test

1. What is your name?
Colin McLeish

2. What does VCO stand for?
Voltage controlled oscillator

3. What is the function of a VCO?
Creates frequency by a voltage input

4. What module is used to alter the sounds timbre?

5. Which module is used to amplify the sound?

6. Name the four parts of the typical envelope (in oder)
Attack, sustain, delay, release

7. What part of the envelope would you alter to make the start of the sound "pop"? (the initial part of the sound has a greater amplitude then the rest)

8. This device adds a wave to an oscillator to alter the sound often emulating the vibrato or tremolo effect

9. What is the function of a high pass filter?
To allow the higher frequencies to pass through and the lower frequencies are cut

10. What is the function of automation
A programming device that allows a certain parts to turn on and off

11. What tool would I use to send the sound to the left speaker only?

12. What device is needed when one wants to use multiple audio devices at the same time and adjust their volumes?

13. What is the difference between analogue and digital synthesis?
Analogue is electronic and digital is binary

14. What is a modulator?
Something that changes another sound

15. What is a mod wheel?
Controls how much you modulate something

16. What is an arpeggiator?
Plays a custom arpeggiator on a loop

17. Put the following devices into the appropriate order

18. What type of synthesis did we use to replicate the sound of a drum kit?
Additive synthesis

19.What type of synthesis uses a mathematical pattern to create sound?
Linear algorythmic

20. What part of the envelope would need to be altered to get the sound to start slowly and smoothly

21. Change the _ and have your sound end smoothly and take long to stop.

22. What is the keyboard shortcut for a screen shot?

23. Which file would not upload to your wiki: 23 MB wav file, or 45MB wav file?

24. What effect would be added in order to make your sound appears to come from a large hall?

25. What effect gives you a type of echo?

26. What tool allows you to alter the frequency content of a sound

27. What are three acoustical properties of the snare drum that were replicated in Ableton?
Tom, stick, white noise

28. Why do we have to know this information?
To pass the test

29. Name at least 3 different types of synthesis?
AM synthesis, FM synthesis, Digital wavguide synthesis?

30. What bribe can you give my to get an 'A' in this class?
One hug