These are notes for two guest lectures I gave to Professor Joseph Koykkar’s sound design classes at UW Madison on April 4, 2016. Various ways of generating sound from simple building blocks like sine waves and pink noise are explored: beating sine waves, filtered noise, extreme pitch shifting and time stretching, and the application of delay, reverb and modulation. Along the way, a variety of useful Pro Tools routing and automation techniques are applied, and a number of standard plugins are put to use. Various helpful key commands are demonstrated as well. I have included a number of audio examples.

The material is broken into six sections:

Beating Sine Waves, Filtered Noise, Automation, Elastic Audio Mangulation of a Sine Wave, Elastic Audio Mangulation of a Square Wave, Elastic Audio Mangulation of a Drum Loop.

Beating Sine Waves

No sine waves were harmed in the preparation of this presentation.

  • Make two sine wave clips with different frequencies
    • When heard together, the two tones will "beat" at the difference frequency
    • i.e. 264 - 261 = 3 Hz beat frequency
  • Make an empty selection
  • Start End Length fields can be useful for making exact selections
Four second selection

Image startEndLength2</IMG>

  • Audiosuite Signal Generator - select signal type, set frequency and level, Render
Audiosuite Signal Generator

Image sigGen</IMG>

  • Use "New Track" for quick and easy routing
    • Select all tracks you want to route
    • Hold down Option + Shift
    • Click on the output of one of the tracks to be routed
Route to New Track - Output Path Selector

Image newTrack</IMG>

  • Select "New Track"
  • Choose Track Type and Name
Route to New Track - Select Track

Image newTrack2</IMG>

  • Audio Track allows you to "print" to a new audio file
  • Aux Track is good for further processing

End result:

Source tracks routed and recorded

Image swBeat</IMG>

  • A few useful commands
    • Option + F zoom a selection to screen width
    • Command + [ or ] Horizontal zoom
    • Option + Command + [ or ] Vertical zoom
    • Option Click - set control to default
    • Tab to Transient - very useful, can be combined with option and shift keys
Tab to Transient Enabled

Image tt</IMG>

  • Commands Focus Mode:Provides single-key "hotkey" commands
Commands Focus Mode
Image cfMode</IMG>

  • A key trims from clip start to cursor
  • S key trims from cursor to clip end
  • P and ; move selection up and down. Very useful.
  • Shift + S, M, R - solo, mute, record enable all tracks where cursor resides
  • Option Drag drags a copy of a clip, plug-in or send

Filtered Noise

Interesting pitched sounds can be created by applying very sharp filters to noise signals:

  • Audiosuite Signal Generator : Select desired length, Pink or White noise at -6dB, Render
  • Air Vintage filter
Air Vintage Filter

Image vintageFilter</IMG>

  • Set cutoff to desired frequency
  • Set resonance to around 90
  • Mode: BP (Bandpass Filter)
  • Option drag plug-in to put two or more in series
  • Duplicate tracks - Option Shift D (or right-click)
  • Fancy: set frequencies to chord notes:
Interval Ratio Multiplier Example
Unison 1:1 1 440 Hz
Major second 9:8 1.125 495 Hz
Minor Third 32:27 1.185 521 Hz
Major Third 81:64 1.2656 557 Hz
Fourth 4:3 1.333 587 Hz
Tritone 1024:729 1.405 618 Hz
Fifth 3:2 1.5 660 Hz
Minor Sixth 128:81 1.58 695 Hz
Major Sixth 27:16 1.6875 743 Hz
Minor Seventh 16:9 1.778 782 Hz
Major Seventh 243:128 1.898 835 Hz
Octave 2:1 2 880 Hz


Automation can be used for almost anything imaginable in Pro Tools. Here we will change the pitch of one of the filtered noise tracks for a musical effect.

  • "Power Claw" (Control + Option + Command) - click on a parameter (Cutoff in this example) to quickly automate it
Power Claw

Image powerClaw</IMG>

  • Set ruler to Bars Beats
BarsBeats Ruler

Image ruler</IMG>

  • Set track to "Ticks" (more on this in a moment

Image ticks</IMG>

  • Set grid to 1 Bar
Grid set to 1 Bar

Image grid</IMG>

  • Select Grid Mode (press F2)
  • Make a 1 bar selection, use Smart Tool, mouse up, drag cutoff frequency to 695, 782, 743
  • Hold down the Command key while mousing for finer contro
Paste Special

Image pasteSpecial</IMG>

  • Multiple Automation Lanes
    • Click on small triangle at lower left corner of track, automation "lane" will appear
    • Click on + or - buttons to add more lanes or remove unwante
Automation Lanes

Image autoLanes</IMG>

  • Select desired parameter in the pulldow
  • Use Edit : Paste Special : To Current Automation Type to paste to other tracks
Plug-In Automation

Image auto1</IMG>

  • Make a tempo change - since track has been set to "Tick Based," automation will follow tempo
  • Note - The "Conductor" (Window Menu : Transport - the blue box) has to be on for tempo events to work

Image conductor</IMG>

  • Click on the "+" sign just to the left of the Tempo rule
Tempo Event at Bar 9

Image tempoChange</IMG>

Air Talkbox Effect: Interesting Vocoder type sounds:

Air Talkbox Effect
Image talkbox</IMG>

Elastic Audio Mangulation of a Sine Wave

By repeatedly shifting a sine wave down in pitch until it is out of the audible range, and then shifting it back up, interesting sounds can result. Making the track tick-based and playing with tempo events allows for varispeed effects.

  • Create a 1 kHz sine wave at -6 dB
  • Enable Elastic Audio - Polyphonic (the tiny "upside-down Y" button
Elastic Audio Polyphonic Mode

Image elastic</IMG>

  • Clip Menu : Elastic Properties Floating Windo
Elastic Audio Properties Floating Window

Image elasticPitch</IMG>

  • Select clip and set Pitch Shift to -24 (Pitch is now down two octaves to 250 Hz)
  • Consolidate with Option + Shift + 3
  • Repeat - Pitch is now 62 Hz
  • Repeat - Pitch is now 16 Hz - Pro Tools will get confused...
  • Pitch up + 24 two more times, we're back to 250 Hz, in theory...
  • Repeat the entire process again...
  • Set track to tick-based
  • Select clip
  • Change Elastic Audio to "Varispeed"
  • Event Menu : Tempo Operations : Linear - set ending tempo to 240, or 60..
Event Menu : Tempo Operations : Linear

Image linearTempoChange</IMG>

  • Try slowing the tempo way down (as in 5 BPM) and then changing the Elastic Audio plug-in to "Rhythmic." Interesting..
Tempo Operations Window

Image linearTempoChange2</IMG>

Elastic Audio Mangulation of a Square Wave

Square waves have - in theory at least - infinitely many odd harmonic overtones. Pitch shifting them up by many octaves pushes the overtones out of the range of the digital system. Pitch shifting them back into range results in a sound with altered harmonics. The Mod Delay plug in can then be applied to create vibrato effects and beyond.

  • Create a 1 kHz square wave at -6dB
  • Enable Elastic Audio - Polyphonic
  • Clip Menu : Elastic Properties Floating Window
  • Select clip and set Pitch to +24 (Pitch is now 4 kHz)
  • Consolidate with Option + Shift + 3
  • Repeat - Pitch is now 16 kHz
  • Consolidate
  • Now reverse the process, shifting the pitch down until you get a sound you like
  • Insert A Mod Delay
Mod Delay Used as a Vibrato

Image vibrato</IMG>

  • Interesting Alteration #1
    • Increase feedback to +/- 50 (or more)
    • Increase Delay Time in small increments (you can type in as little as .1 milliseconds), listen to the difference
    • Play with the low pass filter
  • Interesting Alteration #2
    • Try these settings
Mod Delay Used as an Extreme Vibrato

Image vibrato2</IMG>

  • Use the "Power Claw" trick to automate the Depth control
  • Control Command click on the Depth control to switch to its automation playlist
  • Select the Pencil Triangle Too
Pencil Triangle Tool

Image triTool</IMG>

  • Set the grid to 1 Bar
  • Draw automation with the triangle too
Automation with the Pencil Triangle Tool

Image triAuto</IMG>

  • Try changing the rate (it often interacts with the frequency of the source tone in interesting ways)
  • Put some echo or delay on it..

Elastic Audio Mangulation of a Drum Loop

  • Oasis Chorus 2 Loop - 140 BPM, 4 Bar Loop
  • Identify Beat - set Pro Tools tempo to 14
Identify Beat

Image idbeat</IMG>

  • "Conductor" has to be on
  • Set Elastic Audio plug-in to Monophonic
  • Use TCE Trim tool, stretch loop to 40 Bar
10x Stretch

Image 10xStretch</IMG>

  • Apply excessive compressio
Excessive Compression

Image compress</IMG>

  • Apply Sans Amp distortio
Sans Amp Distortion

Image sansAmp</IMG>

  • Apply Phase Shifte
Phase Shifter

Image phaser</IMG>

  • Sounds a bit "buzzy" - let's tame it with some eq
Low Pass Filter, -18 dB/Octave at 2.45 kHz

Image lpf</IMG>

  • Let's smooth it out even more with another compressor, this time with less agressive settings

Image comp2</IMG>

  • Add some delay to make it sound more ethereal
  • Click on a send selector, use "New Track" again, create an Aux track called "Ambience"
  • A new send window will appear Option click the fader to set it to zero, or adjust it by ear
Create an Ambience Send and Return
Image ambSend</IMG>
  • Put a Mod Delay on the return track
  • I like to make the left and right a little different - note the settings
Image modDelay</IMG>

  • And just for good measure, a little Plate reverb to smooth things out a bit more:

Image verb</IMG>

  • The plug-ins plus the send and return look like this
Plug-in Chain, Send and Return

Image plugChain</IMG>

The original drum loop:

The processed drum loop: