Using this widget, you’re able to mix together single sine waves (partials) into more complex sounds that you can play and build. It’s like having your very own little synthesiser to tinker with and at the same time learn about how different waveforms is built up from their component frequencies.
Simply click onscreen controls with your mouse or use your computer keyboard to play naturaly. By pressing one of the keys on the bottom on-screen keyboard you will hear that sound playing right there in your browser. The letters correspond to keys found on the computer keyboard; each has a label naming the note it plays.
How to Use the Sound Widget
Above the keys is some shift buttons that alter octave range of the keyboard. These buttons simply move the whole keyboard scale up or down by octaves, allowing for exploration into various pitch ranges. If you feel like you have accidentally got a key stuck then press the panic button to release all notes immediately.
Centered on the interface is a bank of vertical faders that control level of an individual harmonic partial (beginning with the fundamental frequency and ascending up to the sixteenth harmonic). Simply pull the fader upwards to include it in your mix, or pull it downwards to remove that particular partial. Clicking the number button beneath each fader reverses phase of that corresponding partial too, which changes the wave of just that frequency, altering the waveform slightly but not drastically shifting the perceived pitch.
If you want some quick starting points, use the preset buttons along the top left to load preset combinations of these partials. In my experience, triangle, square, and sawtooth waves are the ones available.
You can also adjust the envelope settings controlling the tone of your sound. Attack is how rapidly it increase from silence; decay is how fast it decreases back to the sustain value. Sustain is the volume level at which the tone will play while the key remains depressed. Release is the duration the sound takes to die away once the key is released. There’s also a brightness decay control which steadily lowers the level of higher harmonic frequencies throughout the length of the note. This contributes some realism to the sound as real struck or plucked instruments naturaly tend to lose their higher harmonics over time.
The sustain toggle switch specifies whether held notes continue playing until a key is released or they fade out based off the envelope parameters. The addition of other partials increase the volume; however, there is an option to switch on the normalise mode that retains the overall volume. By default when playing back multiple harmonics, the volume becomes very loud without this mode. Normalising keeps the volume in check.
There is a volume slider that determines the overall volume of the master output. You can use this to determine how loud the finished mix will be before coming out of your speakers. Finally, the pitch slider adjusts the fundamental frequency of your complete stack, shifting the pitch of every partial to match. This could of been useful if you are exploring how the harmonic structure varies at different pitches or if you are simply playing along to a song.
What I like about the display options is that you can choose between displaying the resulting harmonic spectrum or the actual waveform itself. In the waveform view, you can see the actual form of the sound wave and get an idea of how removing or adding certain partials will alter the curve. In the spectrum view, each partial is shown as a bar, making it easy to see which frequencies are present and their volumes. It’s also really handy if you want to learn more about how some waveforms, such as a square wave, are constructed using only odd-numbered harmonics.
To further immerse yourself in the process, try the fullscreen button. It expands the widget across your whole screen, removing distractions and providing extra space to view the waveform and faders more easily. There’s also a help panel where you can get some quick references to tips and controls when you’re not sure what something does. If you want to put your understanding of harmonics and your ear to the test, there is a match the timbre game mode as well. It puts a hidden target sound out, then asks you to mix it back using the faders with feedback on how close your mix comes to the original.
Without picking up the mouse at all, you also have an easy method of playing and controlling the widget from your computer keyboard. Simply press any of the letter keys A, J to play notes on the on-screen keyboard, using them to play some melodies with ease. If you want to move into a higher or lower pitch, simply hit the X and Z keys to raise or lower the octave in real time. Quickly change between wave shapes by pressing number keys 1-8 which instantly loads that preset. Hit the space bar to turn your sound on and off, and toggle between the spectrum view and waveform view with the I key.
Now experiment with the phase inversion buttons. This will alter the polarity of some of the partials and you’ll be able to hear the difference this makes to the sound. The pitch is unchanged but the waveform shape becomes completely changed as you can see on the waveform display. Inverting the odd harmonics can result in another textural difference whereas inverting the even harmonics can produce a fluty, hollow tone. These small differences show that amplitude and phase relationship both shape a sound.
Explore the envelope settings to discover how these change the nature of your sound. Shortening attack times and lengthening decays can produce a pluck string type of sound, whereas slower attacks and higher sustain values resemble an organ or swelling pad. Envelopes that emulate percussion work well when paired with the brightness decay setting. This setting will gradually roll away the harsh high-end frequencies, giving a more natural feel to what are essentially synthetic sounds.
When attempting to re-create any given waveform, use the spectrum view to help guide your ear. For example, if it’s a square wave, then concentrate on raising the odd-numbered faders while leaving even numbered ones at zero. To create a sawtooth wave, simply raise up all the faders but taper them in terms of height so the higher partials are more quiet. It visually connects the abstract idea of harmonics with what you’re hearing. Alternatively, try creating your own custom wave from scratch by just raising a couple of the partials and listening to how each frequency interacts with one another.
For beginners: Select a preset and gently adjust the faders to get an idea of what parts of the sound stem from which partials. Play some kind of simple melody on your computer keyboard as you adjust the envelope; it’s fun to hear how the sound changes in response. Adjust the brightness decay to make your patches more realistic sounding. Because this widget has been designed to explore, don’t be afraid to throw the faders around and listen for interesting blends/clashes. When you’re confident with what the widgets does, test your skills and learn more about harmonic structure through the game mode.