Ring Modulation Simulator

Ring modulation is a great little simulator that allows you to multiply two sine waves together and listen to resulting sidebands. Use your computer keyboard to make quick changes, or click on controls with your mouse to play. It also provides an interface that shows what’s going on with the math in real time. This allow you to see just how changing the frequencies will affect sound.

To start you simply choose a carrier frequency with one of the four buttons marked A4, E4, A3 and C3. These serve as anchors for your experiment. Alternatively, hit the corresponding letter (Z, X, C or V) on your computer keyboard which will immediately place the carrier at that frequency. The dial to the left follows the chosen frequency and represent half of the multiplication equation. The second dial is for the modulator, next to the carrier dial. You can drag around ring of this dial, or use the slider. Combining the carrier and modulator results in a pair of sum and difference tones. Sweep the modulator range from 1 Hz to 880 Hz to create new frequencies. These frequencies is shown in the spectrum graph on the right as you turn the dial.

How to Use This Tool

This are the guts of the circuit. These are the controls that power it. The large multiplication symbol sits between the two dials. This is the energize multiplier button which begins audio engine. It can be toggled on and off with the M key on your computer as well. When turned on, the spectrum analyzer and waveform trace will continually update based off these adjustments.

Four sliders below the dials sculpt the output. These include modulation depth, which is how strongly the modulation affect the signal. Wet level is amount of multiplied sound mixed with the carrier sound. Master level is the master volume. The Trace window slider adjust the time scale of the waveform graph. You can zoom out to see a broader picture or zoom in to catch fast transients.

The other set of buttons is labelled Amplitude modulation and Ring product which allow you to toggle between these two circuit. In AM mode, the carrier is present along with addition of the sidebands. In Ring mode, the carrier is removed and the sum and difference sidebands remain alone. To make this selection use 1 on the keyboard for Ring mode and 2 for AM mode. You will then be able to hear the different sound characteristics of both modulations.

Next up is the destination slider for the sidebands. Here, you enter a frequency you want to create as result of your modulation. Click one of the two solve buttons (sum or difference). This set the modulator frequency and calculates it automaticly to reach the desired harmonic interval. It can be activated by pressing the D and S keys on your keyboard too. This is useful if you need to quickly reach certain harmonic intervals.

If you want to listen to something more dramatic, try pressing the “Cross the zero line” button. Here, it slowly sweeps the modulator frequency through the pitch of the carrier. The closer the modulator becomes to the carrier then the closer the difference tone becomes to zero Hertz. What this produces is a warm, warbly sound that fades away towards nothingness. You can hear how the two frequencies interact with each other as they gets closer together.

Look around using the trace window control at the waveform, both at slow and fast speed. A shorter length shows the details of what happens during multiplication. A longer length show the overall shape of the sound. Adjust it while it is playing to see how the visual form relates to what you hear. The spectrum display doesn’t change position on the screen in terms of frequencies. It just changes the height of the bars to show the balance of sounds present.

An in-app help button opens a reference guide with tips for how to use the interface. There is an option to turn off the audio, which resets the state. You can also go into full-screen mode for a bigger view of the controls and graphs. To pause the audio and return to the state prior to pressing play, simply press Escape anytime. This would of help you control your workspace while maintaining your flow.

Experiment with extreme frequency ratios to explore other textural ideas. To get metallic or bell-like sounds, set one of the oscillators a lot higher (or lower) than the other. If you hear something interesting, use the solve functions to work out how it was made. There’s no wrong answer here. It’s made for exploration.

Push the sliders to the extremes, then hear what happens. Begin by selecting a carrier note and push the power button. Slowly turn the modulator knob until you hear the sidebands dissapears. Check the spectrum display to make sure you see the expected frequencies. You can use the visual feedback to get an idea of how the math work behind the sounds.

Have fun experimenting with some of the crazy timbres possible with ring modulation.