Enchanting Instruments 73 - Electronic Sound Source Mechanism 13: Double Pendulum

In recent years, we’ve seen very few new synthesis methods emerge. Amid this trend, I’d like to introduce a unique sound synthesis approach that debuted in 2020.

The Double Pendulum

A double pendulum consists of a second pendulum attached to the end of a standard one. Its motion is unpredictable and chaotic. The simulated motion in the video demonstrates just how complex its movements can be.

This principle has been applied to a software synthesizer called Pendulate, a unique sound source unlike any other. Developer Dan Gillespie stated that his curiosity about what kind of sounds could be produced by converting double pendulum motion into audio was the inspiration for its creation.

Newfangled Audio Pendulate (Free, available via Eventide Audio)

The architecture of Pendulate is simple: a double pendulum oscillator (generator), a wavefolder, and a low-pass gate.

What sets it apart from traditional synthesizers is the proprietary oscillator labeled ‘Double Pendulum’, which the official documentation refers to as a ‘generator’. This section leverages the double pendulum principle, creating a completely novel oscillator unlike anything we’ve seen before. Once you grasp how it behaves, you should be able to tweak it to some degree.

How to Use It

The normally round knobs are square-shaped, giving the interface a quirky appearance. When getting to know a synthesizer like this, it’s best to start by producing the simplest waveform possible. Manually reset the parameters to the most basic state, as shown below.

Next, focus solely on the behavior of this unique oscillator. Set the parameters to their default positions as shown below. Set INTERVAL to ‘Uni’, and leave the others at 0%. Since SUB1 and SUB2 are for reinforcing lower frequencies, keep them at 0 for this demonstration. The key parameters to explore are AMOUNT, SHAPE, ANIMATE, and INTERVAL.

With these settings, the oscilloscope will display a pure sine wave. It appears that the double pendulum behavior is applied to this base signal.

An animation displayed in the background adds a visual accent to the user interface. The sine wave is represented as a perfect circle. As modulation is applied, distortion and movement start to appear. Just watching the animation is an enjoyable experience in itself.

CHAOS AMOUNT: When set to 0, turning any other knobs will have no effect. As you increase the value, the harmonics defined by the INTERVAL setting begin to emerge. When AMOUNT exceeds 50%, the harmonic level surpasses the fundamental tone. Since it’s labeled ‘CHAOS’, it seems that the behavior of the double pendulum is embedded in this parameter.

CHAOS SHAPE: This is another CHAOS parameter, which aggressively adds harmonics. As you increase it, the sound can evolve into noise, as shown in the video below. At certain high levels, the INTERVAL setting is disregarded, resulting in integer-based harmonics. It felt intuitive to treat this as a kind of feedback control.

ANIMATE: Setting this to anything other than 0 causes the harmonic levels to fluctuate, resulting in dynamic, moving sounds. Increasing the value speeds up the motion, which is visually reflected in the animation.

INTERVAL: This parameter adjusts pitch in semitone steps. Selecting harmonics such as 5th, Oct, or 2Oct provides more stable results. When SHAPE is increased, this parameter is ignored.

Grasping how these four parameters interact is key to mastering the double pendulum generator. The idea is to define the range using the two chaos parameters and control the movement with ANIMATE. Lowering SHAPE and using INTERVAL produces fewer harmonics but allows for creating unique, mysterious tones. If harmonics are insufficient, the wave folder can easily compensate for that. Additionally, each parameter can be modulated by LFOs or envelopes, offering a high level of flexibility.

Impressions of Pendulate

Pendulate is surprisingly user-friendly and reminiscent of an analog synthesizer. Initially, I assumed it would behave more like an FM synth and prepared myself for a chaotic experience. However, as long as you understand the behavior of each parameter, there’s little risk of getting lost in complexity. Given that it utilizes the unpredictable nature of a double pendulum, direct control could have easily become impossible. Instead, the design seems deliberately structured to make control manageable. The principle of the double pendulum is reflected in the dynamic waveforms, creating effects that are far from simple repetition and offer unique results.

While I focused primarily on the oscillator, I must mention the power of the wave folder. Few synthesizers incorporate a wave folder, making this a standout feature. The oscillator was tamer than expected, but in contrast, the wave folder exhibited intense and unruly behavior.

There is also a paid polyphonic version, which includes additional effects, offering a more practical and versatile setup.

■ New Pendulate Chaotic Synth Plug-in by Newfangled Audio (Presets Demo)

The Challenges of New Sound Sources

Personally, I welcome the emergence of various new sound sources. However, since most of the sounds currently in demand have already been realized, it has become increasingly difficult to highlight the differences offered by new synthesis methods. Inevitably, many new sounds end up resembling something we’ve heard before. Conversely, creating sounds that are completely unfamiliar often fails to attract attention, as most users tend to seek sounds that are already recognizable. In the world of synthesizers, subtractive synthesis is the standard approach, and many users can quickly grasp and utilize it. When it comes to entirely new types of sound sources, users must often learn sound design from scratch, which can feel cumbersome. Ultimately, without a compelling and distinctive appeal, it seems challenging for new entrants to achieve success. Efforts to digitally replicate analog sounds have matured considerably, and technologies for synthesizing human voices continue to advance. As a result, the landscape may become increasingly complex, defying simple categorization under the term ‘sound sources’.

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