Review: Atoms from Baby Audio

Most virtual instruments fall into one of two categories — a “sample library” of real instrument performances or a “synthesizer” of sounds, with (usually) oscillated waveforms morphed and modulated to create sounds no earthly piano, piccolo or pandero cuadrado de Penaparda could achieve.

But a handful of plugins sashay a different path. These are physical modeling instruments, which create sounds not strictly with simple oscillators, but instead by modeling the structure and properties of a real (or imagined) physical system.

Atoms from Baby Audio is a new physical modeling plugin walking the line between traditional synth and sample lib. We’ll break down how it sounds, how much control it provides and what its pretty central display represents. But first, let’s do some modeling.

Synthesis from a different dimension

Let’s Get Physical (But Not That Physical)

It takes a particular sort of expert to fully explain physical modeling. It involves lots of numbers and equations – the kind with little squiggly symbols, you know the ones – and diagrams with vectors and arrows and cosine frappes, probably.

Clearly, I’m not the sort of expert to explain physical modeling. I’m more the sort who can get a stuck lid off a pickle jar – assuming you have two screwdrivers, a set of jump leads and a top-notch first aid kit. So I won’t lead you into the technical weeds of physical modeling – but I will offer a rough description below that I hope is useful.

If you’re not afraid of wading waist-deep into weeds, however, Baby Audio provides a deep-dive video with developer Silvin Willemsen that gets into the nitty and the gritty of Atoms’ take on physical modeling. It’s a must-watch if you plan to get deep into sound design with Atoms, as the video nicely explains how each control affects various aspects of the model or post-model sound. And there’s only one equation, with barely any squiggly bits. Highly recommended.

She Blinded Me… with Springy Masses

The physical models under Atoms’ bonnet are mass-spring systems. Specifically, masses (think weighted balls) connected by springs (or elastic strings), which can be stretched and contracted.

To visualize a simple mass-spring system, consider one of those paddle-ball toys that children enjoyed, back before the internet and tablets and dinosaurs existed. The ball is connected by an elastic band to the centre of the paddle, and the game – such as it is – is to knock the ball with the paddle so it springs out, the band recoils and the ball returns to be thwacked anew.

Now imagine there’s a hole in the centre of the paddle (and never you mind how the string stays attached), so the ball can travel as far below the paddle as above. And instead of a bored child, there’s a fun-seeking robotic arm jangling the toy around, so the ball goes perfectly up and down in a springy line every time.

Then imagine the ball has another 99 balls attached in a line above it, connected with 99 elastic springs. And finally imagine freezing time when this monstrous contraption is in various states of stretchiness or contraction and bowing it like a violin at different spots up and down the line. That’s an over-simple view of the main Atoms model in a layman’s nutshell – but useful to know going in. If you hear “physical model” and think Atoms might sound exactly like a mathematically approximated cello or harp – well, it won’t. But it’s not meant to. It’s meant to sound like a daisy chain of mass-laden springs being bowed, with loads of adjustable parameters. What parameters, you ask? Well…

Nuclear Options

The Atoms interface is attractive and clean, with six main controls huddled around a central visualizer. Four controls affect aspects of the underlying mass-spring model; the final two apply effects after the base sound is generated.

The controls (which also sound like the lineup from the next Suicide Squad movie) are:

• Chaos – introduces nonlinearity (movement side-to-side as well as up-and-down).
• Order – a damping effect, effectively a low-pass filter.
• Force – sets the pressure of the virtual bow on the virtual model.
• Overtones – adjusts the position of the bow up and down the model.
• Drive – distortion; “harmonic clipping with a waveshaping function”.
• Filter – a resonant low-pass filter.

Each control knob is a cluster of options, allowing great freedom for tweaking. An inner colored slider sets precise values, while an outer white slider can be stretched to define a value range. A Motion menu for each knob includes four choices to automate movement within set ranges – Sine, Saw, Drift (i.e., random) and MPE, along with sub-options to set the Rate, Direction and Mode, where applicable. The Filter adds a bonus option to boost Resonance.

Controls along the bottom provide further fine-tuning fare. Users can set the Root octave, the model Profile (basically the number of masses and springs being modeled), Attack and Release, Movement (adjusting the speed and length of bowing), Modulation (the “pickup” position), Vibrato, Space (reverb size and mix) and Output gain.

Finally, the top control strip provides handy utilities, including access to 250 included presets, semi-tamed Randomize and further-narrowed Variation buttons to explore new territory (with an option to Exclude parameters from the perils of random chance), an Undo function, MPE mode, global Tuning, a mono/poly Toggle and more.

Overall, the Atoms interface is attractive and stylish, with clever methods to pack additional options into limited space and plenty of user-focused conveniences like corner-drag to resize, an Eco mode, optional Tooltips and dark and light Theme options.

The visualizer at centre displays a representation of what’s happening within the model as sounds are played. It has some utility – based on the shapes, you can see which model Profile is being used – but mostly it’s eye candy. Albeit very pretty eye candy.

Baby (Audio) Got an Atom Bomb

What does Atoms sound like? Often, like a long springy chain of connected masses being bowed in various ways, because that’s what it’s modeling. Thus, a wide “sweet spot” for Atoms includes sounds that resemble orchestral strings, guitars, basses and pianos.

Despite the emphasis on “bowing”, Atoms is quite good at creating plucky sounds – plucking is really just bowing with a very short attack in a physically-modeled world, evidently – as well as stretching long string-y sounds into atmospheric and evolving soundscapes.

Do the more “instrument-adjacent” settings – presets like “Cello Solo”, “Hurdy Gurdy” and “Shamisen”, for instance – sound like their real-world namesakes? To my ears, no – but I’m not convinced they’re meant to. Despite the specific names, my impression is they’re intended to evoke certain impressions – much as presets like “Cyber Rain”, “Goddess Tendril” or “Darkness Calls” do – without suggesting spot-on imitation.

As a “string-ish” instrument, Atoms has considerable range. It’s straightforward to dial in patches from deep basses to long sustains to glassy plucks – but it’s also easy to push the boundaries. One of my favorite experiments involved tweaking a few parameters on the string machine-like “Cello Solo”, resulting in a pulsing rhythmic growl that would feel at home in an action video game cutscene or slasher flick score.

Atoms Dance

Personally, that’s what I find most intriguing about Atoms. While it’s built on a model, it’s built around movement. The six main controls add life and evolution into Atoms’ output, are easily automated and together comprise a considerable toolset for shaping sounds – including many that don’t sound like bows or springs or paddled balls were remotely involved.

Among the included presets, the “Radioactive” expansion pack highlights the more exploratory side of Atoms, including drones, sound effects and sequences. If you’re concerned a synth based on variations of a single physical model would sound too “samey”, these examples may stretch your notions of Atoms’ range.

There are a few areas in which Atoms could be improved. As slick as the “main” parameter automation is, the “other” controls at bottom don’t get the same treatment. You may be able to automate those within your DAW, but not in the plugin itself.

The “post-model” effects are fairly sparse, as well – drive distortion and a single type of filter. Some other options – ideally automatable – like an equalizer, compressor, delay or more filter choices — would be greatly appreciated.

Finally, a couple of included features could be fleshed out further. The reverb, for instance, is not configurable, save for size and mix; different spaces and options would be very interesting. Additional configuration options for the MPE mode/aftertouch, randomization range and model “profiles” would also be handy.

In fairness, Atoms isn’t currently intended as an uber-tweakable knee-deep-in-numbers physical modeling playground. The supported model Profiles are tested and hand-picked, the randomization parameters limited to ear-safe ranges and some bits under the bonnet are perhaps meant to stay there, unmucked with.

Despite a name that suggests microscopic-level, hands-dirty model wrangling (and possibly squiggly equations!), Atoms is actually more of a physical model showcase, providing access to the friendlier sorts of output its models create, but not the raw unchecked range of possibilities. It’s a certain philosophy and a certain way of producing sounds – but if you’re in the market for a capable source of string-like synthesis, a user-friendly entrée into physical modeling or a unique motion-focused playground for producing pulses and pads, Atoms might be for you.

By Baby Audio Atoms from our partner Plugin Boutique

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