Sound Particles SkyDust 3D

Sound Particles have placed 3D audio at the heart of their new soft synth.

Sound Particles produce some very effective immersive sound processing software, and in their latest venture they’ve applied that technology to a synthesizer — which is apparently a world first. The synth itself uses a set of eight multi‑waveform oscillators that can either be combined in layers for analogue‑style subtractive synthesis or used individually as frequency modulation (FM) sources to modulate other oscillators. The oscillators are then fed into a mixer and each layer has its own filter, modulation and envelope settings. There are various options for further modifying the oscillator waveforms, and also onboard effects, arpeggiators and sequencers. Sound Particles have arranged the GUI using tabbed sections to make accessing all these features very straightforward.

The unusual part is that the surround panning technology that underpins most of the existing Sound Particles plug‑ins has been integrated into the synth, so that surround pan position becomes a modulation destination. In other words, panning can be controlled by all the usual modulation sources such as envelopes, LFOs and sequencers, as well as having access to a set of preset trajectories. Each of the oscillator sources feeding into the mixer can have its own panning regime, so what you end up with is a multi‑layered sound where the various layers each move independently. The output format can be selected to suit your monitor system from mono or stereo to a long list of almost 30 discrete surround formats up to 13.1 (and compatible with Dolby Atmos), binaural or Ambisonics, so there’s scope for creating sounds that work on headphones as well as on surround speaker systems. Apparently the synth uses ACN/SN3D (otherwise known as AmbiX), so to use Ambisonics SkyDust 3D just needs to be placed on a DAW track that supports it. There are several binaural format options from which to choose, and further sub‑choices for each of those formats.

If fully immersive synth sounds don’t fit into your workflow, then you can buy the less costly SkyDust Stereo, which has all the same features other than the output format options, which in that version are limited to stereo or binaural.

The Oscillator screen provides a choice of waveforms, modulation and envelope shaping.

A large selection of patch presets is available and these can be viewed by category. There’s also a Dice button to make random settings, with a menu that lets you lock specific aspects such as pitch, timbre or spatial settings so they won’t change as you try different random settings. Presets are also available for arpeggiator sequences and 3D movement, so you don’t have to do deep‑dive editing until you are ready.

Views

The various views are selected via tabs at the top of the page, set out as Main, Oscillator, Filter, FM, Pitch, Spatial, Arpeggiator, Effects, Extras and Matrix. The Main page shows the factory presets as well as a graphical overview of the surround space, in which the different oscillator layers are represented by coloured dots. In addition to the main patch presets there are also presets for Arp, Pitch and Spatial settings, as well as a setting in the header bar for the output format. The oscillators offer a number of waveforms, adding noise and rectified waves to the usual analogue shapes. These waves may then be further modified by various folding, crushing and time‑manipulation treatments. Pitch can be controlled by octaves, transposition and detuning. Each oscillator has its own envelope generator that can be selected from a simple AR type right up to a full DAHDSR (ADSR with added delay and hold). LFO modulation can be tempo sync’ed and also has a choice of waveforms.

Moving to the filter page brings up a comprehensive analogue filter type of arrangement with all the usual filter types and a choice of slopes, keyboard mapping, modulation velocity mapping and detailed envelope control. The FM page includes a matrix display as well as a block diagram of the oscillator connections, and it is possible to use any combination of ‘straight’ and frequency‑modulated oscillators. Modulation oscillators can be routed to more than one carrier oscillator if required. The FM ratios can be adjusted along with detune, feedback and modulation amount. The Pitch page also offers envelope and multi‑waveform LFO modulation with the addition of randomisation amount for specific parameters.

The FM screen is where the oscillators’ routing can be viewed. Note that the Mixer view is open at the bottom of the screen.

So far we’re in reasonably familiar territory, but things change in the Spatial section, where movement in the 3D space can be controlled by LFO, sequencer, envelope or movement modifiers. These last are based on a selection of preset movement patches with definable start and end positions. Adjustment is also available for Azimuth, Elevation and Depth. Separate movement paths and rates can be set for note release phases.

The arpeggiator has its own page and offers a choice of patterns, sync options, mono/poly note modes, scale quantise, number of steps and so on. Further choice is available in the Effects section where you’ll find bit‑crushers, delays, distortion, EQ and reverb. An Extras page provides eight further envelope generators and eight more LFOs that can be assigned to any parameter, while the Matrix page allows for setting up MIDI control and arranging the source and destination for the various modifier options. A Settings section accessed via the familiar cog icon accesses MIDI settings, polyphony, pitch‑bend range, master tuning and so on, but you can also import an HRTF (Head Related Transfer Function) file in SOFA (Spatially Oriented Format for Acoustics ) file format, in addition to choosing from the binaural presets available.

Bottom Panel

At the bottom left of the page are more tabs for Keys, Mixer, Macros, Pads and Spatial. In the Keys page you can activate Arp, Legato, Pitch and Spatial functions as well as seeing a smaller version of the surround space at the right‑hand side. Mixer blends the various oscillator outputs and offers solo and mute buttons, rotary controls for four effects, and a meter fader accompanied by an even smaller view of the 3D space.

Macros allows multiple parameters to be assigned to the four Macro knobs, while Pads brings up two X/Y pads where the two axes can be assigned to various parameters. A snap mode allows the X/Y position to return to its original location when the mouse or trackpad is released. Spatial provides a number of different views of the voice movements along with a master multi‑channel meter to show the levels of the voices being fed to the various surround channels.

Performance

Leaving aside the spatial aspects for a moment, the synth itself offers a combination of analogue and FM voices, which makes for a great deal of flexibility. Not being sample‑based, you don’t get the option of calling up specific instruments, but then that isn’t the point of this type of synthesis. It is all about being creative, and there’s plenty of scope for layering classic analogue sounds with tinkly or raspy FM sounds. There’s a large range of presets to get you started, searchable by sound type, and here you’ll find pads, basses, synth strings, synth brass and things that go boing in the night. Adjusting the mixer offers a quick and simple way to tweak the presets, but it is also pretty straightforward to edit the envelopes and filters for each voice.

Setting up your own FM routing is a bit more challenging as there’s a bit of a learning curve involved in getting FM to sound like anything other than collapsing scaffolding or a psycho dentist, but there’s plenty of useful stuff in the presets section that you can use.

We’re already very familiar with stereo panning and other types of modulation that create a sense of movement, and SkyDust just brings all of that into the 3D world.

Space

The spatial aspect of this synth might seem like a gimmick but for certain types of music, including film work, it can be quite captivating as the voice layers that make up the various sounds move around independently of each other. We’re already very familiar with stereo panning and other types of modulation that create a sense of movement, and SkyDust just brings all of that into the 3D world. As you might expect, such complexity takes up more CPU overhead the a typical analogue synth emulation, but given what’s going on, I still found it to be very efficient.

The Spatial view offers various views and control options for the 3D panning.

While having the various voices buzzing around your head like flies might sound as though it would be distracting, in practice it generally feels more subtle, especially when playing polyphonically as the various movements blend to create a kind of 3D ensemble effect, with the various harmonics moving in space. Sometimes, when using faster movement settings, it can feel as though you have three or four Leslie speakers inside you head, but overall I found the effects to be musically enjoyable, and as the 3D aspects are fully editable, you don’t have to go overboard with the surround effect if you don’t want to. The spatial effects sound most effective on loudspeaker systems, which for most end users means a visit to the cinema, but the binaural options can also sound impressive over headphones while still sounding perfectly acceptable over loudspeakers, so that’s the way I’d probably use the instrument in conventional music production.