When first unboxing Reaktor 5 back in 2000-and-something I was blown away by the capabilities of these other-worldly synths, drum machines, granular sample destroying effects and sequencers, but it was some of the generative tools that really captured my imagination.
Whilst I’m still not quite au fait with the monstrously complex Skrewell, SpaceDrone is a neat tidy little unit capable of some beautiful sounds without too much work. Most interestingly it’s actually a quite simple machine when you peek at what’s behind the curtain.
SpaceDrone is a self-playing ensemble, creating sounds ranging from lush, ethereal ambient soundscapes, not dissimilar to the weird and wonderful noises captured by NASA of other planets and moons, cold industrial tones, insect-like chattering and sounds that wouldn’t be out of place in a Andrei Tarkovsky film.
This is what Reaktor’s blurb has to say about it:
SpaceDrone generates atmospheric pads which range from light rain or howling wind noises to deep and uncanny space sounds. Technically, the instrument is based on 96 parallel voices spread across the frequency spectrum. Each voice consists of a noise generator; the signal’s amplitude is shaped by an envelope, its frequency content gets modified by a bandpass filter, and finally it gets positioned in the stereo field.
To simplify this a little, SpaceDrone is a 96 (yes, ninety-six!) voice synthesiser. It generates white noise tones that are pseudo-randomly band-pass filtered, given an amplitude envelope shape and spread across the panoramic spectrum. Let’s investigate the front panel.
The Front Panel
There are two graphic displays to get out of the way first. They display the volume (in white, on the left) and the position within the stereo spectrum (blue, on the right) of the 96 voices.
They’re quite pretty but don’t really contribute to the functionality of the ensemble so I wont be dealing with them any further than this. We’re also just focusing on the ‘A’ view, which is the sound generation bit, while the ‘B’ view is a reverb unit.
In green I’ve highlighted the remaining controls. Starting off with the top left and middle left we have two knobs for Attack and Decay. These control our amplitude envelope of our voices. When you look at what’s going on, we actually have an ADR (attack, decay and release) envelope with the Decay knob controlling both decay and release, although sonically it wont make huge amounts of difference.
The Pitch dial is a bipolar control of the amount of modulation our amplitude envelope has on the sounds perceived pitch. As it is bipolar it means when at 12’o’clock the dial is having no effect, and moving it clockwise and counter-clockwise will increase the modulation. It’s most easily heard when cranked to extremes, adjusting the Attack and Release settings you can hear the pitch and timbres produced.
The Density, Rnd and Dynamic knobs are all related to the Geiger macro which we’ll delve into properly later. Density sets the rate at which our amplitude envelope is retriggered, Rnd sets the randomness of the retriggering and Dynamic sets the range of our potential amplitudes. When fully clockwise we have a wider dynamic range of sounds and when fully counter-clockwise all voices are at a more constant maximum volume.
The Res dial relates to the resonance or Q of our band-pass filter. Turning it up to maximum can produce more tonal sounds, akin to a resonator. Here’s a simple patch with the resonance being slowly turned up:
To finish the top row of dials off we have control for the rate of panning of the voices and an associated Rnd dial, which controls the amount of random panning.
The Damp is a simple way to control the frequency content of the sound. Whilst it sounds a bit like a low-pass filter or low-shelf EQ it’s actually a bit more complicated than that. Turn it counter-clockwise to open up the higher frequencies and clockwise to attenuate them.
The numeric readouts in the middle control the perceived pitches of our patch. The Fundamental actually controls our band-pass filter (more on this later). Rapidly adjusting this will give something between a filter sweep and running up a chromatic scale.
Offset is a little harder to understand – this ascends the harmonics associated with the fundamental. Harmonics are integer multiples of our frequency and are a naturally occurring phenomena. Increasing this will give you a similar sound to the Fundamental but less “musical”. Here’s the Fundamental and Offset being increased and then decreased one at a time.
Lastly we have Speed and Amt (amount), both of which control a Slow Random LFO module; this affects the incoming pitch to the band-pass filter. Set the Amt at 0 to more clearly hear the fundamental frequency and increase it to diffuse it. Speed sets the rate of the LFO.
There’s quite a lot to swallow there, so don’t worry if you didn’t fully understand all of it, some of the best sounds from this can come through simple experimentation. Looking at the structure and signal path of the module actually cleared a few things up for me.
Under the Hood
Let’s examine the architecture of SpacedDrone by going into edit mode and delving into the instrument.
This may look a little fiddly, but I can assure you it’s a hell of a lot simpler and easier-on-the-eye than some other Reaktor ensembles.
Firstly you should notice that there are four macros (highlighted in pinky/red), two named Display, the Geiger macro and one titled Space.
Macros are like a folders containing other modules and core cells within Reaktor. I’m going to ignore the two Display macros as they’re solely concerned with the visual side to SpaceDrone, which I don’t want to focus on.
In addition I’m going to ignore the Space macro right at the end of the signal path – this is just the reverb unit. Disabling it really roughens the patch up (not in an always pleasing way).
Much like all synths, the signal path of SpaceDrone is actually quite simple. Yes there’s loads of modulation from all-sorts of pseudo random sources but here are the nuts and bolts:
This isn’t the prettiest diagram I’ve ever made, and this is an oversimplification, but we can expand on it. Let’s start with the green route. This is how most subtractive synthesisers work.
We have some sort of tone generation (in this case a white noise oscillator), a filter, and then an output or amp. SpaceDrone’s output is slightly more advanced, allowing panning within a stereo spectrum and it has it’s own dedicated reverb. Aside from that it’s fairly standard.
In Orange we have the ADR (attack, decay, release) envelope, which controls both our amplitude and filter cutoff. This is triggered by our Geiger macro, which we’ll deal with in more depth later. In Purple/red is a Slow Random LFO module controlling the rate of triangle wave LFO, which in turn determines the pan position of our voices.
Of course SpaceDrone is not as simple as it first seems and there’s a lot of maths going on that I’m not going to go into in this write up. Whilst SpaceDrone is not technically a granular synthesiser, it has a similar sonic effect to one. Each voice is assigned a filter frequency cutoff and position within a stereo field, not dissimilar to the grains in the context of a granular synth.
At the heart of this all this is a simple 2-pole band-pass filter. The In and Res inputs are relatively simple. The In takes the output of the Noise module and Res(onance) has a simple knob on the front panel. However the P (for Pitch) input is slightly more complex, and this is largely what gives SpaceDrone its unique, musical sound.
As mentioned previously the Fundamental and Offset determine each voice’s pitch and harmonic; this effect is not dissimilar to the Aetherizer, which users of Absynth may be familiar with. It’s a granular effect based on short delays, pitch-shifting and a musical sounding filter that is capable of creating very tonal cloud-like swarms of sound.