Open Ends
Modulation in general has been front and centre of Bitwig's feature set since version 2's device modulator panels (see Sound On Sound, May 2017), and devices built in The Grid are likely to be heavy on modulation, so I was rather worried that these two modulation worlds might be distinct, or at least different enough to be confusing. But fear not: modulation flows into and out of The Grid's environment without any technical or cognitive hiccoughs (although it only runs in mono at the standard sample rate). For a start, device modulators can drive module parameters inside The Grid just as they can control parameters for any device, and in the same way: 'arm' a modulator, click and drag on a knob or slider, and the modulation path takes effect. (Consider this another kind of 'wireless' patch connection like the pre-cords.) For additional cord-free fun, some Grid modules like envelopes and LFOs have an explicit modulation output, marked by the familiar arrow. Click the arrow to activate, and then click and drag on a destination control to establish the connection. In the screen shot, the step generator is modulating the sustain level of the envelope generator, without any patch cords needed. To treat a general signal in The Grid as a modulator (perhaps after some mathematics or logic processing), there's a dedicated Modulator Out module.
Some Grid modules have output arrows for Bitwig 2-style modulation.Most intriguingly, you can connect a modulation source inside The Grid to a destination outside, like a device parameter in the Grid device's nested chains — and these destinations could even be in third-party VST plug-ins. If you wish to use a Grid device purely as a sophisticated modulation generator, that's fine, though it can only modulate its own sub-devices, so you'd effectively be limited to control of a chain of note and/or audio effects. I spent a happy hour or so connecting various step sequencer generators to various parts of Audio Damage's Discord 4 pitch-shifter, coming up with rhythmic patterns which could charitably be described as unusual.
If you find The Grid a little overwhelming, there are over 200 bundled presets which show off its capabilities whilst providing starting points for your own experimentation. 'Plant Eater' is a versatile bit-crusher effect, 'Grid Arp Synth 1' is an animated analogue bass riff (though the arpeggiation does come from a device in its Note FX chain) and '80s Dystopy' does a reasonable impression of a soft Roland synth pad with some unexpected but dynamic wavefolding — it uses two instances of The Grid, one purely for the chorus effect. 'Dice in Control' is the archetypal modular patch, a plucky rhythmic pattern that jumps between octaves. 'Gripped Beat' is a four-to-the-floor analogue drum pattern, though a bit of experimentation tweaking its sequencers, oscillators and waveshapers produced all manner of techno rhythms. The presets are equipped with a generous complement of macro controls, so even if you don't want to dig into the modular innards, there's plenty of scope for broad timbral changes.
Overall, the editing experience offered by The Grid is clear, neat and intuitive, and integration with the rest of Bitwig is logical and well implemented. If I had to nit-pick, there's only one aspect of Grid editing that I found slightly frustrating: it's a bit too easy to accidentally alter a module parameter when you really just want to select the module or move it around. But that's a minor point: overall, The Grid is a thoroughly impressive effort and really expands the boundaries of what a DAW is capable of.
Supersized Sampler
In Bitwig Studio 2, the Sampler instrument was respectable: it was capable of triggering and optionally looping samples into a multimode filter and envelope, with multisamples supported via zones delimited by note pitch and/or velocity. So far, so conventional, though Bitwig's modulation machinery could be brought to bear to dynamically shift sample start and loop points. But there were a couple of weaknesses: at the voice level, there was no support for loop crossfades, and in multisample mode, zones couldn't crossfade or overlap: a voice would only play a single sample at once. The new Sampler, introduced in Bitwig 2.4 and present in Studio 3, lifts these restrictions.
The new Sampler panel.
A first glance at the new Sampler panel reveals some slight shifting of the furniture — the filter section is now shown to the left of the envelope, for instance — but there are some deeper enhancements. For a start, the filter now supports variable keytracking, as does sample playback pitch itself (before, keytracking to pitch was all or nothing). And there is a loop crossfade parameter to gently smooth the audio at the loop point; for more drastic smoothing, you can set the crossfade to be the entire loop. Without crossfading, the loop section is highlighted as a green block; apply a crossfade, and the green area becomes a colour gradient fading from green to black over the fade area. Crossfading mixes audio from the latter part of the loop with audio leading up to the start of the loop, so loops near the start of the sample are more constrained in terms of crossfade length.
The modulation system that first appeared with Bitwig 2 is really starting to show its power when applied to the Sampler instrument.
There is still a distinction between 'manual' sample parameters such as play start, play stop, loop start, loop end and loop crossfade, which can't be modulated, and what are referred to as offsets: play position, loop position and loop length, which can be dynamically controlled by modulation sources. In Studio 2 these were additional knobs; in Studio 3 they are distinctive coloured sliders, with clear visual feedback. And the modulated parameters are also overlaid dynamically on the waveform display.
Sample looping, with a graduated highlighting of the loop region.
The sliders are part of a new panel area containing, by default, a speed control. This might seem a little superfluous given that there's already a pitch control (best thought of as transposing the sound), but that's only true in the default playback mode (labelled Repitch). In the new playback modes the distinction between pitch and speed becomes significant.
A snowflake icon puts the Sampler into a 'frozen' state, where the usual left-to-right playback is completely disabled: if this were vinyl, it would be the equivalent of stopping the turntable. With freeze active, the speed knob turns into the position control parameter, and you have to move it to hear anything, in the manner of vinyl scratching. Map your MIDI controller here for live scratching, or apply a modulator to sweep the audio. Sampler still operates as an instrument, so you'll have to play notes to hear anything, but this also means that it'll operate polyphonically if you play chords — I'm not aware of many turntables that can do that! With freeze active, keyboard tracking is ignored, as is the pitch setting; position modulation is everything.
Cycles & Grains
Conventional sample playback and this turntable-style scrubbing are both part of the default Repitch mode. Two other modes take Sampler's behaviour into more experimental territory. Cycles decouples the pitch of the sample from the playback speed: as the playback position shifts, individual waveform cycles derived from the sample data play at a pitch determined by incoming notes. Set the playback speed to zero and you have a synthesizer playing whatever single-cycle waveform can be extracted from sample data under the 'play head'. Generally, Cycles works best when the playback position is moving very slowly, or is instantly shifted from one position to another by modulation or MIDI. Sonically, we're in wavetable territory: stay in the same location in the sample, and you have a static timbre (I'm reminded of the classic Korg DW-8000), while a slow position sweep is more reminiscent of a PPG Wave. If the play position is sped up further, the result takes on more of the timbral quality of the original sample as a whole.
In Cycles mode, the sample loop is still active, with the effect of looping a portion of the wavetable (there's no crossfade looping in this mode) and a dedicated formant filter adds some harmonic complexity. Cycles is also a good contender for freezing, if you want to modulate the 'wavetable position' with an LFO or envelope. Overall, I found Cycles to be a decent wavetable source, but rather at the mercy of the original audio; Bitwig could help out here by providing a library of carefully chosen samples that could be used to do high-quality wavetable synthesis. (I discovered, quite by accident, that some of the single-shot samples in the Analog Waves library, mentioned later, work very well as wavetables.)
The final mode is Textures, which performs playback using individual 'grains' of audio from 1 to 300 milliseconds in length. Initially, Textures sounds much like the standard Repitch mode, but the grain-based playback means you can change the playback speed rather than the pitch to get a time-stretching effect. And again, with freeze enabled, you are responsible for positioning the 'play head' where you want it in the sample, via MIDI or modulation control. There's a 'motion' parameter which randomises the playback position for each grain instance, to add variety or richness to the sound. (Motion is not indicated visually in the waveform display, unfortunately.) Unusually for a granular synth, Textures does not appear to play multiple grains at once: to get this effect, you'll have to stack voices. (We look at stacking later.)
The choice of grain size is pretty critical: at the highest settings, you're basically working with a 300-millisecond looping instrument, whilst very short grains get you into the realm of hard sync as audio cycle and grain cycle interfere. Also, the motion parameter is based on grain size, so with long grains you are jumping around in several seconds of audio, while short grains generate various noise textures. Having said that, overall Textures delivered clean and pleasing results with no obvious glitching, though the sound is a little thin unless voices are stacked to add depth.
Stacking Up
To get the most out of Cycles or Textures, you will need to stack voices, and then apply per-voice modulation to vary them. Voice stacking has been a general feature of Bitwig Studio for some time, but it was only with Cycles and Textures that I found myself having to make serious use of it, so it's probably worth taking a look at how it works.
The Device Inspector includes voicing parameters, allowing voice stacking.The Inspector pane for a device provides parameters for the maximum number of voices to allocate to a device, and for the number of voices to play or stack per note. There's also an indication of how many notes are available at once, which is calculated by dividing the first two figures; in practice, you'll probably get more notes than indicated, since voices will be reallocated within stacks. Turn up the voices-per-note value, and voices will be layered, but the sonic effect very much depends on how the voices differ from one another. Bitwig supports polyphonic modulation, so you can randomise parameters by voice (tuning would be a good contender). But there's a set of modulation sources derived purely from the voice stacking: 'stack spread', indicated by a logo of a 3D stack of paper, is a modulation source which provides a value evenly spread across all voices in a note, while the individual 'stack voice' modulators provide constant levels of modulation which can be set on a voice-by-voice basis. For Textures, I found it most useful to stack three or four voices and spread out the playback position and grain size, while my wavetable experiments with Cycles benefited more from a two-voice stack with a slight modulated detuning between them, emulating a chorus effect.
To summarise, Cycles and Textures are similar: they are picking out a small portion of audio to loop, with the audio location dictated by playback speed and/or modulation. In practice, Cycles picks out single cycles of audio to play at the required pitch, while Textures generally works in a longer timeframe to bring out the pitch and features of the original audio. Cycles has the benefit of a formant filter for synthesis; Textures works more in looping territory, with the ability to explore and highlight aspects of the sample. I liked Textures a lot and spent a fair amount of time playing with it, eventually becoming confident that I could rock up to an academic electroacoustic gig and play something convincing. Much as I love wavetable synthesis, I feel that Cycles is a little too sensitive to the quality of the waveform data, and would benefit from some bespoke curated audio assets. Either way, both modes enable Sampler to be transformed into a formidable sound design tool. And clearly, the modulation system that first appeared with Bitwig 2 is really starting to show its power when applied to the Sampler instrument.
