HALO is a spatial delay engine that surrounds a sound with a field of echoes. A single input becomes hundreds of reflections — shaped, set loose, and bloomed into an environment of their own.

Six parameters run along the bottom of the interface — Cluster, Size, Shape, Blur, Mod and Mix. Each is a dot-cluster control whose pattern reflects its current value, and each opens further: an Edit layer of sub-parameters, and a Mod layer that sets any of three modulation sources moving through it. Everything HALO does begins with these six.

HALO runs as a native plugin in AU, VST3 and AAX formats. It loads on any audio channel: as an insert across a single source, or on a send to feed several sources at once.

Mono and stereo inputs are both accepted. A mono source may feed a mono or a stereo channel. The cluster opens into stereo wherever a stereo output is available.

The two placements suit different work. As an insert, Mix balances the field against the source in place, and everything on the Mix Edit tab shapes the wet signal without touching the dry. On a send, set Mix fully wet and treat the return as the field's own channel — several sources feeding one space, carved as one.

Bypassing the plugin fades between the processed and unprocessed signal rather than cutting. The field empties and returns without a click. The fade makes bypass itself performable: switched in time, it breathes the whole space in and out of the mix.

The dotted field is the centre of the plugin, and what it shows depends on where attention is pointed:

The field rewards watching. Brightness is level. Each dot lightens as its echo sounds and fades as it passes — so the eye reads what the ear is hearing: a Reverse contour climbing toward the far edge, a Rhythm figure leaving gaps in the spread, the dots drifting off their grid as Blur takes hold. When a State feels crowded or thin, the field usually says why before the controls do.

The home field is itself a performance surface: dragging across it performs the two XY-assigned parameters without leaving the front page. Assignments are made in the XY Assign tab.

Cluster sets the time window of the field — how far the echoes spread behind the sound.

Narrow, the cluster is a focused knot of repeats pressed against the source. Wide, it is a sprawl of reflections falling away over seconds. The control runs free in milliseconds — from a fraction of a millisecond to two and a half seconds — or locks to the host tempo when Sync is engaged, stepping through divisions from a sixty-fourth note to four bars, with triplet and dotted values between.

Each region of the range has its own character. At the very bottom the echoes fuse, the field stops reading as repeats and starts reading as tone, thickening and colouring the source. Through the middle sits everything a delay is usually asked to be, from slapback to spacious. Toward the top the cluster becomes a landscape: reflections arriving late enough to be their own events, especially with Regen carrying them further still.

While dragging the free control, holding Shift snaps the time to pitch. The readout turns to note names. In the fused region this makes the colouring playable: the window tuned to the key of the piece, the field ringing at a chosen note rather than an arbitrary length.

Toggles the cluster's timing between free milliseconds and tempo-locked divisions. The same switch governs Pre, so the whole front of the field moves between clock time and song time together.

Slews changes to the cluster's timing. Low, a new time snaps into place — audible as a jump, usable as a gesture. High, every change glides, and sweeping Cluster by hand becomes a continuous, tape-like bend. With Regen holding material in the field, the glide is at its most dramatic: the whole cluster bends in pitch as the window stretches beneath it, the classic gesture of a delay played by hand. Smooth is modulatable in its own right.

A pre-delay, the gap between the dry sound and the first echo. Zero holds the field tight against the source; longer settings float it away, leaving the attack clean before the cluster arrives. Free in milliseconds up to two and a half seconds, or in divisions when Sync is engaged.

Feeds the field back into itself. Moderate settings build density and sustain; high settings carry the field far beyond its window, each pass reseeding the next. Above one hundred percent the field no longer decays at all. It grows. Handle with intent.

Size sets the reach of the cluster inside its window — how much of the field the echoes fill.

Low, only the first breath of the window sounds: a short burst hugging the source, however wide Cluster is set. Raised, the echoes reach further and further across the window until, at full Size, the cluster occupies the whole field. Cluster and Size work as a pair, one sets the canvas, the other how much of it is painted.

The pairing is worth using deliberately. Setting Cluster generously and holding Size low leaves headroom: the same wide window can answer with a tight flutter now and a full sprawl later, without the timing itself ever moving. That makes Size the natural handle for dynamics — under an envelope follower it opens the field with the intensity of the playing; under a slow LFO the field breathes; on an XY axis it becomes the reach of the space under one finger.

Size carries no Edit tab. Clicking its label opens its Mod tab directly, and a slow modulation of Size — the field breathing open and closed — is one of the fastest routes to motion in HALO.

Shape sets the amplitude contour of the field, the way level travels across the echoes.

Eight contours are on offer. Clicking the Shape control steps to the next; dragging scrubs through the set. At each change the field previews the new contour before returning to the live cluster.

Sets the taps moving across the stereo field. Eight modes: Off holds the image still; Ping-pong alternates hard left and right; Sweep pans steadily in one direction; Sine sways back and forth; Expand spreads the field from centre to the edges; Circle orbits the image; Bounce rocks side to side with a decaying swing; Wave sends a ripple of position travelling through the cluster.

The modes divide by temperament. Ping-pong and Bounce are rhythmic — placement the ear counts along with, sharpest on short, dry clusters. Sine, Circle and Wave are atmospheric — motion felt more than tracked, made for pads and long fields. Expand is an opening gesture: the image widening as the cluster unfolds, a natural partner to Reverse.

Snaps the field to a pattern — twenty-six figures, A through Z, from steady pulses to broken, syncopated bursts. The control shows each figure as a small constellation of dots as it is chosen, and the field plays the pattern in place of an even spread. With Sync engaged on Cluster, Rhythm turns the field into a tempo-locked phrase.

Blur dissolves the field. One control carries the echoes from discrete repeats to a continuous, regenerating wash.

As Blur rises, everything that keeps an echo separate begins to loosen — position first, then level, then the last traces of pitch — until the cluster stops reading as a delay and starts reading as a space. In the upper reaches the wash takes over entirely: a long tail that feeds on itself, holding and blooming long after the source has gone.

Blur stages usefully in thirds. A little softens. The echoes keep their places but lose their edges, the field sitting further into the mix. The middle is ambience: repeats and wash in balance, delay and reverb at once. High is territory of its own, the source dissolved into a continuous bloom. Blur and Regen both extend the field, from opposite directions — Regen by repeating it, Blur by dissolving it — and the two together are how the longest, deepest States are built.

An on/off switch for the loosening of tap positions inside Blur. On — the default — the echoes drift off-grid as Blur rises, and the field smears. Off, the echoes hold their positions while the wash still builds around them: rhythm intact, air everywhere. The switch matters most with Rhythm patterns, where it decides whether the figure survives the blur.

Rolls the brightness off the wash as it decays. Low, the tail keeps its shimmer to the end. High, each pass through the field grows darker, and the wash sinks into the warmth of the room. Modulatable.

Mod introduces motion into the cluster itself — everything from a subtle chorusing to wide, drastic phase movement.

One control sets the depth. At low settings the echoes detune and thicken gently; pushed, the whole field bends and slurs. The movement is generated by a dedicated engine, exposed in the Edit tab.

Two regions cover most work. Low depth with a slow Rate is the analogue register — the faint instability of tape and old hardware, felt as warmth rather than heard as motion; Drift is the shape made for it. High depth with Wide on is the transformative register: left and right pulling apart, the field chorusing and phasing into something the source never contained. Between the two sits ordinary, beautiful chorus.

The waveform of the movement, chosen from the same thirteen-shape palette as the modulation LFOs — sines and ramps through to shapes drawn from the Slate + Ash instruments.

The speed of the movement, free from a hundredth of a hertz to ten hertz. At the bottom, a drift too slow to follow; at the top, an audible flutter. Modulatable, a modulator on Rate bends the movement's own clock.

Off, the movement is shared by both sides of the image. On, left and right move out of step, and the motion opens into stereo, the field widening with every pass.

Slews the waveform, rounding hard edges. A Square softens toward a sine. A stepped Random becomes a wander. Modulatable.

Mix balances dry against wet — and its Edit tab is a full tone section for the wet signal alone.

The balance is equal-power: the centre of the range holds both signals at full presence, and the extremes hand the output entirely to one side or the other. Nothing in the tone section touches the dry signal — the source passes untouched, and only the field is carved.

The tone section is where the field takes its place in a mix. HP clears the field's low end from under a source that owns it; LP sets distance, the field receding as it darkens; EQ leans the whole space warm or bright in one move. Carving the wet signal this way usually places the field better than lowering Mix — quieter is not the same as further away.

A high-pass filter on the wet field, from twenty hertz to one kilohertz. Clears the low end from a dense wash so the source keeps its weight. Modulatable.

A low-pass filter on the wet field, from five hundred hertz to twenty kilohertz. Pulls the field behind the source, or closes it down to a distant murmur. Modulatable.

Toggles both filters between a gentle slope and a steep one. Off, the filters shade the field; on, they cut it.

A single bipolar tilt for the wet signal, from minus to plus one hundred percent. Below centre the field warms and darkens; above centre it thins and brightens. Zero is flat. One control, the whole tonal lean of the space. Modulatable.

The level of the wet field, from silence to a twelve-decibel lift. The last word on where the space sits against the source. Modulatable — and the classic target for an inverted envelope follower, ducking the field beneath each hit.

EQ and Gain share the final column of the tab. The pair of labels on the right switches which of the two is shown.

Nothing in HALO has to hold still. Every parameter carries a Mod tab, and behind every Mod tab sit three sources.

The Mod tab reads left to right: Source, then Range, then the controls of the chosen source. Source steps through Off, LFO, Seq and Env. Range is the modulated parameter itself, shown with its range arrows — where the movement starts, and how far it reaches. While a source is active, the field draws that source live.

Every parameter keeps its own complete setup, its own LFO, its own step pattern, its own envelope follower, each with their settings held separately. Stepping Source loses nothing: a sequence drawn for a parameter waits behind its LFO, and switching back finds it as it was. Range is the difference between seasoning and transformation. A narrow range animates a setting. The full range replaces it.

With Source off, the field rests behind a veil reading Click to activate modulation. One click engages the LFO and the movement begins.

A low-frequency oscillator with a thirteen-shape palette: Sine, Triangle, Square, Saw Up, Saw Down — then Random, a sample-and-hold scatter; Pluck and Rise, drawn from CHOREOGRAPHS; Pump, a sidechain-style duck; Throb, a swelling pulse; Hang, a swell that holds its peak; Bounce, a decaying oscillation; and Drift, a slow random wander.

Rate runs free from a hundredth of a hertz to twenty hertz, or — with Sync on — locks to divisions from four bars down to a sixty-fourth. Phase offsets the waveform's starting point through a full cycle, letting two modulators of the same rate move in counterpoint.

A step sequencer, drawn by hand. The field becomes the editor: each column is a step, and dragging across the dots sets the values. Steps sets the pattern length — up to twenty-one — and Rate the per-step clock, tempo-synced from eight bars to a hundred-twenty-eighth note. Dir plays the pattern forward, in reverse, or back and forth. Smooth glides between steps, bending a staircase into a curve.

An envelope follower, the incoming signal itself as a modulation source, living and responsive. Gain drives the detector, setting how hard the input pushes the movement: raised, a quiet source speaks fully; lowered, only the loudest moments move the parameter. Rise and Fall set how quickly the movement answers a swell and how slowly it lets go — fast on both and the movement tracks every syllable. A long Fall and each hit leaves a slow subsiding wake, the movement outliving the phrase that made it. Invert flips the response: the parameter falls as the input grows. Inverted onto the wet Gain, the field ducks beneath each hit and blooms back in the gaps — a space that breathes with the performance.

Modulation does not stop at the six front parameters. Within the Edit tabs, the sub-parameters marked modulatable in this manual — Smooth, Pre and Regen under Cluster; Damp under Blur; Rate and Smooth under Mod; HP, LP, EQ and Gain under Mix. Each carry a full Mod tab of their own. Clicking a sub-parameter's label opens it. Routing runs two layers deep, and each parameter keeps its own source, its own settings, its own range.

XY Assign turns the field into a performance pad, two parameters under one hand.

One parameter maps to the X axis, a second to Y. The X and Y labels open a picker listing the assignable set: the front parameters — Cluster, Size, Blur, Mod, Mix — and their modulatable sub-parameters one layer down. Each axis takes a single target, and None leaves an axis empty.

Min and Max set the reach of each axis, the parameter values at the two ends of the drag. Narrow ranges make the pad a fine adjustment; full ranges make it a transformation. A drag across the field then performs both parameters at once, on this tab or directly on the home field.

The pad defers to modulation: an axis whose target has an active Source stands aside, and the drag moves only the axes that are free. A parameter can be performed by hand or by modulator — not both at once — and the pad resumes the moment its target's Source returns to Off.

XY assignments are saved with the State — every factory State arrives with a pairing chosen for it, and User States keep whatever mapping they are saved with.

Four combinations that show the range of the engine. Each is a starting point, not a destination — every control named here has a Mod tab waiting behind it.

Shape to Reverse, Size generous, Blur into its upper third. Each note now swells backwards into a diffuse bloom — the sound arriving before the moment it is played. On sustained material, add a slow Spin (Circle or Sine) and the bloom turns through the image as it builds. Pre gives the swell somewhere to come from; Regen lets one bloom hand into the next.

A wide Cluster, Size high, Blur past halfway with Scatter on, and a slow, deep Mod. Words dissolve into a drifting cloud that follows the voice without repeating it. Carve the field with HP so the cloud floats above the chest of the voice, and pull LP down until it sits behind the consonants. Mix to taste. The effect works as much at fifteen percent as at eighty.

On a drum bus or any rhythmic source: a modest field — Cluster synced, Blur at ambience — then Env on the wet Gain, Invert on, Rise fast, Fall medium. The space ducks beneath each hit and blooms back in the gaps, a room that inhales with the groove. The same trick inverted onto LP instead darkens the field on the hits and lets it glitter in the silences.

Choose a category that matches the mood, then Random — repeatedly. The browser pulls only from within the chosen category, so chance stays on-brief. When a pull lands close, leave the browser, adjust the two XY ranges to taste, and perform the rest on the field. Save often: twenty characters is enough for a name and a date.