Spatial effects for DJs
Two kinds of effect: a DJ’s stereo effects translated into movement, and whole-field effects that only a 3D system can do. Neither has a published reference mapping; everything here is derived (from motion perception and the MJ playbook) or an idea waiting for a design. Tags: R = rests on research, G = a guess to test, sim = checked in the movement lab’s simulation.
Stereo DJ effects, translated
A DJM’s Beat FX are set in note values (delay and echo 1/16–16 beats; filter, flanger, phaser cycles 1/16–64 beats). A DJ thinks in those values; a 3D effect should too.
Stereo effect |
In 3D |
Rate |
Tag |
|---|---|---|---|
Auto-pan L↔R |
a step between two opposite points (a fast glide at most) |
½–2 beats per side |
G; step > glide (short glides fall under the ear’s integration time) — R, sim |
Auto-pan circle |
rotation |
1 lap per 1–4 bars; 1 lap per beat only as a swirl |
R |
Filter sweep |
sweep the moving band’s FREQ while it orbits: the band “climbs” (higher is heard higher) |
4–16 bars |
R (Lee 2015) + G |
Echo throw |
throw the delay return to the side opposite the source and let it drift back |
over 1–2 bars, delay ¼–1 bar |
G; needs the delay on its own movable path |
Riser |
climb in elevation, double the rotation every 4 bars, high FREQ |
8–16 bars |
R (elevation needs HF) + G |
Drop |
snap the band to the front, or freeze it, on the one |
1 beat |
G; the “stop and restart on the one” result supports it (sim) |
In the simulation every effect cost a little attention when used as a routine: effects are accents, not the main course.
Whole-field effects on a deck’s B-format (ideas, 2026-10-30)
StemDeck’s decks deliver their stems as a 3rd-order Ambisonics field (B-format). On that field, the whole room can move rather than one source — the effect no stereo setup has. The maintainer: “note the fx. we will need them.” Not designed or scheduled; each would be an IEM plug-in in the engine, per deck input.
Effect |
Tool (IEM suite) |
What the room hears |
CPU |
|---|---|---|---|
Spin |
SceneRotator |
the whole deck turns around the room, beat-synced (e.g. one turn per bar), or tilts overhead; hold to speed up, release to land home on the downbeat |
almost none |
Tunnel / zoom |
AmbisonicWarp (ToolBox) |
the field pulled together towards one direction during the build, snapping open to the full room on the drop: a spatial riser |
low |
Explode |
GranularEncoder |
one stem (hats, a vocal chop) scattered as grains over all speakers, then pulled back |
medium |
Throw / freeze |
FdnReverb (ambisonic) |
a 3D echo-out: send a stem, freeze, the tail stands everywhere while the beat runs on; pairs with the delay |
medium |
Directional ducking |
DirectionalCompressor |
sidechain pumping from one direction only: the kick pushes the pads backwards |
low–medium |
Doppler room |
RoomEncoder |
a stem as a source in a virtual room with reflections and Doppler: a fast orbit gets a real swoosh |
high, per source |
Start with spin and tunnel: cheap, whole-field, and the hardest hit (build → tunnel, drop → spin).
How they are operated (DJ view, not decided)
One pad per effect, momentary: hold = on, release = back. There is no undo in front of a room.
Beat-quantised start and end (next downbeat or bar), with a “now” override — the same pairing as quantised transport with an instant variant.
One knob per effect for intensity (spin speed, tunnel width, grain spread).
Per deck, wherever the deck runs.
Movement and stems: how much of a stem goes into 3D
A stem at rest is steady. An action raises the stem’s 3D to full over its first beat and lowers it over its last (the effective 3D is the deck’s 3d × the action’s envelope). A separate per-stem 3D knob was tried and dropped (2026-10-29): with stems, the action is the gesture.