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GOREBANG — Audio and effects label.

Stairwell

An impossible tall-space reverb — shafts, silos and stairwells far bigger than physics allows.

Buy — $39 AUD  →

A reverb plugin that renders a made-up vertical space from its geometry rather than from an impulse response. Tall, narrow, acoustically plausible, and much larger than anything you could actually build. A GOREBANG effect on the 4B Pedal Platform.

The interface. ROOM, SURFACES and SPACE over the geometry view; OUTPUT bottom-right; the EXPERIMENTAL section behind the amber toggle.
One imaginary geometry, three layers — early reflections, the vertical slap, and a diffuse late field with a coupled second volume behind it.

The idea

Most big reverbs are either a recording of a real room or a bank of delays tuned until they sound like one. Stairwell is neither. It carries a small model of an imaginary space — a shaft, a silo, a cathedral stairwell — and works out what that space would do to a sound: how long each reflection takes to come back, how much quieter and darker it is for the trip, where it lands in the stereo field.

The space is deliberately impossible. Height goes to 500 metres in an enclosure a few metres wide. It stays acoustically coherent the whole way up, so it reads as a real place you could never actually stand in.

The principle is model the cause, not the effect. Doppler, distance darkening, the way an echo smears as a room grows — none of those are effects bolted on afterwards. They fall out of one number, the length of a path, changing over time.

How it works

Three layers, all derived from the same geometry:

  • Early reflections. Explicit image-source taps — the distinct first slap off that wall — fed through a four-stage diffuser into a dense stereo cluster.
  • The vertical echo. The round trip up the shaft and back, its delay set directly by Height. Move Height and this is the part that audibly Dopplers.
  • The late field. An eight-line feedback delay network for the diffuse tail, its decay set by Material, with slow sub-audio modulation so it never turns metallic. Behind it sits a second, larger, one-directional volume — the vault above the landings — that fills while a note plays and then holds a long swelling tail, the fast-then-slow decay real caverns have.

The geometry maths runs at control rate, not per sample, so a 500-metre room costs about the same as a small one.

The controls

  • ROOM — Height (2–500 m), Width and Depth (2–60 m). The proportions of the space.
  • SURFACES — Material (bare concrete to fully absorptive), Diffusion, and the Reflections level.
  • SPACE — Distance (how far across the room you're standing), Coupling (how open the aperture to that second volume is), and Geometry Response — an always-on slow drift on every path length, so even a static preset breathes and detunes slightly. Turn it down for rigid concrete; turn it up and the room feels alive.
  • OUTPUT — Dry/Wet and Bypass.

Experimental

Behind an amber toggle: Warp, Collapse, Runaway, Fracture. Four reactive violations of the one equation the rest of the plugin obeys — delay equals path length divided by the speed of sound. Warp retunes the medium itself. Collapse pitch-dives the room on every attack. Runaway pushes the vertical echo past unity into a controllable building resonance. Fracture splits each echo into a hard-panned beating cluster.

The section is inert until it's armed — with the toggle off, the engine is bit-identical to the plain reverb. Runaway's regeneration is gated to input, so it rings out with a note but can't howl from silence.

Presets and formats

Around thirteen factory presets so far — Cathedral Shaft, Missile Silo, Impossible Tower, Concrete Stairwell, Elevator Void, Falling — plus a handful that show off the experimental section (Dive Bomb, Screaming Shaft).

Built on the 4B Pedal Platform DSP core — the same JUCE-free core that runs Hot Fuzz and targets 4B Core hardware — with a thin JUCE layer on top for the plugin. Ships as VST3, AU and a standalone app; universal binary on macOS, VST3 on Windows.

Status

Early beta (v0.1.0). The DSP is solid and in testers' hands; the release process is not done. Right now that means no code signing or notarisation, no installer — a manual file copy — a short preset list, and no manual beyond the tester notes. Those are the next jobs, not open questions.