Horns · Guide

Fold a horn into a cabinet

A horn that works on the graph still has to fit in a box. The Fold tile packs the horn path into a cabinet you can build and sits beside your graphs, where every frequency graph draws the folded horn as a dashed line. You see whether the fold can be built and what it does to the sound at the same time.

Side sectionSerpentine · 5 runs · 530 mm wide
Path length
2,500 mmtarget 2,500 mm · +0.0 %
Air volume
409 Ltarget 409 L · −11.4 %
The tapped horn example, folded when this page was built: a serpentine fold with 5 runs in a cabinet 530 mm wide.

Which horns fold

Folding works on front-loaded, back-loaded, tapped and offset-driver horns, which each have one path. Stubbed, compound, multiple-entry and Paraflex horns need junction, branch or entry layouts the fold does not handle yet. For those, the button is disabled and the Fold tile says so.

Open it

Choose Fold into cabinet in the Horn Editor tile’s title bar, where it reads Fold on narrow screens. The first time, it saves a suggested fold, a three-lane serpentine, fits a box to it and adds the Fold tile beside your graphs. You can also add the Fold tile from the graph picker and choose Fold this horn. From then on every change is saved with the enclosure, and undo takes it back.

Choose the fold

Auto folds the path in a pattern you pick. Choose it from Fold pattern and set its count; the fit tries every variant of that pattern, with the throat on a wall or sliding and the mouth on the floor or the lid, and never switches pattern by itself.

Serpentine
Lanes that double back on themselves, 2 to 6 lanes.
Spiral
Turns the same way at every bend, 3 to 6 laps.
Wrapped serpentine
A serpentine whose last turns carry on around the cabinet, 3 to 5 rows.
Columns
A serpentine of upright columns, 2 to 5 columns.
Straight
One run, no folds.

Draw lets you lay the path yourself. Tap cells from the closed end to the front column, or use the arrow keys and Backspace. Tapping one step past the edge grows the grid, tapping a path cell cuts the path back there, and dragging a bend flips it to the other corner. The fold solves as soon as the path reaches the front.

Set the cabinet

The cabinet popover holds the outside Height, Depth and Width and the Material. Typing a dimension locks it: that is the one your room decides. The unlocked dimensions are solved for the smallest box that passes every check, and Fit box runs that fit again. When no box inside the locks passes, the fit returns the buildable fold closest to your horn.

In the drawing you can drag the driver along its board, and its taps follow. Drag a board across itself to hold it there. Shift keeps it level or plumb, and a double-click lets it follow the horn again.

Read the checks

The tile shows one chip per check. A passing chip shows a tick, a warning keeps its number, and an error names what is wrong. Open a chip for its details and the fixes that apply, such as changing one dimension, re-centring the driver or moving your front tap to the smallest distance a board allows. Nothing blocks saving or simulating.

ChipWhat it checks
LengthThe folded path against your design. It warns from 0.5 % off and fails beyond 3 %.
Front tap, Rear tap or Driver entryWhere the driver actually sits on the folded path, against the positions you set.
DriverWhether the driver fits where the fold puts it, clears the boards and the shell, leaves the cone room to move, and how much its motor blocks the passage.
ChamberThe throat or rear chamber the fold leaves, against the volume you set.
ShapeHow far the runs give way from your areas, the narrowest passage, and boards pinned against a wall.
MouthThe folded mouth area against your design. It warns beyond 15 %.
Can’t buildGeometry that cannot be made: overlapping passages, boards ending in open space, the mouth off the front panel. The passage is drawn red.

Boards you hold show a Held chip, which also releases them.

The folded line on your graphs

Every frequency graph, apart from the horn diagnostic graphs, draws the horn this fold builds as a dashed line in the enclosure’s colour: the folded spans, with the taps where the driver really sits. Its pill in the legend and in the tile hides it. It is left out when the fold cannot be built, when the horn already matches the fold, and when the horn is stuffed or damped, because stuffing cannot be carried onto the folded passage yet.

Use this fold writes the folded spans and taps into your horn, so the simulation follows the fold. It locks the box and holds every board, and the pill then reads Matches horn. Let the fold follow the horn on the Held chip releases it, and one undo puts everything back.

Full screen

Full screen opens the whole editor: the inputs on the left, the side section or a 3D cutaway in the middle, and Profile, Cut list, Hornresp and Response tabs on the right.

  • Profile plots area against distance from the throat for your design, the folded passage and the simulator’s equivalent of it.
  • Cut list lists the boards. Hornresp gives the folded passage in Hornresp’s terms, with Copy Hornresp values. Hornresp export.
  • Fork as enclosure adds a copy of the enclosure that simulates the fold beside your design. It uses the taps the fold achieves when it places the driver, and your target taps otherwise, and says which in the copy’s name. It needs a fold without errors and a horn without damping.
  • Export saves the whole geometry as JSON. It is not a fabrication drawing.
  • Boundary Lab downloads a mesh and project for a coupled FEM and BEM solve in Boundary Lab, once the fold has no geometry errors.
Path length
Measured through the arc of each bend rather than into its corner, which matches measured horns more closely than the plain centreline.
The driver
An editable estimate sized from the driver you chose. The B&C 18DS115, which has a measured model, uses its real frame, cutout, depth and magnet and is drawn as itself.
What it reports
Tapped and offset-driver horns report the taps the fold achieves. Front-loaded horns report their throat and rear chambers, and back-loaded horns their throat chamber.
Dead space
Every cell the path does not use, with its volume. Front- and back-loaded horns open the throat into it as a chamber.

Limits

  • Folds are side sections: boards span the full internal width, with no folding out of that plane.
  • Bends are not modelled as losses or scattering, and driver obstruction is reported but not simulated.
  • Chamber volumes and tap positions are geometric results. Check the folded line or a forked copy before you build.

Ask your AI

Hand it to your AI

With 00 Simulator connected to Claude, ChatGPT or another MCP client, your assistant runs this same solver on your own workspaces. Copy the prompt and paste it into a chat.

Using 00 Simulator, fold my tapped horn into a cabinet no more than 600 mm deep and 900 mm high. Compare the alternative folds it finds, simulate the best one beside my design, and tell me what folding costs in response before I save anything.
Claude
In a chat, open the + menu, go to Connectors and switch 00 Simulator on.
ChatGPT
In a chat, open the + menu, choose Developer mode and select 00 Simulator.
Claude Code
Once the server is added, paste it into any session.
Not connected yet? See the setup steps