# Tapped horn

> How to model a tapped horn subwoofer in 00 Simulator: front entry and rear tap positions, the throat chamber, the Horn Editor, diagnostics, folding and Hornresp export.

Source: https://simulator.00aud.io/docs/horns/tapped-horn

Both faces of the diaphragm tap into the same horn at two points, and the horn has one mouth. Tapped horns give a lot of low bass from a cabinet that is small for the band it covers, which makes them a common subwoofer choice.

_Figure: The tapped horn drawn by the simulator's schematic, with its chambers, paths and outputs._

The tapped horn example, with a B&C 21SW152. Front entry position: 14 % · 35 cm. Drawn by the simulator when this page was built.

## How it connects

The path starts at a closed end. The front of the cone enters at the front entry position and the back of the cone at the rear tap position, further along.

There is no box behind the cone: the path itself loads both faces, so its length and the two entry positions set where the output peaks and where it cancels.

## When to use it

### Good for

- High-output subwoofers in a compact, foldable cabinet.
- Drivers with a strong motor, a low Qts and plenty of excursion.

### Watch for

- Below the working band the horn stops loading the cone and excursion climbs. Use a high-pass filter and check excursion at the power you plan to use.
- Above the working band the response has deep notches and peaks. A subwoofer’s low-pass filter normally sits below them.

## What you set

Set the enclosure type to **Horn**, then choose **Tapped** under **Horn type**, in the enclosure panel or in the **Horn Editor**’s path bar.

### In the horn card

The horn card in the enclosure panel lists each path as a row: click one to open that path in the **Horn Editor**. The card also sets:

| Control | What it sets |
| --- | --- |
| **Throat chamber** | **Volume**, and its **Cross-section** under **Advanced**, for a front coupling chamber. |

### In the Horn Editor

The path itself is set on the **Horn Editor** tile. Drag it in the drawing, or switch the tile to **Table** to type each value:

| Control | What it sets |
| --- | --- |
| **Main horn** | The area at the closed end, then up to eight spans, each with a **Flare**, a **Length** and the **Area** where it ends. |
| Driver marker | Where the front of the cone enters: the front entry position, in cm from the closed end toward the mouth. |
| Rear tap marker | The same, for the back of the cone. |

The driver and rear-tap markers can both be dragged along the path. The drawing starts at the closed end. [How the Horn Editor works](https://simulator.00aud.io/docs/horns/editor).

## What the front entry position does

Only the front entry moves. The working band barely changes, and the simulator reports the same −3 dB point for all three. What moves is the region above the band: with the entry furthest from the closed end, the first deep notch falls much closer to the top of the band.

_Figure: Simulated SPL of the tapped horn for 3 values of front entry position: 6 % · 15 cm, 14 % · 35 cm, 30 % · 75 cm._

The tapped horn example. Only the front entry position changes between the lines. Simulated when this page was built.

Front entry position, SPL: B&C 21SW152, Half Space · 1.0 m · 100 W.

| Front entry position | −3 dB |
| --- | --- |
| 6 % · 15 cm | 37 Hz |
| 14 % · 35 cm (the design drawn above) | 37 Hz |
| 30 % · 75 cm | 37 Hz |

## Diagnostics and stuffing

The one output is the Main mouth. Locations include the closed end, both entry points and the span ends. When the throat chamber has both a volume and a cross-section, it shows as Front coupling. [Reading the horn diagnostics](https://simulator.00aud.io/docs/horns/diagnostics).

Any span of the horn can be stuffed, including the closed section before the front entry. [How stuffing works](https://simulator.00aud.io/docs/horns/stuffing).

## Folding and Hornresp

- **Folding:** Available. The **Fold** tile keeps the closed end capped and leaves clearance for the cone near it. Its **Front tap** and **Rear tap** chips show where the driver lands on the folded path, and its **Hornresp** tab gives TH or TH1 values.
- **Hornresp export · TH or TH1:** The front tap must be at S2 and the rear tap at S3 or S4; otherwise the export stops with that reason. Taps at either end of the path are refused. The two faces need opposite polarities.
- **Checked against Hornresp:** 22 native Hornresp cases of this type are re-simulated in the regression tests. 19 of 19 agreement checks meet their tolerances, and 3 more track stuffing-model differences without claiming agreement.

[Folding a horn into a cabinet](https://simulator.00aud.io/docs/horns/folding) · [Exporting to Hornresp](https://simulator.00aud.io/docs/horns/hornresp)

## Try it

_Interactive walkthrough in the page: the simulator's own tiles running a short demo._

To keep going, open the example in the simulator. It opens with this type already set up, so you can change it and watch the graphs follow.

- [Open the tapped horn example](https://simulator.00aud.io/app?template=tapped-horn)

## Ask your AI

**Ask your AI**

With 00 Simulator connected to Claude, ChatGPT or another MCP client, your assistant runs this same solver on your own workspaces.

> Using 00 Simulator, open my tapped horn and try moving the front entry position to 10 %, 14 % and 25 %. Simulate each at 100 W without saving, then show me SPL and excursion and tell me which keeps the cleanest response above the band.