A full 3D acoustic simulation of the horn you designed in the Horn Design Tool. Rather than
approximating the mouth as a radiating aperture, it solves the actual wave equation on a 3D
grid — so diffraction around the horn, and its true horizontal and vertical directivity,
come out of the physics rather than an assumed pattern.
Calculation Frequency Range
Method
One broadband pulse is simulated and Fourier-transformed, so a single run yields every
frequency in the range at once.
Counter-intuitively, a narrower range costs more time, not less. Frequency
resolution is 1/T — to separate features 10 Hz apart you need 0.1 s of recorded
sound. Zooming in demands a longer recording. Lowering the bottom bound is expensive for
the same reason; raising the top bound is expensive because it forces a finer grid.
Calculation Angle Range
Method
Virtual microphones on an arc around the horn, in both the horizontal and vertical planes.
This is the biggest single lever on run time. Up to ±90° the simulation only needs space
in front of the horn; going beyond that requires modelling the space behind it too, which
substantially enlarges the grid.
Directivity Map
Level relative to on-axis, angle against frequency. Deep red is 0 dB (loudest);
blue is 30 dB down. Same colour scale as the Horn Design Tool.
Axes are always the full 20 Hz–20 kHz and ±180°, so what you calculated appears
as a band within the whole space and two runs can be compared directly. Anything outside
the calculated range is left blank — never extrapolated.
What this does not model
The horn is simulated free-standing, with the driver's rear sealed as a real compression
driver's is — there is no cabinet, baffle or room. Results below the stated far-field
limit are indicative only. This is an experimental research tool: validate any final
design against a real measurement.
