Dome + Horn + Sphere
File: Dome - Horn + Sphere.axi
See also examples: Cone+Horn+Sphere
This example demonstrates an advanced setup and comparison to measurement.
Setup and Field-Plots
A 50mm convex dome drives a conical horn of length 120mm and mouth-diameter of 235mm. In front of the horn is placed a rigid sphere of diameter 195mm. The distance between the bottom of the sphere and the horn-mouth is 100mm.
The above field pressure contours are taken at approx 100, 1k, 2k and 5kHz. The SPL-range is 50dB for all plots. Interesting to observe is the build-up of modal patterns and the "Fresnel-Beam" at the top of the sphere.
Comparison with Measurements
The SPL measurements and simulations are taken at points on an arc of 300mm radius centered in the middle of the horn-mouth.
At low-frequencies the level drops because of the finite size of the baffle, which is approx. W = 950mm by H = 1150mm. The finite baffle also causes some diffraction-ripples in the range below 1kHz. The damping of the measurement chamber is fairly good above 500Hz. Below 500Hz reflections are to be expected.