AxiDriver - Examples - Dome + Horn + Sphere

R&D Team |  AxiDriver-Home |  Examples |  Contact

Dome + Horn + Sphere

Dome+Horn+Sphere-Picture 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

Dome+Horn+Sphere-Field 100Hz Dome+Horn+Sphere-Field 1kHz

Dome+Horn+Sphere-Field 2kHz Dome+Horn+Sphere-Field 5kHz

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

Dome+Horn+Sphere-300mm Contour Measured Dome+Horn+Sphere-300mm Contour Simul

Dome+Horn+Sphere-300mm 0 deg Dome+Horn+Sphere-300mm 10 deg Dome+Horn+Sphere-300mm 20 deg Dome+Horn+Sphere-300mm 30 deg Dome+Horn+Sphere-300mm 40 deg Dome+Horn+Sphere-300mm 50 deg Dome+Horn+Sphere-300mm 60 deg Dome+Horn+Sphere-300mm 70 deg Dome+Horn+Sphere-300mm 80 deg

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.