user manual
TA-500
The Aspect Polyhorn™ Concept
The patented Polyhorn™ design effectively solves the problem of the tendency for exponential horns to beam with increasing frequency. Dividing the multi-cellular horn into multiple tapered waveguides guarantees that the path length of each micro-horn is equal from the surface of the driver diaphragm to the horn mouth, and ensures that all frequencies from all parts of the diaphragm arrive at the horn mouth together. This provides the wavefront with uniformity of phase. A further benefit of the Polyhorn™ geometry is that the sound wave does not suffer from edge-diffraction effects which have a tendency to confuse the directionality of the sound source.
Each cabinet in an array of Aspect loudspeakers contribute to the generation of a single, cohesive, and more or less continuous wavefront without noticeable comb-filtering effects. In addition, the Polyhorn™ design offers the possibility of locating the acoustic centre well behind the motor system and even the enclosure. The wavefront radii can now be arranged to coincide with the array curvature, forming a single virtual point source.
Because of the Polyhorn™ design’s sharp cut-off, its array angle can in practice be taken as being the same as the dispersion angle.
Fig 1. Conventional HF horns produce destructive interference
Fig 2. Poyhorn™ creates smoothly curved and phase-coherent wavefront
TA-500 user manual Page 8