Abstract:
A method to measure and describe horn drivers and horns as independent parts was investigated. It is shown, that the well-known two-port representation can be adopted for the system characterization considering certain assumptions and limitations. The horn driver is represented as a two-port whereas the horn is characterized by its acoustical input impedance and due to its three-dimensional sound radiation by it?s on-axis transfer function and a relative directivity. With both sets of parameters the electrical input impedance, the transfer function and the directivity of any horn driver - horn combination can be synthesized by a software tool without the need to measure the real combination. This method speeds up procedures of either loudspeaker system design or design and optimization of new horn drivers and horns respectively. Besides general purpose measuring techniques some specialized measuring equipment is required like an impedance tube fitting to the horn throat and an anechoic chamber to record the directivity of the horn. Finally, all possible combinations of seven horn drivers and eleven horns have been studied to show the reliability of the method.