Viridian, i was referring to the F as a point source simply because all of the sound references back to ONE point of origin i.e. a single driver. As to what is classified as a "point source" in terms of radiation pattern, that may be completely different. However, one does need to point out that your elimination of the F as a point source based on the comments that you made would rule out ANY speaker that used any type of a baffle, a grill that caused diffraction, etc... due to the distortions ( peaks and nulls ) that they would generate. As was discussed here previously, a radiating sphere suspended in space is the only ideal "point source". Sean
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