A horn including a substantially flat coupling flange defining a coupling
flange plane, a substantially planar mouth defining a mouth plane, an
elongated throat extending between the coupling flange and the mouth, a
transducer for generating a sonic output operationally connected to the
coupling flange, and a major axis extending through the elongated throat.
The coupling flange plane and the mouth plane are nonparallel and define
a horn angle. The major axis connects the coupling flange and the mouth
and the elongated throat is characterized by a substantially steadily
increasing sectional area along the major axis from the
transducer-connecting end to the mouth connecting end.