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4 After the Lips: Acoustic Resonances and Radiation
Fig. 4.43 Calculated horn function and internal pressure distributions for the first four acoustic
modes of a Bessel horn approximation to a trombone bell. (a) Bore profiles for a Bessel horn
trombone bell approximation (solid line) and a Conn 8H trombone bell section (dashed line). (b)
Horn function calculated for the Bessel horn trombone bell approximation. Values of k 2 for the
first four resonant modes are marked by horizontal lines. (c) Pressure distributions for resonant
modes in the Bessel horn trombone bell approximation. Mode 1: black lines. Mode 2: red lines.
Mode 3: green lines. Mode 4: magenta lines. The bell exit plane (at x = 1.13 m) is marked by a
continuous vertical dashed line (Color figure online)