(a)–(d) Far-field projected directivity balloons from the present work. (e)–(h) Played trumpet directivity balloons derived from recordings available from Weinzierl et al. [74] plotted over the original 32 sampling positions and (i)–(l) interpolated via an N = 4 spherical harmonic expansion to the same 2521 sampling positions as the present work. (a), (e), and (i): 277 Hz (D♭4). (b), (f), and (j): 738 Hz (G♭5). (c), (g), and (k): 1314 Hz (E6). (d), (h), and (l): 1869 Hz (B♭6).