A simple digital method is described that can produce an undistorted acoustic sine wave using an amplifier and loudspeaker having considerable intrinsic distortion, a common situation at low frequencies and high power. The method involves, first, using a pure sine wave as the input and measuring the distortion products. An iterative procedure then progressively adds harmonics with appropriate amplitude and phase to cancel any distortion products. The method is illustrated by producing a pure 52 Hz sine wave at 107 dB sound pressure level with harmonic distortion reduced over the audible range to >65 dB below the fundamental.

1.
J. -M.
Chen
,
J.
Smith
, and
J.
Wolfe
, “
The effect of nearby timpani strokes on horn playing
,”
J. Acoust. Soc. Am.
135
,
472
478
(
2014
).
2.
F. X. Y.
Gao
and
M.
Snelgrove
, “
Adaptive linearization of a loudspeaker
,” in
Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP-91
(
1991
), pp.
3589
3592
.
3.
W. J.
Klippel
, “
Adaptive nonlinear control of loudspeaker systems
,”
J. Audio Eng. Soc.
46
,
939
954
(
1998
).
4.
K.
Lashkari
, “
A novel Volterra-Wiener model for equalization of loudspeaker distortions
,” in
Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP-06
(
2006
), Vol. 5, pp.
V
117
V
120
.
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