Abstract
There are many interesting and practical problems in nonlinear effects of a sound field. In particular, progressive waves of finite-amplitude cannot be propagated without a change of waveform, which is a wellknown phenomenon and the subject of many reports. For a quantitative estimation of the waveform distortion, it is generally assumed that the wave at a source is purely sinusoidal or that the initial sinusoidal wave is radiated, and note only the progressive distortion by excluding other distortions mainly due to non-sinusoidal motion of the diaphragm of the source. In the present paper, we have relaxed that condition so as to investigate thoroughly the relation between the motion of the diaphragm and the received signal. This paper concerns the cancellation of second harmonic sound pressure of the progressive distortion. Theoretically, it is possible to cancel out the harmonic at some receiving point by adding a small signal to the driving current and determining the amplitude and phase of the small current appropriately. In the method, however, the assumption as an independent propagation of the fundamental and second harmonic waves is necessary, i. e. , this argument is valid only so long as the distortion is not so remarkable. Initially the theory is discussed in terms of finite-amplitude plane wave. Secondly, the analysis is extended to an arbitrary radiation field and examined by experimentation using a horn loudspeaker. Agreement between these results is satisfactory with respect to the driving current-form. Although this study is now at a basic stage in investigations on boundary problems in finite-amplitude sound fields, it can be applied to the construction of a no wave distortion field.
