Mitsuhiko Serikawa

Apparatus and method for controlling tone quality

A digital signal represents a desired amplitude frequency characteristic. A desired transmission characteristic is derived from the desired amplitude frequency characteristic. A sound signal is processed in accordance with the desired transmission characteristic. The processed sound signal is converted by a speaker into corresponding sound. The process of the sound signal corrects and compensates for the original sound pressure frequency characteristic of the speaker and thereby actualizes the desired amplitude frequency characteristic.

The multi-channel sound field control system in a multi-purpose hall

Abstract In this study, the effect of a digital sound field control system (DSFC) with loudspeakers arranged three-dimensionally in a multi-purpose hall is discussed. A method is presented of making the tap data set up in the DSFC, based on simulated reflection patterns using the usual ray tracing method. Each reflection is ultimately divided into two vectors which make phantom images when they are reproduced by two loudspeakers, while the three-dimensional information of reflection pattern is comparatively preserved. The advantage of this method is that reflections can be produced using small sized hardware. One application of DSFC based on this method is shown in an existing shoebox-type multi-purpose hall, where one side of the wall is flat and hard, while another wall facing it is covered with diffusers, and the reflection patterns of this hall are very unique. The target reflection patterns can be obtained in this specific hall by using the DSFC.