Abstract
In this paper is given theoretical considerations for providing a sound source which is flat in frequency characteritic and can radiate large sound power all over the range of audio frequency. A constant sound pressure source can be obtained by the following method. Many small diaphragms are arrayed in concentric circles on a rigid sphere. Outer diaphragms are caused to vibrate in the same phase in the low frequency range, and the vibration is moved inward with an increase of frequency, while the total volume acceleration is kept constant. It is made possible to obtain a nearly ideal constant sound pressure source by using the active dividing networks which keep the total volume acceleration constant, delay networks connected in cascade, and an equalizing network. Some results of experiments on the sound field characteristics of vibrating diaphragms on a sphere are also shown.
