| 摘要 |
PURPOSE:To prevent reduction of audible sense related to the Fletcher-Munson characteristic at a small sound volume by providing a sound volume tracking frequency characteristic change means changing the frequency characteristic in response to the sound volume adjustment volume so as to correct automatically the frequency characteristic at the small sound volume. CONSTITUTION:In maximizing sound volume by turning clockwise the knob of a sound volume adjusting volume 7, a slider 7c and an end point terminal 7b are allowed to contact and a slider 6c of a frequency characteristic changing volume 6 is allowed to contact also with an end point terminal 6b. Thus, only a sound signal through an amplifier 10 is given to the slider 7b and the frequency characteristic is unchanged. In turning counterclockwise the sound volume adjusting volume 7, the sound volume is decreased and also the slider 6c of the frequency characteristic changing volume 6 is slid in the direction of a start point terminal 6a, only a high frequency component through a bypass filter 2 is amplified and added via a resistor R1, and the high frequency components of the frequency characteristic are emphasized. Thus, the reduction in the audible sense related to the Fletcher-Munson characteristic is corrected. |
