Patent ID: 6763113
Filing Date: 2004-07-13
Classification: H04R

Abstract:
A loudspeaker driving circuit comprising:volume adjusting means for adjusting an output level of an audio signal supplied to a loudspeaker of a television receiver; a loudness control circuit having variable frequency characteristics corresponding to an adjusted state of said volume adjusting means for emphasizing a signal level of low-frequency components of the audio signal adjusted in level by the volume adjusting means; a level detecting variable resistor operating in conjunction with the volume adjusting means and producing an output representing an adjusted state of said volume adjusting means; a high-pass filter for reducing low-frequency components of the audio signal and being selectively inserted in a signal path of the audio signal following the loudness control circuit; bypass switch means for bypassing the high-pass filter in the signal path of the audio signal; a switching control circuit including a comparator responsive to the output of the level detecting variable resistor, wherein the switching control circuit controls the bypass switch means to bypass the high-pass filter when the output of the level detecting variable resistor is below a threshold level and controls the bypass switch means to insert the high-pass filter when the output of the level detecting variable resistor is above the threshold level; and a loudspeaker driver circuit for supplying the loudspeaker of the television receiver with the audio signal.