DRIVER

PROBLEM TO BE SOLVED: To reduce bass noise by suppressing amplification of noise.SOLUTION: A driver 10 includes an amplifier 11 for supplying an input signal Si, while amplifying, to a speaker 1, a current detector 12 for outputting a detection signal V1, according to a drive current IR flowing to a speaker unit 4, a drive control section 13 for making a signal, based on the detection signal V1, positive feedback to the input side of the amplifier 11 so as to generate an equivalent negative impedance thus controlling the drive state of the speaker unit 4, and an adjustment section 14 for adjusting the transmission gain (β) when making a signal, based on the detection signal V1, positive feedback to the amplifier 11 based on the input signal Si.SELECTED DRAWING: Figure 1 【課題】ノイズの増幅を抑制して低音ノイズを低減する。【解決手段】駆動装置１０は、入力信号Ｓｉを増幅してスピーカー１に供給するアンプ１１と、スピーカーユニット４に流れる駆動電流ＩＲに応じた検出信号Ｖ１を出力する電流検出部１２と、検出信号Ｖ１に基づく信号をアンプ１１の入力側に正帰還して等価的に負性インピーダンスを発生させてスピーカーユニット４の駆動状態を制御する駆動制御部１３と、入力信号Ｓｉに基づいて、検出信号Ｖ１に基づく信号をアンプ１１に正帰還させる際の伝達利得（β）を調整する調整部１４とを備える構成である。【選択図】図１