说明：  用奇阶互补法设计两带滤波器组(高、低通互补)，进而实现四带滤波器组；并画出其频响。滤波器设计参数为：Fp＝1.7KHz, Fr＝2.3KHz, Fs＝8KHz, Armin≥70dB。
(Odd order complementary method to design two-band filter bank (high-and low-pass complementary), so as to realize the four-band filter group draw the frequency response. The filter design parameters: Fp = 1.7KHz, Fr = 2.3KHz, Fs = 8KHz, Armin ≥ 70dB.)