Finite Impulse Response Filter Design - Digital Signal Processing: Fundamentals and Applications - page 296

7.25. A digital crossover can be designed as shown in Figure 7.45 .

Consider the following audio specifications:
Sampling rate ¼ 44,100 Hz

Crossover frequency ¼ 2,000 Hz

Transition band range ¼ 1,600 Hz

Passband ripple ¼ 0.1 dB

Stopband attenuation ¼ 50 dB

Filter type ¼ FIR

Determine the following for each filter in Figure 7.45 :
a. window function
b. filter length
c. cutoff frequency

Use MALAB to design both filters and plot frequency responses for both filters.
7.12.1 Computer Problems with MATLAB

Use the MATLAB programs provided in Section 7.11 to design the following FIR filters.
7.26. Design a 41-tap lowpass FIR filter whose cutoff frequency is 1,600 Hz using the following
window functions. Assume that the sampling frequency is 8,000 Hz.
a. rectangular window function
b. triangular window function
c. Hanning window function
d. Hamming window function
e. Blackman window function
List the FIR filter coefficients and plot the frequency responses for each case.

Gain_H

Highpass filter Tweeter:

The crossover passes
high frequencies

yH(n)

Digital
audio x(n)

Lowpass filter Gain_L Woofer:

The crossover passes
low frequencies

yL(n)

FIGURE 7.45

Two-band crossover in Problem 7.25.