Matlab can be employed to design the required filters and then Simulink can be usedto implement the graphic equalizer in real time. Most commercial equalizers use either1/3 octave or 2/3 octave bandpass filters but to keep this from becoming too large we willemploy one octave bandpass filters. Following are the design specifications for theequalizer:1. Employing Matlab, design 5 different bandpass filters with center frequencies of63 Hz, 250 Hz, 1000 Hz, 4000 Hz, and 16000 Hz. These center frequenciescorrespond to the ISO (International Standards Organization) standard for graphicequalizer center frequencies.2. The bandwidth of each filter is the frequency difference ∆f = f2 – f1, where f1 andf2 correspond to the frequencies where the gain is 3 dB less than the maximumgain at the center frequency. It also is necessary to choose f1 and f2 such that thecenter frequency, fc, is equal to the geometric mean of f1 and f2, i.e. fc = (f1f2)1/2.We also have to choose the bandwidth of each filter so that we get a flat frequencyresponse when all filter gains are equal and added together.3. You can use Butterworth filters; however you are free to choose the order of thefilters. The Matlab help file for the Butterworth filter is the following:[B,A] = butter(N,Wn) designs an Nth order lowpass digital Butterworth filter and returns the filtercoefficients in length N+1 vectors B (numerator) and A (denominator). The coefficients are listedin descending powers of z. The cutoff frequency Wn must be 0.0 < Wn < 1.0, with 1.0 correspondingto half the sample rate.If Wn is a two- element vector, Wn = [W1 W2], butter returns an order 2N bandpass filter withpassband W1 < W < W2.[B,A] = butter(N,Wn,'high') designs a highpassfilter. [B,A] = butter(N,Wn,'low') designs a lowpassfilter.[B,A] = butter(N,Wn,'stop') is a bandstop filter if Wn = [W1 W2]