DSP Lab Studio: Windowed FIR Equalizer & Audio Restoration

Covers Exp 2 (Sinc), Exp 3 (MyConv), Exp 4 (3.4kHz Tone Restoration), Exp 7/8 (DTFT/Freqz), Exp 9 (FFT), Exp 10 (Gibbs & Windows)

24IC302P - Digital Signal Processing Lab

1. Signal Source Exp 2 & 4

Status: Ready (Click Play Demo or upload orig.wav)

2. FIR Filter Design & Gibbs Exp 10

h[n] = w[n] · Σ G_k · h_ideal,k[n] (Linear Phase Type-I FIR)

3. 5-Band FIR Equalizer Exp 10 (LP/BP/HP)

LPF <250Hz 0.0 dB
BPF 1 250-900 0.0 dB
BPF 2 0.9-2.5k 0.0 dB
BPF 3 2.5-6k 0.0 dB
HPF >6kHz 0.0 dB

4. Audio Restoration Exp 3 & 4

Cascaded via Exp 3 MyConv: h_total[n] = MyConv(h_EQ[n], h_Notch[n])

FIR Frequency Response |H(e^jΩ)| & ∠H(e^jΩ)

Exp 7, 8 & 10 (freqz / DTFT)
Magnitude (dB) Phase (rad) Tone Freq Marker

Real-Time FFT Spectrum |X(k)| vs |Y(k)|

Exp 8 & 9 (4096-pt FFT)
Mixed Input y[n] = x[n] + tone Convolved Output z[n] = h[n]*y[n]

Impulse Response h[n] & Window w[n]

Exp 2 (sinc) & Exp 10 (Windows)
Composite FIR h[n] Window Envelope w[n]

Time-Domain Oscilloscope: Mixed y[n] vs Filtered z[n]

Exp 4 Subplots
Contaminated Signal y[n] Restored/Equalized Signal z[n]