Example 1: In this example, noise is applied to the equalizer as the input signal. Oscilloscope channels 1 and 2 display the filter input and output signal respectively. The spectrum analyzer displays the output spectrum. The equalizer frequency sliders are set to create an ideal band-pass filter with the frequency range from 250 to 500 Hz. The filter has a power gain of 15 dB in the pass-band and attenuates the signal by 15 dB outside the band thus giving a difference of 30 dB between the passband and other frequencies.
The power spectrum of the filtered signal spectrum clearly shows the filtering in the frequency range of interest. In time domain, the signal is far less complex than the input signal, due to the fact that the filtered signal is composed of only four harmonics.
Example 2: In this example, the input is a square pulse train.
