You can achieve a unit step input using a square wave from the function generator. (Think of this as applying step functions periodically in time.) You can omit the op amp from your filters, and use only the RC or RLC portions.
Try to relate the "duration" of the step response of each filter to the associated "cutoff frequency" in the frequency response. Include a brief discussion in your lab report.
If x[n] represents the digital music signal and y[n] is the output from the digital filter, implement the following filters in MATLAB and apply them to the music:
Can you identify each filter as low-pass or high-pass? Does this agree with your understanding of the associated difference equation?
Digital filters are widely used in modern systems. Digital filters are nothing more than discrete-time systems that are described by difference equations! Digital filters are often executed on DSP chips that are specially designed to execute multiply-and-add operations very fast.
You can listen to each file from a web browser,
or you can
download each file into your filespace and read it into Matlab
with the commands:
y1 = auread('out1.au');