ELEC 320, Fall 1998
Prof. Rich Kozick

Laboratory 2
Time-Domain View of Analog Filters and
Digital Filtering with MATLAB

  1. Please finish Lab 1 as follows:

  2. What questions do you have about MATLAB? Are there any concepts from the homework assignments that are not clear?

  3. Please download the MATLAB program digmus.m, which reads in a file with digitized music. You will have an opportunity to apply various digital filters to the music and listen to the results.

    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.


  1. Original music: slove.au
  2. Result of filter 1 with N = 5: out1.au
  3. Result of filter 2 with a = 0.9: out2.au
  4. Result of filter 3: out3.au

You can listen to each file from Netscape. Or, you can download each file into your directory. Then to read the sound file into MATLAB and listen to it:

y1 = auread('out1.au');