Professor Kettlewick

Study level

First-year university

The second half of every lecture goes on to first-year university: the derivations, the general formulas and harder problems.

Lectures at this level

Lecture 1

Sound, signals and sampling

  1. Show that ff and f+kfsf + kf_s give identical samples, and calculate any alias frequency by folding.
  2. Explain why the anti-aliasing filter must be steep, and how oversampling eases it.
  3. Explain reconstruction: why, ideally, a filtered DAC output is the original band-limited wave, not a staircase.

Notes: Frequencies that give the same samples · Finding any alias · How steep the filter must be, and oversampling · Getting the wave back

2 worked examples from the video (L1-Q5, L1-Q6) · 6 practice questions