The Sampling Theorem

How fast is fast enough?

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Sampling above $2 f_{\max}$ captures a band-limited signal perfectly.
• Half the sample rate is the Nyquist frequency.
• Anti-aliasing filters remove frequencies above it before sampling.

Steps

1. Twice the highest frequency
2. Why 44,100?
3. Perfect reconstruction
4. Recording bats
5. An ultrasonic ghost
6. Telephone voices