Filters

Summary

The "Filters" topic provides an introduction to what a filter is, some basic types of audio filter, and how a simple filter is calculated mathematically, first with a simple example, then with a general equation that can be used for many kinds of filter.

Lessons

1. Introduction to Filters

• Vocabulary
• Filter
• Digital Filter
• Timbre
• Spectrum
• Time Domain
• Frequency Domain
• Spectral Domain
• Sinusoidal Tone
• Complex Periodic Tone
• Impulse
• White Noise

2. Audio Filter Types

• Vocabulary
• Filter Types (lowpass, highpass, bandpass)
• Cutoff Frequency
• Center Frequency
• Passband
• Q (quality factor)
• Resonance
• EQ (equalization)

3. Simple Lowpass Filter

• Vocabulary
• Lowpass filter
• Difference equation
• Filter coefficients
• Impulse response
• Q (quality factor)
• Summation notation (sigma notation)
• Finite impulse response (FIR) filter

4. The General Filter Equation

• Vocabulary
• FIR
• IIR
• Feedforward
• Feedback
• Recursive
• Non-recursive
• Biquad Filter
• Comb Filter
• Order