Audio Filter Design

Designing active filters for crossovers, equalization, and signal processing.

Active filters using op-amps are essential for audio processing. From speaker crossovers to parametric equalizers, filter design shapes the frequency response of audio systems.

Objectives

  • Design Sallen-Key and state-variable filters
  • Implement Butterworth, Chebyshev, and Linkwitz-Riley responses
  • Build active crossover networks
  • Understand filter order and slope relationships
  • Select appropriate Q values for different applications

Key Takeaways

  • Sallen-Key is simplest for 2nd-order filters
  • Linkwitz-Riley crossovers sum flat
  • Higher order = steeper slope but more phase shift
  • Component matching critical for stereo applications