Nonlinear equalization methods remain underdeveloped in audio engineering

Evidence

Compensation for non-linear distortion is more difficult than for linear response correction (Klippel, 2006), and the methods for non-linear EQ have not been developed very far. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 527

Categorization

• QUESTION: Why have nonlinear EQ methods not advanced far? Worth chasing the Klippel 2006 reference to understand the technical barrier.