equalization

The accepted definition carves equalization as an operation that APPLIES a filter with a parameterized gain curve (bandwidth/Q, gain per band, filter topology). Remove the filter mechanism and the operation has no means of adjusting the response — it stops operating. EQ is an operation that applies a filter, not a kind of filter, so DEPENDS_ON is the correct arrow (the rejected zero-phase-filtering case was identity, not mechanism).

Equalization is a signal processing operation — it applies filter operations to shape frequency response. Remove signal processing techniques (filtering, spectral analysis) and equalization has no means to operate. Constitutive dependency.

Removal test (Law 8b): equalization operates on signals — it adjusts the relative amplitude of frequency components in an audio signal. Remove the signal and equalization has no material to process; it ceases to function. Same physical-interpretation precedent as accepted speaker→DEPENDS_ON signal, headphone-amplifier→DEPENDS_ON signal (pending).

Equalization is a human-made technique built and maintained for the sake of audio engineering practice: it provides the frequency-shaping operation used throughout recording chains, mastering, live sound, and sound design. Servant points at master per Law 8d. Consistent with accepted SERVES edges from signal-amplification→audio-engineering, tape-saturation→audio-engineering, phase-vocoder→audio-engineering.

equalization IS a type of signal processing technique. It modifies the frequency content of a signal — specifically adjusting the amplitude of certain frequency bands. A competent speaker would call it 'a signal processing technique.'

spectral-whitening is a specific kind of equalization — it reshapes the spectrum to achieve flatness. Direction test: spectral-whitening IS A case of general class equalization. Law 9.

De-essing is a specialized form of frequency-selective attenuation that targets sibilant frequencies. It operates as a dynamic equalizer — remove equalization capability and the de-esser has no mechanism for frequency-targeted gain reduction.

Pre-emphasis derives from equalization: it is a specific equalization curve (boosting high frequencies) that was developed for noise reduction in analog recording. Equalization existed first and fed into the development of pre-emphasis as a specialized form.

Frequency-weighting (A-weighting, C-weighting, etc.) derives from equalization: both adjust amplitude across frequency bands, but standardized frequency-weighting curves were developed as specific applications of the broader equalization concept for measurement and safety purposes. Chronology: general equalization predates standardized weighting curves.