Equalizers invert measured system impulse responses to flatten magnitude response

Evidence

Another type of equalizer is the parametric equalizer, which is used to adjust the level of a desired frequency band, its bandwidth, and centre frequency. An efficient way to compensate for magnitude response errors of LTI systems is the use of digital filters. If the original impulse response is measured to be h(n), the EQ filter to flatten it is the inverse filter with the z transform H−1(z) = 1/H(z). When such a filter is connected in cascade with the original system, the resulting response will, in theory, be the ideal flat magnitude response and with constant delay. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 522

Categorization

• DEFINE: Defines parametric equalizer and explains the inverse-filter z-transform approach to flattening an LTI system’s response.