Equalization adjusts sound by perceived timbre, not measured accuracy

Evidence

A related and important area of signal processing to filtering is equalization. Unlike filtering, equalization is not interested in removing frequency components but in selectively boosting, cutting or reducing them to achieve a desired effect. The process of equalization can be modeled as a process of adding or subtracting a filtered version of the signal from the signal, as shown in Figure 7.40. Adding the filtered version gives a boost to the frequencies selected by the filter, whereas subtracting the filtered output reduces the frequency component amplitudes in the filter’s frequency range. The filter can be a simple highor low-pass filter, which results in a treble or bass tone control, or it can be a band-pass filter to give a bellshaped response curve. The cutoff frequencies of the filters may be either fixed or variable depending on the implementation. In addition, the bandwidths of the band-pass filters and, less commonly, the slopes of the highand low-pass filters can be varied. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2419 (#expands, via linked claim)

An alternative goal of sound reproduction is to control the sound field within the loudspeaker set-up. This means that the pressure and velocity waves originating from the virtual sources are to be synthesized as plane waves or as spherical waves. The targeted sound field would then be well defined, and the reproduced sound field can also be simulated, or even measured. Unfortunately, the errors in the synthesis of the sound field between the targeted and reproduced fields do not say much about the perceptual significance of the deviation. Sometimes a small difference in the wave field causes a large perceptual deviation, and a large deviation in the wave field may be perceptually irrelevant in some cases. However, the advantage of this starting point is that the reproduction techniques can be derived mathematically. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1902 (#expands, via linked claim)

Categorization

• XREF: connects to: Equalizer adjustments at specific frequencies produce predictable perceptual shifts in timbre; Equalization selectively boosts or cuts frequencies rather than removing them — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2419; Perceived loudspeaker sound quality depends only on amplitude responses — Toole, Floyd E, Sound reproduction- the acoustics and…, 711 (+4 more)

Broader Connections

• Equalizer adjustments at specific frequencies produce predictable perceptual shifts in timbre #expands (0.85)
• Equalization selectively boosts or cuts frequencies rather than removing them #expands (0.82) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2419
• Physical accuracy of a sound field does not predict perceived accuracy #expands (0.80) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1902
• Perceived loudspeaker sound quality depends only on amplitude responses #contradicts (0.78) — Toole, Floyd E, Sound reproduction- the acoustics and…, 711