Low-frequency cutoff defined at −10 dB, not −3 dB, best predicts perceived fidelity.

Evidence

The apparent preference for extended bass motivated Figure 2.5, where the low-cutoff frequencies for all of the loudspeakers were determined at two attenuation levels, −5 dB and −10 dB, relative to the reference 300–3000 Hz band. The normal −3 dB “half-power” level was also tried, but it yielded no relationship, which was anticipated because of the substantial effects of solid angle gains and bass resonances in small rooms. Therefore, it was not a total surprise to find that the relationship between “fidelity” rating and low-frequency cutoff reached a maximum correlation for cutoff frequencies determined at the −10 dB level. — Toole, Floyd E, Sound reproduction- the acoustics and…, 178

Categorization

• DEFINE: Establishes why the conventional −3 dB half-power cutoff fails in small rooms, warranting a −10 dB definition for bass-extension correlation.