Frequency response is the single most important measurable parameter of audio devices.

Evidence

The amplitude vs. frequency curve, which is known as the frequency response, is the single most important measurable parameter of any audio device, and the general objective is a smooth flat curve extending over the audible frequency range. However, that goal has yet to be universally achieved in our imperfect physical world. Consequently, especially in loudspeakers, we must learn how to evaluate the audible consequences of different kinds of deviation from the ideal—the audibility of tilts, peaks, dips, bumps and wiggles. — Toole, Floyd E, Sound reproduction- the acoustics and…, 947

Categorization

• DEFINE: Defines frequency response as the amplitude vs. frequency curve and states its primacy among audio measurements.