The frequency response is the output level or sensitivity of a microphone over its operating range from lowest to highest frequencies.

A flat frequency response is usually desired for applications where the sound source has to be reproduced without changing or “coloring” the original sound. All audible frequencies (20 Hz – 20 kHz) have the same output level.

Microphone flat and tailored frequency response
Microphone flat and tailored frequency response

A microphone with tailored frequency response is usually designed to enhance a sound source in a particular application. For instance, a microphone may have a peak in the 2 – 8 kHz range to increase intelligibility for live vocals.

Microphone Transducer Types: Comparison of dynamic microphone and condenser microphone frequency response
Microphone Transducer Types: Comparison of dynamic microphone and condenser microphone frequency response

Microphones with adjustable frequency response offer sound signature customization that goes beyond (e.g. low-cut) filter options.