frequency response
The range of audio frequencies a device can reproduce, typically measured in Hertz.
In Depth
Human hearing spans roughly 20 Hz to 20,000 Hz, and audio equipment is designed to cover this range as evenly as possible. Speakers, headphones, microphones, and rooms all have characteristic frequency responses that colour the sound. A perfectly flat frequency response reproduces all frequencies equally, but most equipment has peaks and dips. Understanding frequency response is essential for choosing equipment, treating rooms, and making informed EQ decisions during mixing.
Yamaha NS-10 studio monitors were industry standard for decades despite having a notoriously harsh frequency response; engineers reasoned that if a mix sounded good on NS-10s, it would sound good anywhere.