Audio Fundamentals
Frequency response describes how evenly an audio device reproduces different frequencies within the audible range. It shows whether the system amplifies or attenuates certain frequencies compared to others, revealing how accurate or coloured its sound is.
Frequency response is a key specification in all audio equipment, indicating the range of frequencies a device can handle and how consistently it reproduces them. It is usually expressed as a range (for example, 20 Hz–20 kHz) along with a tolerance in decibels (such as ±1 dB). This tells you not only how wide the range is but also how flat the response remains across it.
A perfectly flat frequency response means that every frequency is reproduced at the same level as the original signal. In reality, all systems exhibit some variation. Microphones, loudspeakers, amplifiers, and analogue tape recorders each have characteristic response curves that define their sonic character.
In digital systems, the frequency response is determined mainly by the sample rate, converter design, and any filtering applied during conversion. Analogue equipment, on the other hand, is affected by circuit design, component tolerances, and magnetic or acoustic limitations.
Engineers measure frequency response using test tones or sweeps, displaying the results as a graph of amplitude versus frequency. A wide and flat response is generally preferred for accurate monitoring and recording, though intentional deviations, such as gentle roll-offs or resonant peaks, can contribute to a desired tonal signature.
