Frequency response – The variation in output level or sensitivity of a microphone over its useable range from lowest to highest frequency. Virtually all microphone manufacturers will list the frequency response of their microphones as a range, for example 20 – 20,000Hz. This is usually illustrated with a graph that indicates relative amplitude at each frequency. The graph has the frequency in Hz on the x-axis and relative response in decibels on the y-axis.
Shure 55SHII Shure 55SH Series II Dynamic Microphone (the Elvis Microphone)
A microphone whose response is equal at all frequencies is said to have a “flat” frequency response. These microphones typically have a wide frequency range. Flat response microphones tend to be used to reproduce sound sources without coloring the original source. This is usually desired in reproducing instruments such as acoustic guitars or pianos. It is also common for stereo miking techniques and distant miking techniques.
PG27-LC Cardioid Condenser XLR Microphone
A microphone whose response has peaks or dips in certain frequency areas is said to have a “shaped” response. This response is designed to enhance a frequency range that is specific to a given sound source. For instance, a microphone may have a peak in the 2-10Khz range to enhance the intelligibility or presence of vocals. This shape is said to have a “presence peak”. A microphone’s response may also be reduced at other frequencies. One example of this is a low frequency roll-off to reduce unwanted “boominess”. Although dynamic microphones and condenser microphones may have similar published frequency response specifications their sound qualities can be quite different. A primary aspect of this difference is in their transient response.
