Near Field

The sound field very close to the audio source is called the near field. “Very close” in this case means less than one wavelength at the frequency(s) of interest. Near field is a phrase we hear thrown around a lot these days due to the popularity of monitoring systems commonly known as nearfield monitors. Technically, however, nearfield monitors aren’t truly used in the near field most of the time. Even at a relatively low frequency like 400Hz, the near field stops less than three feet from the speaker, beyond which one is typically in some cross between an approximation of a Free Field and Far Field (or Mid Field). The idea behind near field monitors is that, since the listener is so much closer to the speakers than the surrounding walls, floor, and ceiling, their effect on the sound is minimized as stated in the Inverse Square Law. Thus the term near field can be appropriate as a reference to being relatively near the listener compared to other objects in a room, including the larger studio monitors.