nearfieldpatroon

A nearfield pattern refers to the acoustic radiation from a sound source that is measured at a very close distance. This close proximity is typically within the source's "nearfield," a region where the sound waves are not yet fully developed and are influenced by the physical dimensions of the source itself. In contrast, the "farfield" is the region where the sound waves have propagated sufficiently to behave like spherical waves, with their characteristics primarily determined by the source's overall output and directionality.

Measuring a nearfield pattern can provide valuable insights into the behavior of a sound source that might not be apparent in farfield measurements. For loudspeakers, for instance, nearfield measurements can reveal information about the individual drivers and their acoustic interactions before they combine to form the overall farfield sound. This can be particularly useful in identifying and troubleshooting issues such as phase cancellations or resonances. Similarly, for acoustic radiators or transducers, nearfield measurements can help characterize the pressure distribution directly at the surface of the source.

The interpretation of nearfield patterns requires careful consideration of the measurement distance. As the distance decreases, the measured sound pressure and phase can vary significantly. This phenomenon is due to the reactive components of the acoustic field, which dominate in the nearfield. While nearfield measurements are not representative of how the sound will propagate in a listening environment, they are a powerful diagnostic tool for understanding the fundamental acoustic behavior of a sound source in its immediate vicinity.