Loudspeaker Measurement - Nearfield Measurements

Nearfield Measurements

Room acoustics have much lower effect on nearfield measurements, so these can be appropriate when anechoic chamber analysis cannot be done. Measurements should be done at much lower distances from the speaker than the speaker (or the sound source, like horn, vent) overall diameter, where the half-wavelength of the sound is smaller than the speaker overall diameter. These measurements yield direct speaker effeiciency, or the average senstivtiy, without directional information. For a multiple sound source speaker system the measurement should be carried out for all sound sources (woofer, bass-reflex vent, midrange speaker, tweeter...). These measurements are easy to carry out, can be done at almost any room, more punctual than in-box measurements, and predicts half-space measurements, but without directivity information.