Convention Paper
True Quasi-Anechoic Loudspeaker Measurements in Normal Rooms
Convention Paper · Paper 10688 · June 2024
Abstract
Quasi-anechoic measurement of loudspeakers involves time-gating of the measured impulse response to remove room reflections. The resulting response has low-frequency errors that require an additional nearfield measurement whose response can be stitched to that of the higher frequencies. The net response suffers from errors due to cabinet diffraction, which cannot be cured by the various techniques that exist in the literature. In this paper we show how nearfield measurements of box loudspeakers can be corrected to represent farfield behaviour, with a minimum burden of assumptions and calculation, thus achieving a proper full-band measurement. The key is to use a calculation of cabinet diffraction to convert the supporting nearfield measurements to farfield ones, which complement the time-gated farfield. Theory and examples of the approach are presented.
