Simple truncation of the reflections in the impulse response of loudspeakers measured in normal rooms will increasingly falsify the response below about 500 Hz for typical situations. Well-known experience and guidance from loudspeaker models allow the determination of the lowest frequency for which truncation suffices. This paper proposes two additional strategies for achieving much improved low-frequency responses that are complementary to the easily-obtained high-frequency response: (a) a previously published nearfield measurement which can be diffractively transformed to a farfield response with appropriate calculations, here presented with greatly simplified computations, and (b) a measurement setup that admits only a single floor reflection which can be iteratively corrected at low frequencies. Theory and examples of each method are presented.
