Entries by Zarina

Evaluation of Loudspeaker Performance at Low Frequencies

Authors: Steve Temme and Christopher J Struck Evaluation of loudspeaker performance at low frequencies is complicated by long wavelengths, room interaction and cabinet/baffle diffraction. Since low frequency measurements have traditionally required large, impractical testing environments, different techniques have been developed in an attempt to overcome this requirement. Anechoic chambers, outdoor measurements, half-space measurements, ground plane […]

Audio Distortion Measurements

Author: Steve Temme In the never ending quest for better sound transmission, reinforcement, and reproduction, the electronics have been extensively analyzed for distortion. Distortion in the electroacoustic transducers, while typically several orders of magnitude greater, has often been neglected or not even specified because it has been difficult to measure and interpret. With a basic […]

Time Selective Measurements with a Logarithmically Swept Sine

Author: Martin Rung A time selective measurement of a frequency response is (directly or indirectly) based on a measurement of the impulse response, where a well-defined time window is applied to the impulse response. The frequency response is simply the Fourier transform of the impulse response. Time selective measurements are often used in electroacoustics to […]

How to Graph Distortion Measurements

Distortion curves are conventionally plotted under the corresponding excitation frequency of the measured fundamental. Interpretation of results can be misleading due to the influence that the passband shape and amplitude irregularities of the fundamental response have on the distortion responses. By ‘amplitude normalizing’ the distortion responses to the measured fundamental response before plotting them at […]

Simulated Free Field Measurements

The development of time selective techniques has enabled measurements of the free field response of a loudspeaker to be performed without the need for an anechoic chamber. The low frequency resolution of both time selective techniques and anechoic measurements is, however, limited by the size of the room. A technique is presented enabling measurements of […]