A New Signal for Measuring Loudspeaker Maximum Linear SPL
Roger Schwenke
To determine which loudspeakers are sized appropriately for a particular application, it is necessary to have a standard test signal. Test signals exists which intend to represent the frequency-dependent root mean square (RMS) level of typical content. However, the peak-to-average ratio (crest factor) of typical signals is also important for determining the maximum level a loudspeaker can attain. The crest factor of real signals as a function of frequency has been investigated and it is found that the crest factor increases with increasing frequency. On the other hand, the crest factor of pink noise and other standard noise signals changes minimally with frequency. A new test signal with the crest factor as a function of frequency is modeled after real signals. A procedure for finding the maximum sound pressure level (SPL) at which a loudspeaker can reproduce this signal linearly is proposed. Both the signal and the procedure have been made publicly available so that comparable measurements can be made by multiple, independent individuals.
Print ISSN
1545-0279
Electronic ISSN
2160-2492
Published
2020-06
Content type
Original Research
Keywords
Coherence, crest factor, distortion measurement, loudspeaker headroom, maximum sound pressure level (SPL), onset of nonlinearity, peak to average ratio, test signal