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Convention Paper

Higher Order Harmonic Signature Analysis for Loudspeaker Defect Detection

Authors: Anthony, Jamie; Celmer, Robert; Foley, Dan; Pagliaro, Tony; Sachwald, Benjamin; Thompson, Shane

AES Convention 117 · Paper 6251 · October 2004

Abstract

Loudspeaker assembly faults, such as a rubbing voice coil, bent frame, loose spider, etc., have traditionally been detected using experienced human listeners at the end of a production line. Previous attempts to develop production measurement systems for on-line testing typically analyze only low-order harmonics for the primary purpose of measuring total harmonic distortion (THD), and thus are not specifically designed to detect defective rub, buzz, and ticking sounds. This paper describes a new method wherein the total energy of high-order harmonics groups, for example, 10th through the 20th or 31st through the 40th, are measured and analyzed. By grouping high-order harmonics and resolving their respective total energies, distinct signatures can be obtained that correlate to the root cause of audible rub and buzz distortions (Temme, 2000). The paper discusses loudspeakers tested with specific defects, as well as results of a computer-based electroacoustic measurement and analysis system used for detection.

Details

Published in
AES Convention 117
AES Convention
117
Paper number
6251
Publication date
October 6, 2004
Session subject
Loudspeakers
Affiliation
Listen, Inc., Boston, MA ; College of Engineering, University of Hartford, West Hartford, CT (See document for exact affiliation information.)
Type
Convention Paper