2010 Winter Symposium Technical Papers - Review
Abstracts of presented papers are included below. The full papers may be downloaded using the links below. Please note that these links will take you to the ALMA Download Manager. Registration and ALMA membership is required to view these links.
Induction Drive Loudspeakers: Download Paper
Authors: Marshall Buck (Presenting), David Graebener, Patrick Turnmire
Induction loudspeaker motors use a transformer with fixed primary and moving secondary in a static magnetic field. FEA modeling has driven this technology forward. We have built very high efficiency, mid/high compression drivers, and a linear, long stroke woofer with high output.
The mid exhibits an output of over 80 acoustic watts, and a maximum 10 Watt efficiency of 45%. Reliability of induction drive is high due to the elimination of moving lead in wires.
Presenter Bio: Marshall Buck
Marshall Buck earned a Ph.D. in Physiological Psychology from UCLA. He is an audio engineer specializing in transducers and systems for over 30 years. Dr. Buck is president of Psychotechnology, Inc. He is a past president and treasurer of the AES. He is an AES Life Fellow and was awarded the AES Distinguished Service Medal. Dr. Buck has presented over 30 technical papers, and holds a number of patents.
New Method for Measurement of Rub & Buzz Based on a Perceptual Model: Download Paper
Author: Steve Temme, Listen, Inc.
Manufacturing defects in loudspeaker production can often be identified by an increase in Rub & Buzz distortion. This type of distortion is quite noticeable because it contributes an edgy sound to the reproduction and is annoying because it often sounds separate or disembodied from the fundamental signal. The annoyance of Rub & Buzz distortion is tied intimately to human perception of sound and psychoacoustics. To properly implement automated production-line testing of loudspeaker Rub & Buzz defects, one has to model or imitate the hearing process using a sufficiently accurate perceptual model. This paper describes the results of a Rub & Buzz detection system using a simplified perceptual model based on human masking thresholds that yields excellent results
Presenter Bio: Steve Temme
Steve Temme is founder and President of Listen, Inc. a manufacturer of software-based measurement systems for testing electro-acoustic and audio electronic products. Prior to founding Listen, Steve worked for many years as an acoustic test and measurement applications engineer at Brüel & Kjær, and also as a loudspeaker design engineer at Apogee Acoustics. He has authored numerous papers on acoustic testing and lectured extensively throughout the world.
The Subjective and Objective Evaluation of Room Correction Products: Download Paper
Authors: Dr. Sean E. Olive, John Jackson, Allan Devantier, David Hunt, Sean M. Hess, Harman International
A panel of eight trained listeners gave comparative ratings for five different room correction products based on overall preference and spectral balance. The room corrections were applied to a single loudspeaker/subwoofer in a typical semi-reflective listening room, and evaluated using three different music programs. The same loudspeaker/subwoofer without correction was included as a hidden anchor. The results found significant differences in sound quality among the room correction products based on listeners’ preferences and spectral balance ratings. These differences can be largely explained by examining the steady state, spatially averaged frequency response measurements of the room corrections measured at the listening location.
Presenter Bio: Dr. Sean Olive, Harman International
Sean is Director of Acoustic Research for Harman International, a major manufacturer of audio products for consumer, professional and automotive spaces. He directs the Corporate R&D group, and oversees the subjective evaluation of new audio products including Harman's OEM automotive audio systems. Prior to 1993, he was a research scientist at the National Research Council of Canada where his research focused on the perception and measurement of loudspeakers, listening rooms, and microphones. Sean received a Bachelors in Music from the University of Toronto, and his Masters and Ph.D. degrees in Sound Recording from McGill University in Montreal. He has written over 25 research papers on the perception and measurement of audio for which he was awarded the Audio Engineering Society (AES) Fellowship Award in 1996, and two Publication Awards (1990 and 1995). Sean is the current Vice President for the AES Western US-Canada region.
ALMA Winter Symposium 2010 Review:
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