AES Journal

Journal of the AES

2003 July/August - Volume 51 Number 7/8


Full-Sphere Sound Field of Constant-Beamwidth Transducer (CBT) Loudspeaker Line Arrays (PDF-1.6MB)  
D. B. (Don) Keele, Jr.    611
Unlike a linear-line array of loudspeakers, which has no means of controlling the horizontal beamwidth, a curved-line circular-arc array exhibits useful properties in three dimensions. Based on a computer simulation, the author shows that the configuration provides horizontal directivity in addition to the expected vertical control. Such arrays have a pear-shaped pattern that is surprisingly uniform over the frequency range. The bending is an extra degree of freedom that allows more control over the radiation pattern.  

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Direct-Radiator Loudspeaker Systems with High Bl (PDF-294K)  
John Vanderkooy, Paul M. Boers, and Ronald M. Aarts    625
Increasing the magnetic motor strength of a driver not only improves the efficiency of the loudspeaker and amplifier, but also improves other tradeoffs in the design process. Box volume can be decreased. A study demonstrated the advantages for a small sealed-box configuration, although equalization is required to restore a flat response. Vented systems do not benefit as much from this approach.  

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Psychoacoustic Investigations On Sound-Source Occlusion (PDF-298K)  
Hania Farag, Jens Blauert, and Onsy Abdel Alim    635
Virtual space simulation is actually a collection of acoustic attributes, which include objects that cast auditory shadows, an effect known as occlusion. Objects block and change the perception of sound when they are located between the source and the listener. Experiments show that the perceived location of an occluded source is shifted to the edge closest to the listener, which simplifies the computational burden of modeling occluding objects. This result is consistent with the precedence effect.  

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The Differential Pressure Synthesis Method for Efficient Acoustic Pressure Estimation (PDF-190K)  
Yufei Tao, Anthony I. Tew, and Stuart J. Porter    647
Calculating the sound field around a complex object, such as the pressure at the two ears of a head, is computationally intensive. Rather than a direct computation, the authors demonstrate an incremental approach to a reference template. The pressure changes produced by each spherical harmonic are precomputed and stored in a database. The target shape is then decomposed into the template references and the sum of spherical harmonics, each of which contributes an incremental change to the pressure. In the case of a dummy head, the results were accurate for wavelengths that were large compared to the spatial perturbations.  

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Comments on "Deciphering an Enigma" (PDF-12K)  
Marianna Sankiewicz and Gustaw Budzynski    657
Author's Reply to "Comments on 'Deciphering an Enigma'" (PDF-12K)  
Steven Harris    657
AES47-2002 AES standard for digital audio-Digital input-output interfacing-Transmission of digital audio over asynchronous transfer mode (ATM) networks (PDF-142K)    659
AES-R4-2002 AES standards project report-Guidelines for AES standard for digital audio- Digital input-output interfacing-Transmission of digital audio over asynchronous transfer mode (ATM) networks, AES47 (PDF-104K)    684
AES Standards Committee News (PDF-28K)    704
Mechanical media; audio storage and handling; listening tests; audio connectors; grounding and EMC; audio file transfer and exchange  
115th Convention Preview, New York (PDF-288K)    714
     Calendar (PDF-104K)    716
     Exhibitors (PDF-2.0MB)    717
     Exhibit Previews (PDF-5.1MB)    722
Demystifying Audio Metadata (PDF-759K)    744
116th Convention, Berlin, Call for Papers (PDF-35K)    768
25th Conference, London, Call for Papers (PDF-16K)    769
Review of Acoustical Patents (PDF-1.5MB)    710
News of the Sections (PDF-106K)    752
Sound Track (PDF-72K)    756
Available Literature (PDF-18K)    757
Upcoming Meetings (PDF-13K)    758
Membership Information (PDF-121K)    759
Advertiser Internet Directory (PDF-35K)    762
In Memoriam (PDF-109K)    766
Sections Contacts Directory (PDF-33K)    770
AES Conventions and Conferences (PDF-47K)    776
Cover & Sustaining Members List (PDF-33K)    
VIP List & Editorial Staff (PDF-26K)    
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AES - Audio Engineering Society