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| Volume 51 Number 7/8 | 2003 July/August |
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CONTENT Download Entire Journal (12.8MB) |
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| PAPERS | |
| 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. | |
| Comment on this paper | |
| 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. | |
| Comment on this paper | |
| 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. | |
| Comment on this paper | |
| ENGINEERING REPORTS | |
| 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. | |
| Comment on this report | |
| LETTERS TO THE EDITOR | |
| 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 |
| STANDARDS AND INFORMATION DOCUMENTS | |
| 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 | |
| FEATURES | |
| 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 |
| DEPARTMENTS | |
| 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 |
| EXTRAS | |
| Cover & Sustaining Members List (PDF-33K) | |
| VIP List & Editorial Staff (PDF-26K) | |
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