2003 October, Volume 51 Number 10

CONTENT

PAPERS

Two-Port Representation of the Connection between Horn Driver and Horn
Gottfried K. Behler and Michael Makarski   883
Analyzing a loudspeaker system comprised of a horn and a horn driver is more productive if each element is modeled with an approach that is appropriate to the underlying physics. The driver element approximates a classical two port, with electrical voltage and current at the input port and acoustic pressure and velocity at the output port. In contrast, the horn element incorporates a three-dimensional sound radiation pattern with a one-dimensional acoustic input. The model of each element was merged at the connection point to predict the performance of the system's combination.

ENGINEERING REPORTS

Sensitivity of High-Order Loudspeaker Crossover Networks with All-Pass Response
Brandon Cochenour, Carlos Chai, and David A. Rich   898
While component tolerances influence the properties of loudspeaker crossover networks and these influences are greatest in high-order filters, the advantages of high-order networks dwarf other issues. Specifically as a listener changes his elevation, the shift in delay among noncoincident drivers dominates the frequency response. High-order filters limit this influence to a narrow-frequency region. Monte Carlo simulations confirmed that the component tolerances, in comparison to delay changes, are a minor aspect of the response.

Wavefront Sculpture Technology
Marcel Urban, Christian Heil, and Paul Bauman   912
Arrays of discrete loudspeakers are useful for creating a controlled sound field over a wide area, but mathematical and numeric methods often do not provide intuitive insight into the physical process. Using the visual analog of a Fresnel analysis, the authors considered a qualitative approach to the design of loudspeaker arrays to show how interference can be controlled. When this approach was applied to a curved array, the added degree of freedom enabled a wave field to be created that is free of destructive interference over a larger predefined area.

Acoustical Renovation of Tainan Municipal Cultural Center Auditorium
Weihwa Chiang, Chingtsung Hwang, and Yenkun Hsu   933
The Tainan auditorium had a reputation for good acoustics, but its reverberation time and spatial acoustics were inadequate for orchestra performances. Because the ceiling had been damaged, the renovation project also offered an opportunity to modify the acoustics. Scale models of the proposed changes were used to compare the conditions before and after the renovation. Simple modifications of the space produced dramatic improvements.

FEATURES

24th Conference Report, Banff   946
Advances in Low Bit-Rate Audio Coding   956
Review of Society's Sustaining Members   965
Updates and Corrections to the 2002/2003 International Sections Directory   983

DEPARTMENTS

Review of Acoustical Patents   943
News of the Sections   985
Sound Track   988
Upcoming Meetings   988
New Products and Developments   989
Advertiser Internet Directory   991
Available Literature   992
Membership Information   993
AES Special Publications   997
Sections Contacts Directory   1002
AES Conventions and Conferences   1008

FPO For the cover:

2003 October, Volume 51 Number 10

spine: 2003 October, Volume 51 Number 10