2004 October, Volume 52 Number 10

CONTENT

PAPERS

Subjective Investigations of Inverse Filtering
Scott G. Norcross, Gilbert A. Soulodre, and Michel C. Lavoie   1003
Much of the research on inverse filtering to correct room or loudspeaker irregularities assumes (without confirmation) that such techniques will improve the subjective listening experience. When this assumption is carefully tested, surprisingly, many techniques actually degrade overall audio quality rather than improve it. Two kinds of inverse filtering were tested: time-domain least squares and frequency deconvolution. Some additional techniques avoided perceptual artifacts but with an inconsistent amount of improvement.

Analysis of a Folded Acoustic Horn
Andrew Bright, Keith Holland, and Frank J. Fahy   1029
Advanced analysis techniques, such as the boundary-element method (BEM), show that a folded horn can be represented by a one-parameter model at low frequencies. Such a model is able to reproduce the throat and transfer impedances as well as the pressure response with high accuracy below 300 Hz. At higher frequencies a more complex model is required. Although the BEM method can contribute to understanding low-frequency folded horns, it remains a complex analysis technique requiring specialized skills.

The Distributed Edge Dipole (DED) Model for Cabinet Diffraction Effects
M. Urban, C. Heil, C. Pignon, C. Combet, and P. Bauman   1043
A simple model, called distributed edge dipole, is proposed to explain the effects of cabinet edge diffraction on the radiated sound from a direct-radiating loudspeaker when mounted in an enclosure. In comparison to two other techniques, the proposed model more accurately predicts measurements of a thin circular baffle over 50 to 1000 Hz and over a wide angular range from 0 to180 degrees. More specifically, the improvements were obtained in the boundary region between the forward and backward directions.

COMMUNICATIONS

Subjective Loudspeaker Testing for Accuracy
David Lloyd ben Yaacov Yehuda Klepper   1060
Discussions about subjective loudspeaker preferences often ignore the need for a rating scale to evaluate accuracy. Preferences and accuracy are different perceptual qualities. Accuracy relates to the degree to which a reproduced sound field is subjectively equivalent to a corresponding live presentation of the same source. There is no proof that preferences among different individuals will match accuracy.

STANDARDS AND INFORMATION DOCUMENTS

AES Standards Committee News   1065
Microphone measurement

FEATURES

A Symposium on Multichannel Audio for Radio Broadcasters   1066
Review of Society's Sustaining Members   1072
118th Convention, Barcelona, Call for Papers   1111
26th Conference, Denver, Call for Papers   1112

DEPARTMENTS

Reviews of Acoustical Patents   1062
News of the Sections   1094
Upcoming Meetings   1097
Advertiser Internet Directory   1097
Sound Track   1098
New Products and Developments   1100
Available Literature   1102
Membership Information   1103
In Memoriam   1110
Sections Contacts Directory   1113
AES Conventions and Conferences   1120

FPO For the cover:

2004 October, Volume 52 Number 10

spine: 2004 October, Volume 52 Number 10