| 2006 May, Volume 54 Number 5 |
CONTENTS
PAPERS
Low-Frequency Optimization Using Multiple Subwoofers
Todd Welti and Allan Devantier 347
The acoustic environment of a sound system has a strong influence on the sound quality at low frequencies, especially in small spaces. As a result there is an interest in solutions that improve the performance. While conventional approaches tend to focus on signal processing, the proposed solution introduces the location of subwoofers as the major variable, with the addition of minimal signal processing. Using a metric that optimizes performance in multiple seats, a robust solution becomes available.
Identification of Quality Attributes of Spatial Audio by Repertory Grid Technique
Jan Berg and Francis Rumsey 365
In order to evaluate spatial quality of audio reproduction, it is first necessary to select a method that can identify the relevant attributes. Being a relatively new field, spatial audio does not yet have a well-established list of such attributes. As an extension of the work of Kelly, the authors apply the repertory grid technique, which is based on subjects' personal reflections of the stimuli. Because subjects describe the way in which triads of stimuli differ, the attributes are elicited rather than constructed by the experimenter. The results are consistent with the findings from other methods utilized, thus demonstrating the validity of this approach when used in spatial audio.
Conversion of Discretely Sampled Sound Field Data to Auralization Formats
Bård Støfringsdal and U. Peter Svensson 380
Sound field simulations often use finite-element or other mesh-based methods, which produce output data that must first be converted to an intermediate format in order to be compatible with conventional auralization techniques. The proposed method converts sampled mesh data to a series of plane waves using a circular array of virtual sources. While not a perfect conversion of an arbitrary sound field, this approach provides a stable frequency-domain representation which minimizes the error in a least squares sense. Such reproduction errors should be acceptable in most practical cases. Results for two dimensions are readily extensible to three dimensions.
Compensating the Response of Near-Field Loudspeaker Monitors to Minimize the Effects of Desktop Acoustic Loading
Andrew Goldberg, Aki Mäkivirta, and Ari Varla 401
When two-way loudspeakers are mounted on or near mixing consoles, acoustical loading detrimentally changes the response. Acoustical loading systematically raises the response in the 100- to 250-Hz region, and reflections at mid and high frequencies make a comb filtering effect. In an extensive study, 80% of the cases exhibited low-frequency one-sixth octave peaks of about 4 to 6 dB. A single second-order notch filter, appropriately designed, removes much of the negative effects of nearby mixing consoles, desktops, and work surfaces.
LETTERS TO THE EDITOR
Comments on "Perception of Modal Distribution Metrics in Critical Listening Spaces-Dependence on Room Aspect Ratios"
Earl Geddes 412
Authors' Reply
B. M. Fazenda, M. R. Avis, and W. J. Davies 412
STANDARDS AND INFORMATION DOCUMENTS
AES Standards Committee News 414
Audio file format for interchange; high-resolution multichannel audio interconnection (HRMAI)
FEATURES
Automotive Audio Update 416
Loudness Trumps Everything 421
30th Conference, Saariselkä, Finland, Call for Papers 440
DEPARTMENTS
News of the Sections 424
Sound Track 428
New Products and Developments 429
Upcoming Meetings 429
Available Literature 430
Membership Information 431
Advertiser Internet Directory 437
Sections Contacts Directory 441
AES Conventions and Conferences 448
FPO For the cover:
2006 May, Volume 54 Number 5
spine: 2006 May, Volume 54 Number 5