Report of the meeting of the SC-04-03 Working Group on loudspeaker modeling and measurement of the SC-04 Subcommittee on Acoustics, held in New York, NY, USA, 2019-10-17.
The meeting was convened by chair S. Hutt.
Present were Steve Hutt, Geoff Hill, Steven Temme, Pietro Massini, Brian McLaughlin, Balazs Kakonyi, Richard Cabot, David Murphy, Ed Simon, Charlie Hughes, David Blore, Sebastien Degraeve, Michae Poimboeuf, Chrstopher Struck, Jorge Serrano, Rafael Serra, Scott Orth, Fabio Blasizzo, Jonathan Gerbet, Jay Kirsch, John Busenitz, Alex Voishvillo, Brian Long*, Filippo Bartolozzi*, Joel Brito*, Roger Schwenke*, Tim Gladwin* (* denotes by electronic link).
The formal notice on patent policy was read.
The agenda and the report of the previous meeting, held in Dublin, Ireland, 2019-03-21, were approved as written.
AES2-R Review of AES2-2012: AES standard for acoustics - Methods of measuring and specifying the performance of loudspeakers for professional applications - Drive units
Scope: This Recommended Practice establishes a set of primary specifications to be followed by manufacturers in describing loudspeaker components used in professional audio and sound-reinforcement system design.
Status: Reaffirmed in 2017
Discussion: The next revision, expected in 2023, is being approached as a total rewrite. The power test duration was discussed, 2 hours vs. 100 hours. The group is working on finding a satisfactory reliability test. The amplifier requirements for peak voltage testing requires further discussion. Crest Factor peaks may be misconstrued depending on "silence" vs. peaks, meaning that periodicity of peaks should be considered.
AES56-R Review of AES56-2008 (r2014): AES standard on acoustics - Sound source modeling - Loudspeaker polar radiation measurements
Scope: to specify unified loudspeaker far-field polar radiation measurement practice to provide data suitable for room acoustic modeling programs.
Status: The reaffirmed version was just published.
AES73id-R AES information document for acoustics – Loudspeaker driver comparison chambers
Scope: Information document explaining factors affecting the interchangeability of measurement data from simple loudspeaker comparison chambers.
Status: The initial version was published.
Discussion notes: David Murphy and Geoff Hill will review volume vs. driver size relations.
AES-X168 Characterization of loudspeaker systems;
Scope: This document defines a set of characteristics of loudspeaker systems for inclusion in manufacturers’ specification documents, and identifies the relevant methods of measurement. It considers loudspeaker *systems* for professional applications. They may be combinations of active and passive sub-systems. It is intended for users and designers of loudspeaker system installations.
Status: The first draft by David Murphy is in the repository.
Discussion: IEC 60268-22 in development, to be monitored for content.
Target: Draft fall 2022
AES-X241 AES Standard for Acoustics - End of Line Testing for Production Loudspeaker Drivers
Scope: This standard specifies parameters and methods of measurement required for end-of-line quality control tests performed on loudspeaker drivers manufactured for automotive, consumer and professional applications. It includes requirements for mechanical setup. It does not consider measurements of loudspeaker systems or multi-driver arrangements.
Status: Gathering comments on draft, next stage to consider tolerances.
Discussion notes: John Busenitz and Pietro Massini will move the Characteristics list spreadsheet to google docs to improve information acquisition.
Liaisons:
Nothing to report.
New Projects
The AES-X250 project to determine MaxSPL using noise was started in Task Group SC04-03A chaired by Merlijn van Veen and Roger Schwenke. An online meeting and a face-to-face meeting at this convention were held which addressed the initial topic, set an agenda and goals. Plans for additional online meetings are in place. Interested parties should contact the Standards Manager.
New Business
There was no new business.
The next meeting will be held in Vienna, Austria 2020-05, in conjunction with the AES 148th convention.
