SC-04-03 meeting, Dublin, Ireland, 2019-03

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, Paul Treleaven, Bjorn Kolbrek, Benjamin Zenker, Jeroen De Rylke, Alfred Svobodnik, John Woodgate, Geoff Hill, Murilo Alvares, Phil Knight, Wolfgang Klippel, Steven Temme, Calam Shackelford, Michael Hedges, Christopher Wells, John Somberg, Pietro Massini, Joel Britto, Brian McLaughlin, Balazs Kakonyi, Richard Cabot, via online: Jeff Berryman, Anthony Kuzub, Stephen Scott

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.

The chair announced that David Murphy and Geoff Hill have volunteered to become vice-chairs of the working group.

Projects assigned to this group but not mentioned here had no action requested or required - see for details.

Open projects

AES-X223: Loudspeaker Driver Correlation Chamber: Information Document:
Scope: Information document explaining factors affecting the interchangeability of measurement data from simple loudspeaker comparison chambers.

Status: Call for comment draft is posted, comments close 2019/4/16, publication is scheduled for late April or early May, 2019.

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: A parameter list has been posted for comment, feedback is requested. The next version of the draft will consider tolerances.

Discussion notes: Scope should be reviewed and possibly updated. Characteristics list in spreadsheet form to be updated with a description to describe how information should be organized & feedback submitted. Additional characteristics beyond basic EoL should be considered for "inside" data use pertinent to identifying trends in tolerance shift. Reference to X223, test enclosures should be included

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. A key aspect is to clarify definition of life testing finding a satisfactory reliability test. Accelerated Reliability testing: Power testing procedures are being discussed with many opinions. Workshop W01 at the 146th addressed "Loudspeaker Reliability Test Signals"

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: Reaffirmation required in 2019

Discussion: It is recommended that the committee should review the document before reaffirmation and additionally, the Standards Chair recommends reviewing AES5-id.

The group should also consider if next revision should include updates for multiple enclosure systems or consider a separate new document. It should also consider including time domain measurements.

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: First draft by David Murphy is posted to the repository.

Discussion: Vice-chair David Murphy is reviewing next updates & waiting feedback.

Target: Draft fall 2020


W Klippel reported that IEC 60268-21 on loudspeaker drivers has been released, IEC 60268-22 on loudspeaker systems will be released in December 2019.

New Projects

There were no new projects.

New Business

There was no new business.

The next meeting will be scheduled in conjunction with the AES 147th Convention, to be held October 2019 in New York, NY, US.

AES - Audio Engineering Society