SC-04-03 meeting, Online, 2023-05

Report of the meeting of the SC-04-03 Working Group on loudspeaker modeling and measurement, held online, 2023-05-05.

The meeting was convened by chair G. Hill.

Present were Geoff Hill, David Murphy, Rich Cabot, Jim Meyer, Steve Hutt, Stephen Thompson, John Woodgate, Daniele Ponteggia, James Hipperson, Tomlinson Holman, Scott Dorsey, Satoshi Oode, Charlie Hughes, Roger Schwenke.

The formal notice on patent policy was read.

The agenda and the report of the previous meeting, held in online, 2022-10-10, were approved as written.

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

Open projects

AES1id-R Review of AES-1id-2012 (r2017): AES Information Document for Acoustics - Plane-Wave Tubes - Design and Practice
Scope: To establish, expand, and improve the practice for the design and use of plane-wave tube measurement techniques, as recommended in section 2.2.1 of AES2-1984, "Recommended Practice Specification of Loudspeaker Components Used in Professional Audio and Sound Reinforcement."

Move to reaffirm

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.

Need to change or re-affirm in 2023, John Woodgate to re-affirm initially unless any definite proposals, decision was made to re-affirm AES2.

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.

A draft document is and has been available for some time, this needs to be reviewed by someone in THIS group to see if it is ready a Volunteer is therefore required! I asked if anyone had any information they could put forward at the moment? John commented that extensive documentation available, but nothing further has happened, we a committee need to decide if this goes forward!

Action Geoff to put this in the minutes that the documentation needs to be reviewed by someone in THIS group! So a Volunteer is therefore required!

AES-X241 AES Standard for Acoustics - End of Line Testing for Production Loudspeaker Drivers
Current 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.

A similar situation to X168 - the people who were championing this before, have moved on and no one seems willing to, or get involved, the question is there anyone in the wider committee membership who is so willing, would they come forward via e-mail etc.

The chair will send the amended scope to the entire group for comments, a subgroup to be formed to lead this effort, currently comprising David Prince, Peter Massini, Tim Gladwin and John Busenitz.

AES75 AES Standard for Acoustics - Measuring maximum linear peak SPL using noise
Scope: This standard specifies a method for measuring the maximum linear peak SPL of a loudspeaker driver or system. It uses a mathematically derived test signal that effectively emulates the dynamic characteristics of music as a function of frequency as well as its spectral content. The SC-04-03A task group has begun working on methods to spread awareness of the standard.


No Liaison reports.

New Projects


New Business

The Chair had an enquiry earlier this year regarding the lack of any Standardisation of Fractional Octave Smoothing, I looked for one as did Rich Cabot and John Woodgate. Currently we are not aware of any standards in this area, there are a series of papers. Daniele commented that there was one paper that summarised the field best, would this be an area suitable for us to consider?

There was an interesting discussion, with several members willing to explore this further, James Hipperson, Daniele Ponteggia, Jim Meyer and Roger Schwenke confirmed interest, I would be prepared to co-ordinate a working group and it was agreed that this could fit within the remit of X168

The next meeting will be held online in October 2023, scheduled in conjunction with the AES 155th Convention.

AES - Audio Engineering Society