SC-04-03 meeting, Online, 2023-10

Report of the meeting of the SC-04-03 Working Group on loudspeaker modeling and measurement, held online, 2023-10-13.

The meeting was convened by chair Charlie Hughes.

Present were Charlie Hughes, Steve Hutt, Rich Cabot, Jim Meyer, David Andrews, David Murphy, John Busenitz, Daniele Ponteggia, Geoff Hill, Roger Schwenke, James Hipperson, Steve Thompson, Tomlinson Holman

The formal notice on patent policy was read.

The agenda and the report of the previous meeting, held in online, 2023-05-05, were approved as written.

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

Open projects

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.

The decision was made to re-affirm AES2.

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.

An editorial revision was published earlier this year. RS gave a report on the efforts of SC-04-03-A and the status of AES75.

No further action is required until 2027 when this working group will either reaffirm or revise.

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.

DM had previously submitted a draft document for review. To date, no substantive review has occurred. DM commented that CEDIA is currently working on a similar standard. CH inquired about a formal liaison with CEDIA. DM will attempt to help establish this. DM also mentioned that he will make some revisions to his previous draft and resubmit to the group.

TH commented on the importance of having an appropriate scope for this effort. This might differentiate our effort from that of CEDIA due to the professional nature of the products detailed in the current scope.

CH inquired of interest within the group to lead a smaller, more focused task group to further develop this proposed standard. There was no response from the group.

Our working group is encouraged to review this draft once it is available. Hopefully one or two champions for this proposal will come forward to lead the development effort. If not, it will be abandoned.

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.

CH mentioned that the originators of this proposal no longer seem to be active in our working group. He inquired if anyone was willing to step up to help lead this development effort. No voiced interest to undertake this.

DP commented that this effort might be better suited as an information document than a standard. He suggested that this project be withdrawn due to lack of progress. The working group withdrew this project by unanimous consent.


RC reported that we don’t currently have a formal liaison with CEDIA. DM is active is CEDIA and willing to serve as our liaison. He will attempt to get contact information for Walte Zerbe or other appropriate CEDIA member to act as CEDIA’s liaison with SC-04-03.

New Projects

RC mentioned the significant on-line correspondence that has recent occurred for this topic. He suggested that that this becomes a formal project. TH concurred with an appropriate scope so as to not be confused to be relevant or applicable to perceptual attributes. JH agreed.

A good discussion on the topic ensued. There was consensus that this would be an effort worth pursuing and that a formal project proposal for a standard be submitted.

JM mentioned that one to two people need to take the lead on this development effort to ensure that progress is maintained, similar to the way SC-04-03-A worked to develop AES75. GH added comments in agreement.

JH agreed to help complete the formal project proposal and scope with the assistance of RC.

CH committed to email the working group to inform them that a task group is being formed to pursue this development effort and attempt to gain engagement from those that are interested in assisting with the work.

New Business

The next meeting will be held online in May 2024, scheduled in conjunction with the AES 156th Convention.

AES - Audio Engineering Society