Report of the SC-04-04 Working Group on Microphone Measurement and Characterization of the SC-04 Subcommittee on Acoustics meeting, held in conjunction with the AES 113th Convention in Los Angeles, CA, US, 2002-10-07

The meeting was convened by chair D Josephson.

The agenda and the minutes of the previous meeting were approved as written.

Open Projects

AES42-R, Review of AES42-2001: AES Standards for Acoustics -- Digital interface for microphones
The meeting of SC-04-04-D which had occurred on the previous day was discussed. There is nothing new to report; there are as yet few microphones with a digital interface and there is still some concern about the connector and cable to be used for interfacing to such microphones. There is some work going on in SC-04-04-D for a maintenance revision; the leader of that task group however was not present to comment.

The target date for the current goal of revision remains 2006.

AES-X62, Psychoacoustics of Microphone Characteristics
AES-X63, Time-Domain Response of Microphones
These two projects were, as usual, discussed jointly because many of the issues are shared between them. The discussion was led by vice chair J Green, who is also leader of the task group SC-04-04-B, which is working on the both projects. Several members commented on the lack of interest within their customers for additional microphone specifications, and the lack of resources within microphone manufacturers to offer such specifications. N Sobol and M Opitz suggested that the present microphone standards were probably sufficient at this point and that we should be content with IEC 60268-4. Jim Brown brought up comparisons with loudspeaker testing, where additional specification detail was found to be helpful. Both projects will be reviewed again at the next meeting.

AES-X85, Detailed Professional Microphone Specifications
J Brown reiterating the need for specifications on data sheets that had real meaning to the user. J Wuttke pointed out the need for diffuse field sound response to be reported if new metrics were to be added.

AES-X93, Recommendations for Revisions of IEC 61938 Clause 7
There was a brief discussion. There seems to be little support for either of the new phantom power variants that were proposed in the recommendation sent to IEC in 2000-12, and principally an interest in removing references to P24.

Review of this project will continue in 2003-03.

Liaison

The chair reported on the discussion that had taken place the day before at the Technical Committee on Microphones and Acoustics meeting, which was attended by a number of people from the user community. There had been some discussion about non-traditional microphone performance specifications, such as using audio recordings or alternate graphics.

New projects

No new projects were raised or introduced

New business

There was no new business.

The next meeting will be held in conjunction with the AES 114th Convention in Amsterdam, the Netherlands.