Report of the Meeting of the SC-04-04 Working Group on Microphone Measurement and Characterization of the SC-04 Subcommittee on Acoustics held in New York, NY., US., 2011-10-22
The meeting was convened by chair D. Josephson.
The agenda and the report of the previous meeting, held in London 2011-05-15, were approved.
NOTE Unless stated otherwise, the status of open review projects is, "No action requested or required".
Open Projects
AES42-R: Review of AES42-2010: AES Standard for Acoustics - Digital interface for microphones
No action was requested or required
Development Projects
AES-X085 Detailed Professional Microphone Specifications
The chair gave a report on the progress of AES-X085. The noise source for the round-robin test has finally been located and the chair will endeavor to assure that tests are completed before the next meeting. There was some discussion of focusing AES-X085 efforts for the moment on giving guidance to the maintenance team for IEC 60268-4. Several members of the MT are also SC-04-04 members. The main issues remain a proper measurement of directional microphones used in entertainment applications, which are between "close talking" and "free field" in their operation. The chair will continue to summarize previous discussions in SC-04-04 for the IEC MT, including the work on directional patterns discussed on the reflector in 2010, and the consensus that an ITU standard "artificial mouth" be used for non plane-wave measurements. Performance measurements of vocal microphones at 2.5 cm and general purpose directional microphones at 20 cm are encouraged.
New projects
Frequency Response Data
A new project was briefly discussed, which is to summarize the "frequency response data" or FRD format that has evolved over the past decades for the description of transducer frequency response. A fairly clear summary of the two formats in use is available on the web but there are still some areas to be clarified. The chair will initiate a project request to AESSC to ask the appropriate WG to progress this into a standard.
New business
There was no new business.
The next face-to-face meeting will be scheduled in conjunction with the 132nd Convention of the AES in Budapest, 2012-04.
