Meeting Topic: Audio 101 - An Introduction to Microphone Theory and Applications
Moderator Name: Mark Edwards
Speaker Name: Dr Rodney Staples
Other business or activities at the meeting:
The August meeting was the Annual General Meeting of the AES Melbourne Section, where the membership heard the Chairman's and Treasurer's reports, and elected the Committee for the next year. This year Greg Segal chose not to re-nominate for election to the Committee, and the meeting thanked him for his service.
The newly-elected Committee is:
Chair - Mark Edwards
Secretary - Peter Smerdon
Treasurer - Graham Haynes
Vice Chair - Graeme Huon
We welcome Julian Driscoll to the Committee, and thank him for his interest in serving the Section in this way.
Meeting Location: Swinburne Uni, Hawthorne, Vic
Following the AGM Dr Rodney Staples presented an introductory lecture on microphones.
Covering a wide range of microphone types and characteristics, Rod took us through the theory of operation and use of all the classic types of microphones.
Pressure vs Velocity types were explained - with dynamic, condenser, electret, and ribbon types being covered. There was even a short diversion into the original carbon microphones.
Directivity characteristics of various types were discussed - omni, cardiod, hypercardiod, and bipolar (figure8), and the proximity effect phenomenon was introduced.
The methods of generating various polar patterns were then presented, including the interference tube technique of the "shotgun" mics.
The theory of the boundary or pressure zone microphone was also outlined, together with examples of its application.
The topic of microphone arrays for stereo and multichannel pickup was covered, with examples of AB, ABC (Decca Tree), ORTF, Blumlein, XY, MS and Soundfield presented.
New developments in mic design were then discussed - like the miniature MEMS microphones used in personal audio devices like smartphones, and the non-diaphragm Microflown AVISA acoustic sensing device and its non-traditional application in acoustic location.
Overall Rodney gave us an exhaustive overview of microphone theory and applications, and it would be difficult to imagine anyone leaving the meeting without having learned something new about the subject.
Written By: Peter Smerdon