reported
by: Mr. Jibby Jacob
Secretary (Term
1997/98)
AES Singapore Section was treated
to an extremely interesting seminar on the evening of Monday, 27 October
1997 at the Ngee Ann Polytechnic - Department of Electrical Engineering's
staff conference room. It was interesting because it was presented by none
other than Professor Dr. Jörg Sennheiser from SENNHEISER Electronic GmbH &
Co. KG who spoke on the timely topic of microphones in this multimedia age.
In his clear and lucid style,
Sennheiser took the audience of about 45, including 10 members, from the
fundamentals of the Fletcher-Munson's curves and its implications to the
design of microphones.
Sennheiser reiterated that our
interpretation of an audio stimulus includes the total perception with all
the 5 senses plus the tactile sense taking part inter-dependently. In this
respect, the hearing response for the above is different for each individual
and the equal loudness curve represents an average for 50% of all human
beings with the threshold of hearing varying by at least ± 10% individually.
He then went on to describe the
ideal specification for the microphone design which includes smooth
frequency response, minimal internal noise & distortion along with immunity
to Electromagnetic interference. Using specification of microphones
manufactured in his company, Sennheiser explained the working principles of
the Dynamic microphones, AC Condenser & RF condenser microphones. Contrary
to expectation, he declared that harmonic distortion is a good thing in a
microphone in that it added colour to the sound quality that is much sought
by users.
|
Seated from
left-to-right are Mr. Stephen Low, AES Committee Member; Mr.Jibby Jacob,
AES Secretary; Dr. Roland Tan, AES Chairman; Mr. S.F. Ho, Director of
Sennheiser Electronic Asia Pte Ltd; Professor Dr. Jorge Sennheiser
(Speaker) and Chairman of the Board of Sennheiser Electric from Germany
with his daughter; Mr. Chiew Hai Kong, General Manager of O'Connor's
Singapore Pte Ltd; and Ms. Karen Chan, Reporter from Raffles Trade Press
Pte Ltd. |
As an aside, he then went on to
explain how important active noise cancelling microphones, which have an
improvement of about 15 to 20 dB S/N above the normal microphone, are to
airlines for the communication between pilot and air traffic control.
|
Dr. Roland Tan,
Chairman AES Singapore Section (left), presenting the token of
appreciation to the seminar speaker for the evening, Professor Dr. Jorg
Sennheiser, Chairman of the Board of Sennheiser Electronic, Germany
(right). |
He concluded that as media
turns digital with CDs, DATs, DVD & DAB, the highest quality microphones
must be used to capture audio with the highest fidelity for distribution
to the listener.
At the end of an hour and
fifteen minutes of lecture, Sennheiser invited questions. One question
included development of digital microphones. Sennheiser revealed that
his company designed them in 1992 based on the AES/EBU standards;
however their performance was inferior to their analogue equivalent. The
shelf life of microphones was another concern that the audience
expressed. Other questions concerned the use of titanium capsule in
microphone design and subjective measurements of microphones that should
last at least 30 years under normal wear and tear conditions. |
At the end of the seminar, to the
surprise and delight of the audience, each guest was given a pair of the
famous SENNHEISER Headphones HD 414, courtesy of SENNHEISER Electronics Asia
Pte Ltd, without whom this seminar would not have been possible. AES
Singapore Section would also like to thank the Ngee Ann Polytechnic for
providing the venue for this excellent seminar. |
