reported
by: Christopher K C Yap
Secretary (Term
1999/2000)
On Friday, 12 May 2000 at
7.00pm, 15 members and 28 guests of the AES Singapore
Section gathered at the Touch Community Theatre to attend a talk on
“A DTV MultiChannel Audio Overview: Production, Distribution & Emission” by
Mr Gene Radzik, Audio
Applications Engineer from Dolby Laboratories
Inc, USA.
Radzik talked about the
evolution of audio first from mono to stereo, then from stereo to 4 channel
surround, then recently to 5.1 channel surround. He described the Dolby
Surround encoding system, where the centre and surround channels were
encoded into the left and right channel signals to form the LT (left total)
and the RT (right total) signals. Radzik also described how Dolby
Surround Pro-Logic Decoding utilised amplitude and phase relationship
information to decode the LT and RT signals into essentially 4-channel
surround. He related the fact that this matrix surround technology, known as
Dolby Surround, is presently widely adopted by many mediums, from broadcast
TV to cable to VHS to CD to CD-ROMs, and has sold more than 40 million
worldwide.
On the present conversion to DTV,
Radzik noted that increasing the number of channels basically adds to
the equipment requirements of a production facility. Firstly, there is now a
need for analog to digital conversion, and adopting multichannels in a
system translates to more routers, more speakers, more mixers, more
recorders, and so on. Radzik pointed out that going digital has its
advantages, one main one being increased signal flexibility.
| Digital signal
distribution can potentially maintain its quality, and the ability to
store metadata in digital signals provides a means to store peripheral
information useful for both the consumer and also during production.
Radzik mentioned that audio production tools will have to
incorporate multichannel routing, panning and monitoring for proper
multichannel production. |
Mr. Gene Radzik
discussing Dolby Digital (AC-3) multichannel audio with the local
audience. Dolby Digital is adopted by the ATSC standard committee in
the U.S. for DTV transmission as well as in Singapore, which has adopted
the European DVB standard photograph by
Robert Soo. |
Radzik said that the tasks
of meeting up to these challenges lie with the audio industry and bodies.
Professional organisations like the AES, ATSC, DVB, ITU, SMPTE, lay down
standards and recommendations as a guide for the entire industry. One
example he cited is the SMPTE recommendation for channel assignments and
levels. Recommendations also provide a guide for the post production
environment, such as speaker placements, and the equalisation of rooms.
Chairman, Mr.
Jibby Jacob, presenting the plaque to Mr. Gene Radzik after the talk
- photograph by Robert Soo. |
Introducing the
term “metadata”, Radzik placed much emphasis on the usefulness of
metadata, and said that its use will be increasingly common. He
mentioned that metadata could be used for consumer information, with
some parameters for DTV emission such as dialog normalisation, down
mixing, and dynamic range control. Professional metadata include
parameters used in production such as channel gain, metering, and
program configurations. |
At this point, Radzik did a
short demonstration of multichannel audio using DVDs. He noted that with
multichannel audio, listening positions in a typical stage performance can
take two perspectives. The audio can be produced in the normal perpective,
where the stage and artistes are in front of the audience, or the listener
can be in the midst of the band itself. Radzik went on to talk about
multichannel mixing techniques, and also the requirements of distribution of
multichannel audio.
|
Members and
guests of the AES Singapore Section at the Touch Community Theatre after
the talk on DTV Multichannel Audio. The speaker, Mr. Gene Radzik is
standing in front, 13th from right with a tie -
photograph by Robert Soo. |
The talk concluded with a short
Q&A session. The AES Singapore Section would like to thank Touch Technical
Services for the use of the theatre, and also their staff for the services
and support to the AES during this talk.
Biography of Mr. Gene Radzik
Mr. Gene Radzik
has been an audio production
specialist at Dolby Laboratories since
1996. Prior to joining Dolby, he worked on post production for television
and music production in Nashville and Chicago. Over the past 4 years he has
worked internationally on various projects including; internet audio, Dolby
Surround production support for television, DVD-Video release production
support (Tokyo, Miami, London, Los Angeles, Chicago, San Francisco), DTV
multichannel education and production support (Amsterdam, Singapore,
Taiwan), and multichannel audio production support for the
soon-to-be-released DVD-Audio format.
He is an
active member of the AES and SMPTE. Mr. Radzik received his B.S. in
Recording Engineering/Mass Communications from Middle Tennessee State
University. |
