Audio Engineering Society

Chicago Section

Meeting Review, October 12, 2004

10/12/04 Meeting Highlights
by Jeff Segota

On October 12th, the Chicago Section was treated to a �How To� Surround Workshop by recording engineer and author Mike Sokol, by invitation from S. Benjamin Kanters - Director, Audio Technology Center of Columbia College in Chicago. The Audio Arts & Acoustics Department of Columbia College hosted the meeting in their Live Sound Lab. About sixty people were in attendance, including many students. Numerous topics relating to recording, mixing and reproduction of music in surround were discussed.

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There is a large potential demand for music in surround because there is already an estimated 30 million systems in homes, and it is very easy to tell the difference between surround versus stereo. With surround, the listener�s perspective can be enhanced by placing him/her in the crowd of a concert hall, close to the performance in an intimate club, or right in the middle of the talent. These concepts were demonstrated with several audio samples.

Some options for center channel usage were presented, such as lead vocal, special instruments or effects, and split stereo where the front left and center are used for one stereo image and the center and front right are used for another stereo image. Another option is minimal center usage and creating a phantom center image with the front left

and right speakers. However, the audience was warned that if the center channel is left out completely, customers will complain. For the rear channels, some options are stabs and accents / alternate percussion, hall ambience or crowds and back wall reflections, alternate voices and effects, and electronically generated reverberation and room simulation. Again, all of the above concepts were demonstrated with audio samples.

Regarding microphone techniques, there are some surround microphones available, or an array can be configured from conventional microphones in a �5.0 tree� arrangement. Also, Mr. Sokol presented the FLuRB array, were four coincident cardioid microphones are configured and mixed in various ways to provide the five channels. Another option is to mix spot microphones for the front channels and use a distant stereo or binaural microphone for the rear channels.

Other topics included subwoofer channel usage, bass management, downmixing to stereo, beyond 5.1 (6.1, 7.1, and 8.0), alternative rear speaker options, system setup and calibration, workstation mixing, distribution media, codecs, broadcasting in surround, powerpoint surround, and sound effects. The audience was exposed to a wealth of information, presented by Mr. Sokol with energy and enthusiasm.