Re: 8-channel configuration


Subject: Re: 8-channel configuration
From: Richard Zvonar (zvonar@zvonar.com)
Date: Wed May 26 2004 - 15:50:39 EDT


At 10:01 AM -0400 5/26/04, Chin-Chin Chen wrote:

>I am wondering how many 8-channel configurations are currently used in
>concerts and what are the terms for each one.

More than you can shake a stick at :-)

However, the two most common are octagonal planar arrays - 8
equally-spaced speakers surrounding the audience (as used in Sound
Travels concerts) either in left-right pairs (Four Pairs
Configuration) or with center speakers (Double Diamond Configuration).

Another common configuration is a cubic configuration, with a lower
quad and an upper quad. http://www.stockhausen.org/octo.html

Sometimes the upper quad is oriented at 45 degrees to the lower.

There can be any number of other arrangements.

>```Are there standard numbering system to match the tracks on an ADAT to
>the speaker placement in a concert hall?

As you might expect, there is also more than one standard for channel
assignments. Here are a few:

Simple Left-Right

1 Left front
2 Right front
3 Left side-front
4 Right side-front
5 Left side-back
6 Right side-back
7 Left back
8 Right back

Based on SMPTE, Type A:

1 Left front
2 Right front
3 Center front
4 Center back
5 Left side
6 Right side
7 Left center
8 Right center

A "double quad" arrangement

1 Left front
2 Right front
3 Left back
4 Right back
5 Center front
6 Center back
7 Left side
8 Right side

Clockwise from front center

1 Center front
2 Right front
3 Right side
4 Right back
5 Center back
6 Left back
7 Left side
8 Left front

Each of these has its adherents. Perhaps other list members will
weigh in with their preferences. My personal preference is the first,
since my home studio is set up that way, but my impression is that
configurations with a center channel have the edge. SMPTE, Type A is
a 5.1 format with track 4 assigned to the LFE channel. I present a
somewhat arbitrary expansion of that. I suspect that what I'm calling
"double quad" may be one of the more common choices. The clockwise
arrangement was used by John Cage for Williams Mix.

Here are a few pertinent pages from the Sound Travels site:

http://www.soundtravels.ca/soundtravels/stfaq.html#wheresp

http://www.soundtravels.ca/soundtravels/difpract.html

http://www.soundtravels.ca/soundtravels/audcen.html

Other pertinent sites:

http://www.wendycarlos.com/surround/surround3.html#top

http://www.surroundassociates.com/fqmain.html

-- 

______________________________________________________________ Richard Zvonar, PhD (818) 788-2202 http://www.zvonar.com http://RZCybernetics.com



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