Apple Logic Pro 9 - Manual (Page 1182)

Positioning Your Speakers
The physical positioning of speakers is key to creating mixes that translate well to other
surround playback systems. As the 5.1 format is the most widely used, this section will
only cover 5.1 speaker placement. Much of this information can be applied to the other
formats.
Positioning the Front Speakers
The International Telecommunications Union (ITU) created a 5.1 definition that states
that the front speakers should be arranged left, center, and right, with the angle between
the left (or right) and center speakers being 30 degrees.
A narrower angle of 22.5 degrees has been suggested for use in cinematic systems to
comply with another requirement that the left and right speakers should be within four
degrees of the edge of the screen.
The ITU standard is primarily aimed at music-only systems, but you should consider using
the wider 30 degree angle, even if scoring for film. Use of this angle also allows stereo
signals to be auditioned correctly using just the left and right speakers, without resorting
to moving them around each time you switch between stereo and surround jobs in the
studio.
The three front speakers—left, center and right—should be placed in an arc (not a straight
line) at an equal distance from your listening position. In other words, the center speaker
should be set back slightly from an imaginary line drawn between the left and right
speakers. If this isn’t possible, ensure that you don’t place the center speaker closer to
the listening position than the left and right speakers.
If possible, your listening environment should also include a spot where the left and right
speakers are at an angle of 45 to 60 degrees from the ideal central “viewing” position.
An angle nearer to 45 degrees is preferred if watching movies, as it approximates the
circumstances in which film soundtracks are mixed and monitored. A wider angle, with
the left and right speakers farther apart, is recommended if you generally use your system
for listening to music, rather than watching movies.
This doesn’t have to be in the studio. If you’ve got a home theater setup, make your
surround mix in the studio, and listen to it/watch the DVD in your theater room (which
presumably has all speakers in “ideal” positions for film viewing).
The three front speakers should be as close as possible to the same height, at or near ear
level. Because it is often easiest to place the center speaker on top of the TV set at a fixed
height, consider mounting the left and right speakers on adjustable stands so that you
can match their height to that of the center speaker.
1182 Chapter 39 Working with Surround