Apple Logic Pro X - Manual (Page 753)

Chapter 22 Surround in Logic Pro X 753
Surround speakers
The rear speakers (surround channels) should ideally be placed at the same distance from your
listening position as the front speakers, at an angle of 110 degrees from the front center speaker.
This angle is a compromise between producing an all-encompassing sound stage (at 90 degrees)
and the best rear-quadrant imaging (at 135 degrees).
The surround speakers should be placed alongside and slightly to the rear of (but not directly
behind) the listening position, well above ear level, to help minimize localization effects. They
should be aimed across the listening area, not directly at the listening position.
This positioning creates a broad surround sound field throughout the listening area,
approximating cinema speaker systems. If the speakers are placed too far forward, the rearward
effect will be insufficient. If the speakers are too far back, the surround information won’t be
integrated with the overall sound field. Experiment with placement and angles until the surround
sound field seems to encompass you, rather than come from behind you.
If your studio doesn’t have walls in the perfect place to mount surround speakers, try placing
them on stands above ear level. If you need to wall-mount the speakers, place them well above
ear level, and try aiming them at each other, toward the front, or to reflect off the side walls.
LFE speaker
The LFE is a discrete effect channel for low frequencies (explosions, avalanches) in film and
TV soundtracks. In surround music mixes, LFE is used as a low frequency channel for certain
instruments (bass drum or electric basses placed on the center with a frequency divider that
sends lower frequencies to the LFE speaker.
Bass frequencies travel much slower than higher frequencies, and are less directional. Ideally,
you should place the LFE speaker (often, a subwoofer) in a central position in front of the
listening position.