Set up surround speakers for use in Logic Pro for Mac

Front speakers

The International Telecommunications Union (ITU) 5.1 surround definition states that 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 is suggested for use in cinematic systems where the left and right speakers should be within four degrees of the edge of the screen.

In the studio, you should use the wider 30-degree angle, even if scoring for film. Use of this angle allows stereo signals to be auditioned correctly using the left and right speakers, without moving them each time you switch between stereo and surround mixes.

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. The center speaker should be set back slightly from an imaginary line drawn between the left and right speakers. If this isn’t practical, don’t place the center speaker closer to the listening position than the left and right speakers. All three speakers should be at the same height—at ear level.

If possible, your listening environment should also include a position where the left and right speakers are at an angle of 45 to 60 degrees from the ideal central “viewing” position. An angle close to 45 degrees is preferred if watching movies, as it approximates the way film soundtracks are mixed and monitored. A wider angle, with the left and right speakers farther apart, is recommended if your system is principally used for listening to music, rather than watching movies.

It’s not essential to have a full surround setup in the studio. If you have a home theater system, make your surround mix in the studio, then listen to or watch it in your theater room.

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.

Overhead speakers

Overhead speakers (also called top or height speakers) are most commonly used in immersive audio systems to enable the overhead panning of sound objects and special effects. The number of overhead speaker channels is identified by the third digit in the format description. For example, in a 7.1.4 surround system, four channels are designated for overhead speakers.

You can use various configurations for these channels. For example, in a Dolby Atmos home theater system, upward-facing speakers, often incorporated into the front and rear surround speakers, are commonly used for the overhead speaker channels. The sound then reflects off the ceiling before it reaches the listener.

Discrete speakers are usually mounted on the ceiling, pointing downward. In systems with two overhead channels, the speakers are usually placed to the left and right of the listener. In systems with four overhead speakers, two are placed in the front above the left and right speakers, and two are placed in the rear above the left and right surround speakers. Speakers with a wide angle of dispersion provide the most coverage of the listening position.

LFE speaker

The LFE is a discrete effect channel for low frequencies (such as explosions, or 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.