The amazing images presented by today's high-definition video displays often overshadow the emotional impact of the audio half of the equation. A carefully chosen and installed surround sound system is critical to get the most out of the soundtrack. The center, mains, surrounds and subwoofer work as a collective whole, placing you in an immersive environment. Even in oddly shaped rooms, sonic nirvana is achievable.
Fronts and Center
Place the center channel speaker immediately above or below the television or screen. The close proximity to the screen anchors dialogue and on-screen effects sent to the center speaker to the display.
Place the left and right main speakers to the left and right of the screen. Locate the speakers so the distance from them to the main listening position is as close as possible to their distance from one another. Angle the speakers at a 30-degree angle relative to your primary seating position. If you're seated in this position and all you can see are the speakers' grilles as they face you, you have the right angle.
Place height channel or front effects speakers high and to the outside of the front main speakers. These can be smaller speakers than the mains, designed to provide enhanced immersion.
Set dipole surround speakers directly parallel to and 18 inches above the main listening position or row. Dipole speakers have drivers on both ends of the cabinet, simulating a large array of conventional speakers.
Set bipole speakers in the same area as dipole designs. Each driver array on the speaker cabinet is in-phase, providing better bass response than their dipole cousins. As a result, placing the speakers slightly behind the primary listening position will not be detrimental as it would be with dipoles.
Set direct-radiating surrounds to the side of the primary listening position in a 7.1 array. In a 5.1 setup, place them to the side and slightly behind you at a 110-degree angle. Speaker height should be the same as the front main and center speakers.
Locate surround back speakers in a 7.1 system behind the seats, between 130 and 150 degrees relative to you. THX Labs recommends setting these rear surrounds close to one another, centered in the back of the room. Select this option if your receiver or processor uses THX processing.
Spot your Sub
Connect your subwoofer to your receiver's "SUB" output, using an RCA cable long enough to reach your seating position. Plug the other end into the "LFE" jack on the sub. Plug the sub into AC power, using an extension cord if necessary.
Begin playback of bass-heavy musical or movie content. Crawl around the perimeter of the room, finding the spot where the bass sounds deep and tight. Mark this spot with a piece of painter's tape.
Relocate the subwoofer to the marked location. When you are seated in your main listening spot, you will have the same bass you found crawling around the room.
Dialing It In
Screw the calibration microphone included with your receiver to the camera tripod. Set the tripod and microphone on your main seating position at ear level.
Press the "Menu" button the receiver's remote control. Locate the "Auto Setup" or similarly-named option in your receiver's menu.
Begin the auto-calibration setup. Allow the chirps to play from each speaker. These chirps provide the system the data needed to produce correct distance, level and equalization adjustments.
Examine the auto-calibration settings. Change any speakers set to "Large" size to "Small." This redirects low frequencies to the subwoofer, increasing clarity and performance.
- If your room is oddly shaped, use speaker stands to place your surrounds around your seating positions. This allows you to place the speakers as recommended, bypassing constraints provided by asymmetrical walls. You can also use in-ceiling surround speakers to get them out of potential traffic areas in these environments.
- Acoustically transparent projection screens allow you to place the left, center and right speakers directly behind the screen.
- Tape a laser pointer on top of each speaker to point them directly at the sweet spot.
- RCA cable
- Extension cord
- Bass-heavy music or movie
- Painter's tape
- Camera tripod
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