Room Layout and Component Placement – Speaker Locations
At this stage in the planning process you should have your room dimensions, main seating area, video display screen size, and projector location (if you are using a projector) defined.  You should also have a good idea of the speaker configuration you plan to use (5.1, 7.2, etc).  Now let’s look at where all those speakers should be located for optimum results.  The two main criteria for locating speakers are the angle and distance from the central listening location in the middle of the main seating area (the sweet spot).  The final location of speakers relative to the main seating area will signficantly affect sound quality.

Speaker Installation Notes:
•    A good starting point is divide the room into a grid of thirds or fifths and locate speakers along these guidelines.
•    The center channel speaker should be centered on the display screen, directly in front of the main seating area (0°) away from the front wall and slightly in front of the display screen.
•    The front left and right main speakers should be located on either side of the display screen at least 22° but not more than 30° from centerline and away from the front and side walls if possible.
•    Position speakers so the drivers are aligned vertically (except for the center channel)
•    The distance from the central main seating location to the front left, right, and center channel speakers should be the same.
•    In most cases (but not all) angle the front left and right speakers in slightly so they face the main seating area.
•    Ideally, all of the tweeters in the front left, right, and center channel speakers should be at the same height (listeners’ ears when seated).  Unfortunately this is not always possible as the center channel may have to be lowered to fit under the screen.  In this case angle the center channel speaker up slightly so it faces the listeners’ ears when seated.
•    The left and right surround channel speakers should be located between 90° and 110° from centerline. For movies, the surrounds should be elevated approximately 2′ or more above ear height.  For SACD and DVD-Audio they should be positioned at the same height as the listeners’ ears when seated.
•    The distance from the back surround speakers to the central seating location should be at least 5′ and ideally the same distance as to the front speakers if possible.
•    When using only one back surround speaker it should be located directly behind the main seating area (180°) and at the same height as the left and right surrounds.
•    When using two back surround speakers they should be located between 10° and 45° (30° for Dolby TrueHD and DTS-HD Master Audio) from the back centerline and at the same height as the left and right surrounds.

Note: These are guidelines to help you determine a good starting location for your speakers.  Fine tuning of speaker placement will be necessary during calibration and extended listening to determine the optimum location.

5.1 Surround Sound Speaker Locations

A basic 5.1 surround sound system incorporates five directional channels and one non-directional, low frequency effect (LFE) or subwoofer channel.  This is the minimum speaker configuration that is considered acceptable to reproduce an immersive sound stage and the vast majority of movies are encoded in Dolby 5.1 surround sound.  This configuration is ideal for small to medium size rooms, especially if you are on a tight budget. 

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(5.1 Surround Sound Configuration)

7.2 Surround Sound Speaker Locations

For larger rooms, adding two rear surround speakers creates a 7.1 channel configuration (6.1 if only one rear surround speaker is used).  One or two speakers located behind the main seating area can add depth to the sound stage.  But you should keep in mind that the majority of movie soundtracks and multi-channel audio (SACD and DVD-Audio) are still mixed in 5.1 channels; meaning the back surround channels must be artificially created (digital sound processor and algorithms from Dolby, DTS and Audyssey).  However, in the future expect to see an increasing number of Blu-ray DVDs and games being mixed in 6.1 and 7.1 channel audio.

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(7.2 Surround Sound Configuration)

Subwoofer Placement

It sometimes seems that subwoofer placement is more of an art than a science.  As we discussed previously, a properly sized room that minimizes standing waves is the place to start in optimizing subwoofer placement.  Incorporating two (or more) subwoofers into your home theater can offer significant advantages over having just one.  It’s not just about generating loud bass; but more importantly about generating clean, strong bass that delivers smooth bass response across the entire listening area.  Having two or more subwoofers can make placement much easier and can go a long way in helping to eliminate boominess and increase dynamic range.  Here are several examples of GOOD subwoofer placement, but in the end a little trial and error testing will help define the optimum location(s).

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