Crestron
Surround Sound
Primer
Many cabinets also have a door covering the speaker. The interaction
with this can have an adverse effect on the sound. Ensure that no part of
the door covers the speaker drivers. Try to keep the door from covering
the whole face of the speaker cabinet. This is not always possible,
however if you have the opportunity to influence the design of the
cabinet door, you could achieve better results. An important part of
cabinet design is the choice of covering of the speaker opening. Do not
use just any fabric. Use a fabric produced by an acoustics company.
Companies that manufacture acoustic fabric have different styles and
designs available that can appear like wood or have a unique pattern
that can add style to the theater enclosure.
Stereo Imaging
Begin by playing pink noise through both speakers. The stereo image
should be floating between the two speakers. While moving forward
and back, the image should stay centered. While moving left and right,
the image should move left and right correspondingly.
When listening to stereo music, an image between the two speakers
should be audible. In most recordings, the vocalist is centered while the
band is arrayed across the front soundstage. While moving left and
right, the image should move left and right correspondingly. Use
several different selections to perform this test. Selections are mixed
with different interpretations of the sound engineer image design.
If the image is not as tight as desired, the absorption methods for wall
reflections will help greatly. If a little more spaciousness is desired,
allow for reflections and you can even add diffusers to help create the
desired sound. Doing either of these is fine as long as the stereo image
is not adversely affected. No matter what your preference, you always
want to maintain a good stereo image.
Absorption and reflection can be added to any wall. Make sure it is
used in the proper location for the desired room response. You do not
want a heavy reflection off the back wall sitting right against it (like
many seats in a home theater). Instead, add a little absorption directly
behind the listener and diffusion to the sides. This can reduce the
unwanted reflection that can ruin the stereo image while still providing
a feeling of spaciousness.
A diffuser is a device that takes any incident sound and directs it in
different directions. Some sounds return to the listener, while others do
not. You can purchase diffusers from some of the acoustics companies
or you can use things in the room such as bookcases, paintings,
sculpture and other furniture that has surfaces of varying depths.
About Surround Sound
The same theories are applied to surround speakers as stereo speakers.
Placement should be about six feet above the finished floor, and should
present a stereo image in their placement around the room. For
instance, if a plane rumbles directly overhead, you should hear the
sound travel evenly from front to back. A single pair of surrounds
should be placed slightly behind the main seating position. If you have
additional rears they should be placed on the back wall, positioned
between the front right and left speakers and directed toward the front
Primer – DOC. 6122
Surround Sound
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