Proceed PDSD - Manual (Page 59)

59
System Planning Guide
Experience shows that almost any reasonable amount of time spent in the plan-
ning stages will pay for itself two to three times over during the installation—
more if the installation crew includes two or three people. With the background
provided in the previous sections, the planning process can be boiled down to a
checklist which will ensure that you do not overlook anything important.
video placement ■ The primary seating area should be perpendicular to the picture.
■ Be aware of the trade-off between screen size and perceived clar-
ity. The resolution of NTSC requires a seating distance of at least 4
times the diagonal screen size for maximum perceived clarity (this
is why small screens seem so sharp). Yet larger images have greater
visual impact. You may want to go for a seating distance of as little
as 2 times the screen size to increase visual involvement (although
this is probably only realistic if you have a line-doubled television).
■ Stray ambient light should be minimized. (Drapes, dimmers, light
placement)
■ Leave room for the Left, Center, and Right (LCR) speakers up front,
flanking the screen itself, placed with reasonable symmetry with
respect to adjacent walls, and all at the same distance from the pri-
mary viewing area.
■ The screen should be well away from side walls, since you want to
minimize side wall reflections from the front (LCR) speakers.
electronics placement ■ Cabinetry is generally preferred to conceal the distracting LEDs on
the equipment. (An infrared repeater system may be needed in
this case.)
■ The ideal system would have invisible, yet readily accessible equip-
ment and an IR repeater to relay the user’s commands from the
area of the screen to the concealed electronics.
■ People tend to aim their remote controls at the screen, regardless
of where the equipment is. In the absence of IR repeaters, placing
the electronics near the screen makes the system’s operation more
intuitive.
■ Ample ventilation for the power amplifiers must be provided, pref-
erably through convection (to avoid fan noise).
speaker placement ■ Can the speakers be used as designed? (Wall-mounting speakers
designed to be used in free space may create a mid-bass bump in
the response—consult with the manufacturer of your speakers as
to their best use.)
■ The Left and Right speakers often should be closer to the edges of
the screen than you may think best initially. There is some cogni-
tive dissonance (disorientation) when sound appears to come from
well away from its apparent visible source.
■ The Center speaker should be centered on the screen, directly
above or below it (unless you have an acoustically transparent
screen, in which case it may be directly behind the center of the
screen). Try to keep its tweeters as close to the level of the tweet-
ers in the L&R speakers as possible, so that pans do not involve
noticeable changes in altitude. Make sure that the Center speaker is