User Manual

English • 7
PRO.BOSE.COM
Design Worksheet
C. The remaining loudspeakers are arranged on a square grid pattern using the LSD. If a loudspeaker would
be placed on or beyond the perimeter of the room, delete that row/column of loudspeakers.
Loudspeaker
Spacing
Loudspeaker
Spacing
D. After the last loudspeaker is placed, center the loudspeakers in that row to create new oset distances
out from each wall, which may be unique from ½ LSD.
E. (Optional) To quickly calculate the total Loudspeaker Quantity (LQ) needed to fill the rectangular room
without using graph paper, follow this method. In square layouts, the final total is sometimes slightly
reduced as you lay out rows. You can also determine final quantity by following Step B on graph paper
until the room is filled.
Loudspeaker
CA = Coverage Angle
–6 dB point (coverage edge)
Area = Square footage of room
(Length × Width)
Edge-to-edge =
LQ/4
–6 dB touching
Minimum overlap =
LQ/4
–3 dB touching
Center-to-center =
LQ/4
–1.5 dB touching
LQ =
Area
[(H – L)
M
2
—
]
2
Subwoofers: Quantity and Placement of Subwoofers
The number of subwoofers to use, where to position them, and how loud to set them can vary depending on
the individual situation. Details such as placement, boundary loading, room size, coupling quantity of multiple
loudspeakers to subwoofers, type of music, type of activity, budget, and the expectations of the listeners
should all be considered. The following guidelines are general rules to follow.
• Add one subwoofer for every group of four vocal- or full-range loudspeakers.
• Subwoofer spacing should be as far apart as is practical. 12.2 meters (40 feet) or greater subwoofer-to-
subwoofer spacing distance within the same zone is desirable.
• When the suggested subwoofer count is two within a single zone, it may be preferable to use either
one in a corner to avoid audible interference; or increase the count to three, which creates more
audible interference locations but limits them to smaller sizes where the reverberant field (added room
reflections) tends to mask them.
• Placing a ceiling subwoofer within 0.9 meters (3 feet) of a wall increases its output by 3 dB. Placing it
within 0.9 meters (3 feet) of a corner increases its output by another 3 dB (6 dB total) and also reduces
reflections that can create audible interference (bass cancellations) in the listening area.
• Listening positions located below the subwoofer should be supported by a nearby vocal- or full-range
loudspeaker to provide better tonal balance in the low-frequency pressure zone.