TOA bs-1030 Mode D'Emploi

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TOA Electronics Speaker Guide
 
Layout and Spacing for Distributed Speaker Systems
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Figure 6-1 Ceiling speaker coverage area
The speaker’s dispersion characteristics affect not only the required spacing and number of 
speakers, but also the overall sound quality and performance of the system. Large speaker 
cones (for example, an 8-inch full-range ceiling speaker) tend to produce narrow coverage angles 
in the high frequencies (called beaming), which cause dead spots between speakers unless they 
are spaced very closely together. Regardless of the speaker spacing, their overall diffuse-field 
output will still be lower in the high frequencies compared to their on-axis performance, leading 
to a dull sound in most of the listening area. TOA’s F Series wide dispersion ceiling speakers 
include features engineered to avoid this common problem, resulting in higher sound quality 
throughout the listening area.
Coverage Area and Ceiling Height
As the ceiling height increases, the area a speaker can cover increases, but the power required 
to reach the same volume at the listener’s position also increases. If the ceiling is very high (i.e., 
over 20 ft) some speakers may not be able to handle the power required for that distance. For 
ceiling heights greater than about 25 ft, consider alternatives such as mounting speakers on 
columns and walls, or suspending them below the ceiling, to get them closer to the listeners. 
Low ceilings are also challenging: for a ceiling lower than 12 ft, use a speaker with a coverage 
angle of 120° or greater.
Coverage Density vs. Budget
Once the coverage area per speaker is known, the next step is to decide how much overlap is 
needed between speakers. In distributed systems, higher density, or closer spacing of the 
speakers, provides more consistent coverage. If the speakers are spread too far, large portions 
of the listening area may suffer from inadequate volume and poor sound quality. The only 
downside of close spacing is cost. Balancing coverage density versus system cost is ultimately a 
subjective decision, but the information that follows can be a useful guide.
Ceiling
Coverage
angle
Floor
Speaker
Ceiling
height (h)
Ear
height (l)