Tyco 579-769 specifications Equation 2-11. Coverage Area Calculations

Determining Critical Polar Angle

Once the critical polar angle has been determined, calculate the coverage area for a given speaker- to-listener distance:

⎛ θ ⎞ Coverage Circle Diameter = 2 D2 tan ⎜ ⎟ ⎝ 2 ⎠

Coverage Area = π	⎛		⎛ θ		⎞⎞2
	⎜D	2	tan ⎜		⎟⎟
	⎜		⎝	2	⎟
	⎝				⎠⎠

Where D2 is the distance from the speaker to the

listener and θ is the critical polar angle. (Refer to Figure 2-5, Speaker Coverage Diagram)

Equation 2-11. Coverage Area Calculations

The following table contains coverage areas calculated for Simplex TrueAlert Ceiling Mount speakers at various ceiling heights with a listener height of 5 feet (1.5 meters).

Table 2-1. Simplex 4902 Speaker Coverage for Varying Ceiling Heights

Listener Height = 5 Feet

Ceiling	Coverage	Coverage
Height	Diameter	Area
8 ft	7.7 ft	46 ft2
10 ft	12.8 ft	129 ft2
12 ft	17.9 ft	252 ft2
14 ft	23.0 ft	417 ft2
16 ft	28.2 ft	623 ft2
18 ft	33.3 ft	870 ft2
20 ft	38.4 ft	1158 ft2

Listener Height = 1.5 Meters

Ceiling	Coverage	Coverage
Height	Diameter	Area
2.5 m	2.6 m	5.1 m2
3.0 m	3.8 m	11.6 m2
3.5 m	5.1 m	20.6 m2
4.0 m	6.4 m	32.2 m2
4.5 m	7.7 m	46.3 m2
5.0 m	9.0 m	63.0 m2
5.5 m	10.2 m	82.3 m2
6.0m	11.5 m	104.2 m2

Some observations about speaker coverage area:

•Low ceilings require more speakers per square foot of floor space than high ceilings.

•The Simplex 4902 series 4-inch speakers cover an area with a diameter slightly larger than twice the distance from the ear to the ceiling.

•The smaller the speaker, the wider the dispersion, therefore the larger the coverage area.

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