with power-on visual indicator. Power amplifier shall employ only solid
state devices. Performance characteristics:
a.
Power output:
[_____] watts or greater
b.
Signal-to-noise ratio:
60 dB or greater at rated output
c.
Frequency response ratio:
Plus or minus 3 dB from 100 Hz 10,000 Hz
d.
Total harmonic distortion:
Less than 3 percent at rated output
e.
120 Vac, 60 Hz
2.1.4.3
Cone Speaker
Provide [ceiling] [wall] [pendant]-mounted cone type speakers. Include
rust-proof back boxes of acoustically damped construction, minimum 20 gage
steel or aluminum; provide for relief of back pressure. Include suitable
recessed mounted speaker grille, made of 20 gage minimum steel or aluminum.
Speaker assembly shall as a minimum conform to the following
specifications:
a.
Sensitivity (sound pressure level): Minimum of 92 dB, measured at
1 watt input, 1200 mm 4 feet on axis
b.
Frequency response ratio:
Plus or minus 3 dB from 80 Hz to 12,000
Hz
c.
Dispersion angle:
1.57 rad
90 degrees
d.
Transformer with 4 level taps:
[1/4] [1/2] [1] [2] [5] [10] [15]
[_____] watts
e.
Voice coils:
25 mm
one inch
2.1.4.4
Horn-Type Loudspeakers
**************************************************************************
NOTE: Ensure mounting height is indicated on the
drawings.
**************************************************************************
Horn-type loudspeakers shall be provided with line transformers, mounting
brackets and all hardware, shall be mounted at heights indicated on
drawings, and shall as a minimum conform to the following specifications:
a.
Power rating:
[15] [20] watts
b.
Frequency response ratio:
Plus or minus 3 dB from 250 Hz to
10,000 Hz
c.
Horizontal dispersion angle:
[one] [1.57] [2] [_____] rad
[57]
[90] [115] [_____] degrees
d.
Vertical dispersion angle:
[one] [1.57] [2] [_____] rad
[57]
[90] [115] [_____] degrees
e.
Sensitivity (sound pressure level): Minimum of 97 dB measured at
1 watt input, 1200 mm 4 feet on axis
SECTION 16822N
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