P81543 G
Sheet 2 of 5
Table 1 shows the sound pressure level performance of the MTH-24, and Table 2 provides a guide to horn spacing, area coverage,
and sound pressure level.
Table 1: Sound Pressure Level Performance
Sound Pressure Level (dB at 24 VDC)
Feet On
Axis
Full Power
(10 W)
1/2 Power
(5W)
1/4 Power
(2.5W)
4
115
112
109
8
109
106
103
16
103
100
97
32
97
94
91
64
91
88
85
128
85
82
79
Table 2: Horn Guide
Full Power (10W)
Half Power (5W)
Quarter Power (2.5W)
Noise
Level
*Spacing
& Distance **SPL Area
*Spacing
& Distance **SPL Area
*Spacing
& Distance
**SPL Area
Quiet
50-65dB
N/A
N/A
N/A
120 Ft.
83dB
14,400 Sq. Ft.
120 Ft.
80dB
14,400 Sq. Ft.
Moderate
65-75dB
110 Ft.
88dB
12,100 Sq. Ft.
110 Ft.
85dB
12,100 Sq. Ft.
110 Ft.
82dB
12,100 Sq. Ft.
90 Ft.
89dB
8,100 Sq. Ft.
90 Ft.
86dB
8,100 Sq. Ft.
90 Ft.
83dB
8,100 Sq. Ft.
Noisy
75-85dB
60 Ft.
92dB
3,600 Sq. Ft.
60 Ft.
89dB
3,600 Sq. Ft.
60 Ft.
86dB
3,600 Sq. Ft.
30 Ft.
98dB
900 Sq. Ft.
30 Ft.
95dB
900 Sq. Ft.
30 Ft.
92dB
900 Sq. Ft.
25 Ft.
100dB
600 Sq. Ft.
25 Ft.
97dB
600 Sq. Ft.
25 Ft
94dB
600 Sq. Ft
Very Noisy
85-95dB
16 Ft.
103dB
250 Sq. Ft.
16 Ft.
100dB
250 Sq. Ft.
16 Ft.
97dB
250 Sq. Ft.
*
Spacing between horns (side-to-side), and distance in front of horn at which a clear audible tone will be heard.
** Horn sound pressure level (SPL) should exceed the locations noise level by
at least
6dB.
SPECIFICATIONS:
Table 3.
Nominal Input Voltage
24VDC
Input Voltage Range
21.6VDC TO 26.4VDC
Input Current at 24VDC with Maximum Volume
0.6A
Sound Pressure Level (On Axis at 24VDC at Full Rated Output)
117dB at 1 Meter
Contact Closure Current Requirement
0.01A
Amplifier Rated Power Output
10 Watts
Speaker Voice Coil Impedance
8 Ohms
Tone Appliances
Warble and Single Tone
Operating Duty Cycle
See Table 4 and Notes
Table 4: Operating Duty Cycle
Contact Closure Duty Cycle
Warble Tone
Priority Tone
Continuous
(Minimum 5 Seconds On)
1 Second On
7 Seconds Off
Follows Contact Closure
(Takes Priority Over Warble Tone)
Interrupted
Follows Contact Closure
(See Notes Below)
Follows Contact Closure
(Takes Priority Over Warble Tone)
NOTES:
1) A continuous closure duty cycle is defined as having a minimum "On" time of 5 seconds.
2) Maximum warble tone "on" time, during any "On-Off" cycle, is 1 second. For interrupted contact closure duty cycles, warble
tone will operate as follows:
Table 5.
Interrupted Closure Duty Cycle "On" Time
Warble Tone Operation
1 second
Follows closure
Less than 1 second
Follows closure
More than 1 second (and less than 5 seconds)
1 second on
