inches. Larger back volumes will increase the low-frequency
output. The frequency response of a 405 in a typical
0.5-cubic-foot back enclosure is shown in Figure 1.
Mounting
The 405 may be front or rear mounted against either surface
of its mounting flange and requires a 110-mm (4.35-in.)
diameter cutout and a 120-mm (4.72-in.) bolt circle, as shown
in Figure 7. Normal fasteners up to 5 mm (0.20 in.) will fit
through the four holes in the frame. The 405 is designed for
mounting on standard ceiling speaker baffles.
Dimensions
409 Theile-Small Parameters
Free Air Resonance, fs: ......................................................... 90 Hz
Equivalent Volume Compliance, Vas: .................................. 0.61 ft.
3
Total Q, Qts: ............................................................................. 1.54
Electrical Q, Qes: ..................................................................... 1.78
Mechanical Q, Qms: ............................................................... 11.53
Volume Displacement, VD ................................................... 1.95 in
3
Reference Efficiency: ............................................................ 0.71%
Recommended Connections
The 405-8H is a nominal 8-ohm impedance loudspeaker with
a 16-watt input capability. The 405-4T utilizes an 4-watt, 70.7-,
100-volt universal line-matching transformer with power taps
ranging from 1 to 4 watts.
Recommended Enclosures and Baffles
The 405-8H, 405-4T are designed to fit on standard 4-inch
ceiling speaker baffles. Additionally, these loudspeakers will
accommodate the use of any standard back enclosure with a
diameter of 5.5 inches or greater and a depth of at least 4.5
Transformer Specifications
Frequency Response:
15700
: .................................................... 100 Hz to 10 kHz, +/-1 dB
15704, 15708, 15716, 15732
: ................. 50 Hz to 15 kHz, +/-1 dB
Insertion Loss:
15700
: .................................................................................... 1.0 dB
15704, 15708, 15716, 15732
: ............................................... 0.5 dB
Secondary Impedance:
.......................................................... 8 ohms (all)
Primary Impedances and Power Drawn, nominal 70v:
0
0
7
5
1
4
0
7
5
1
8
0
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5
1
6
1
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4
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8
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3
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1
