Fostex FF225WK User Manual
Page 2
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1k
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64
4
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50k
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(dB)
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60°
100
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(dB)
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Hz
(dB)
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30°
60°
100
1k
10k
4
8
16
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2k
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50k
40
20
Hz
(dB)
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60
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100
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30°
60°
100
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10k
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(dB)
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I
RED MARKING
A
B
C
D
E
F
G
H
I
F
A
B
G
H
C
E
D
RED MARKING
ø
J
٘
٘
MODEL
A
B
C
D
E
F
G
H
I
J
Note
FF85WK
ø70
47.5
4-4 x 6**
ш86
ш65
43.3
3.4
15
ш73
FF105WK
ø92
54.6
4-5 x 6**
ш115
ш85
48.8
4
15
ш93
FF125WK
ш102.2
62.4
4-ш5*
ш126
ш90
57.5
3.8
15
ш104
FF165WK
ш143.6
78.5
4-ш5*
ш174
ш120
72
4.6
20
ш146
FF225WK
ш182
93.7
4-ш5*
ш220
ш145
86.5
5.2
18
ш185
40
50
60
70
80
90
100
110
dB
100
200
500
1k
2k
5k
10k
20k
50k
100k
Hz
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A double-layer cone paper consists of two layers. One is a basic layer and the other is a surface layer. In the FF-WK series, a long-fibered
(low freeness) wooden pulp is used for the basic layer, which has high rigidity realized by the large volume structure and appropriate
internal loss. For the surface layer, the bincho charcoal powder is blended with a short-fibered (high freeness) kenaf, which allows to
accelerate the propagation speed on the cone paper surface.
The up-roll edge shape realizes a long stroke. A polycarbonate series material which has opposite physicalities of high loss and high
Young’s modulus is specially blended with urethane foam.
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A ridge-dome shape center cap made of aluminum alloy is employed. Dispersing and deadening a resonance occurred at a specific
frequency with this cap helps to ease an unnecessary sound coloration at high frequency range. Also direct coupling with the voice coil
bobbin expands the high frequency response.
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3-point gluing which glues the cone paper, damper and the voice coil at one point is employed on the FF-WK series. Increasing the
strength of the cone neck section realizes an improved high frequency response. Employing the pocket shape at the damper neck section
has realized the 3-point gluing even with the usage of junction cable.
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In order to minimize the sound variation, the Faston 205 gold coating connection terminal is employed as a speaker terminal.
Main Features
The color tone of FF-WK series cone paper is created by the bincho charcoal and no dye is used. Due to this fact, there is a case that the color tone
slightly differs from each other.
FF-WK New Technology Elements
Surface Layer
(kenaf: about 2 mm of fiber length)
Basic Layer
(wooden pulp: about 4 mm of fiber length)
Surface Layer
0.697
3.608
2273
3.264
0.0258
Density (g/cm
3
)
Young’s modulus (Gpa)
Acoustic velocity (m/s)
Bending rigidity
Internal loss
Basic Layer
0.77
3.598
2158
2.8
0.0298
Pocket Neck Damper
(Shape Diagram)
Comparison on ridge / conventional dome vibration mode
Conventional dome diaphragm
shape and vibration mode
Ridge dome diaphragm
shape and vibration mode
Axis objective mode occurs.
Axis objective mode does not occur.
Comparison on ridge / conventional dome freq. response
Ridge dome
Conventional dome
Outer Shape / Baffle Hole Dimensions List
*: Circular hole, **: Slotted hole
FF85/105/125WK outer shape drawing
FF165/225WK outer shape drawing
Baffle hole drawing
Frequency Response
PLUS TERMINAL
PLUS TERMINAL
FF85WK
FF105WK
FF125WK
FF165WK
FF225WK
IMPEDANCE
IMPEDANCE
IMPEDANCE
IMPEDANCE
IMPEDANCE