10
We provide Theile/Small Parameters for those interested in
studying subwoofers further. We do not recommend you use
computer software to determine enclosure sizes or type.
While high–end enclosure design software may be useful for
engineering purposes, it cannot completely predict perform-
ance in a given vehicle and should not replace a real enclosure
that has been tested and listened to in a car. Please use our
recommended enclosures for optimum performance.
Specifications
12.5LF
10.5LF
8.5LF
1500
Nominal Size
12" (30cm)
10" (25cm)
8" (20cm)
15" (38cm)
Mounting Cutout Diameter
11" (280mm)
9
1
⁄
8
" (232mm)
7
3
⁄
16
" (183mm)
13
7
⁄
8
" (353mm)
Mounting Depth—Front Mounted
5
5
⁄
8
" (143mm)
4
3
⁄
4
" (121mm)
4
1
⁄
16
" (104mm)
7
3
⁄
4
" (197mm)
Mounting Depth—Rear Mounted
6
3
⁄
8
" (162mm)
5" (127mm)
4
11
⁄
16
" (119mm)
8
1
⁄
4
" (210mm)
Recommended Amplifier Power
50–1200 watts
50–1100 watts
50–750 watts
50–1000 watts
Nominal Impedance
2
Ω
/4
Ω
2
Ω
/4
Ω
2
Ω
/4
Ω
2
Ω
/4
Ω
Theile/Small Parameters
12.5LF 12.5LF
10.5LF
10.5LF
8.5LF
8.5LF
1500
1500
(2
Ω
) (4
Ω
)
(2
Ω
)
(4
Ω
)
(2
Ω
)
(4
Ω
)
(2
Ω
)
(4
Ω
)
Resonant Frequency (F
s
)
30Hz
31Hz
33Hz
34Hz
35Hz
36Hz
34Hz
35Hz
Equivalent Volume (V
as
)
84 liters
84 liters
35 liters
35 liters
21 liters
21 liters
155 liters
155 liters
2.97ft
3
2.97ft
3
1.24ft
3
1.24ft
3
0.74ft
3
0.74ft
3
5.47ft
3
5.47ft
3
Total Q (Q
ts
)
0.45
0.57
0.44
0.53
0.33
0.40
0.72
0.85
Electrical Q (Q
es
)
0.47
0.61
0.47
0.57
0.35
0.42
0.81
0.97
Mechanical Q (Q
ms
)
9.8
9.6
8.0
7.8
9.0
9.0
8.3
8.3
Compliance (C
ms
)
230µm/N
230µm/N 255µm/N 255µm/N 330µm/N
330µm/N
142µm/N
142µm/N
Moving Mass (M
ms
)
121g
117g
90g
86g
63g
60g
148g
145g
Cone Area (S
d
)
510cm
2
510cm
2
315cm
2
315cm
2
215cm
2
215cm
2
876cm
2
876cm
2
Voice Coil Diameter
51mm
51mm
51mm
51mm
51mm
51mm
51mm
51mm
Voice Coil DCR (R
e
)
1.6
Ω
3.1
Ω
1.6
Ω
3.1
Ω
1.6
Ω
3.1
Ω
1.6
Ω
3.2
Ω
Voice Coil Inductance @ 1kHz (L
e
)
0.40mH
0.55mH
0.40mH
0.55mH
0.40mH
0.55mH
0.45mH
0.62mH
Linear Excursion—One Way (X
max
)
8.5mm
8.5mm
8.5mm
8.5mm
8.5mm
8.5mm
5.5mm
5.5mm
Peak-to-Peak Maximum Excursion
40mm
40mm
35mm
35mm
35mm
35mm
40mm
40mm
Reference Efficiency (
η
o
)
0.46
0.39
0.26
0.25
0.25
0.22
0.73
0.64
ProSeries
Competitor Series
ProSeries
Competitor Series