EN
VENTED ENCLOSURES
A vented enclosure acts like a sealed enclosure at frequencies
above its tuned (resonance) frequency. At resonance (which is
defined by the vent), the vent produces the majority of sound- the
subwoofer cone is nearly stationary while the air inside the vent
vibrates. This provides greater mechanical power handling at and
above resonance, but reduced mechanical power handling below
resonance. Since the subwoofer cone and voice coil do not move
much at resonance, airflow across the voice coil is minimized and
thermal power handling is reduced slightly at resonance.
Vented enclosures provide better efficiency in the 40Hz – 60Hz
range, at the expense of sound output in the lowest octave (below
40Hz). The use of an infrasonic filter is recommended with vented
enclosures. An optimum vented enclosure for a Series subwoofer
is larger than an optimum sealed enclosure.
VENTED-ENCLOSURE
PERFORMANCE ADVANTAGES
• An optimum vented enclosure has greater efficiency and higher
output in the 40Hz – 60Hz range than an optimum sealed
enclosure.
• An optimum vented enclosure provides a greater sensation of
bass than an optimum sealed enclosure.
• A subwoofer in an optimum vented enclosure will require less
amplifier power to achieve a given acoustic output (down to
the enclosure's resonance frequency) than in an optimum
sealed enclosure.
VENTED-ENCLOSURE
PERFORMANCE TRADE-OFFS
• Reduced output in the lowest octave (below 40Hz).
• Reduced mechanical power handling below the enclosure's
resonance frequency. The use of an electronic infrasonic filter is
strongly recommended to reduce the chance of overdriving the
subwoofer below the enclosure's resonance frequency.
• An optimum vented enclosure will always be larger than an
optimum sealed enclosure.
VENTED-ENCLOSURE
CONSTRUCTION
Vented-enclosure construction is more difficult than the
construction of a sealed enclosure. The enclosure volume and
port dimensions have a specific relationship with the physical and
electromechanical characteristics of the subwoofer, requiring that
the recommended enclosure volume and port characteristics be
strictly observed. As with sealed enclosures, use medium-density
fiberboard (MDF), glue and screws to construct the enclosure, and
seal all joints with silicone caulk.
RECOMMENDATION
Subwoofers in vented enclosures are recommended for
enthusiasts who prefer accentuated bass response, for those who
have plenty of cargo space to devote to a subwoofer enclosure
and for those who will use a less powerful amplifier to drive their
subwoofer. The volume and port dimensions indicated must be
followed precisely to ensure optimum performance.
MOUNTING THE SUBWOOFER
The subwoofers should be mounted from the outside of the
enclosure. Use the included foam mounting gasket to ensure a
leak-free seal between the subwoofer frame and the enclosure.
CONNECTING THE AMPLIFIER
The subwoofer connectors are compatible with bare wire ends.
The recommended wire gauge is between 14AWG and 8AWG,
depending on the length of the wire run between the amplifier and
woofer. Heavier gauge wire is preferred for runs over 6' (2m).
To connect the speaker wire coming from your amplifier, push
down on the terminal to expose the connection hole. Thread
the bare wire end through the hole, then release the terminal to
secure. Be sure to observe proper wire polarity for maximum
performance.
TECHNICAL DATA
THIELE-SMALL PARAMETERS
SKUs
Arena 8 inch
Arena 10 inch
Arena 12 inch
SSI
2Ohm
SSI
4Ohm
SSI
2Ohm
SSI
4Ohm
SSI
2Ohm
SSI
4Ohm
Voice coil DC
resistance:
R
EVC
(OHMs)
1.81
3.52
2.14
4.23
2.16
4.26
Voice coil
inductance
@ 1kHz:
L
EVC
(mH)
0.666
0.213
1.254
0.589
1.265
0.621
Driver
radiating
area:
S
D
(IN
2
)
S
D
(CM
2
)
32.742
211.24
32.742
211.24
51.159
330.06
51.159
330.06
79.16
510.71
79.16
510.71
Motor force
factor:
BL (T
M
) 9.036
11.467
8.467
10.48
9.726
12.201
Compliance
Volume:
V
AS
(FT
3
)
V
AS
(Liters)
0.269
7.612
0.287
8.123
0.641
18.165
0.687
19.473
1.367
38.720
1.464
41.446
Suspension
compliance:
CMS
(mm/N)
0.121
0.129
0.118
0.126
0.105
0.112
Moving mass,
air load:
M
MS
(Grams)
97.652
92.094
182.757 172.795 249.048 235.676
Free-air
resonance:
F
S
(Hz)
46.4
46.2
34.3
34.1
31.1
30.9
Mechanical
Q:
Q
MS
13.157
4.019
9.827
5.631
11.669
5.914
Electrical Q:
Q
ES
0.635
0.716
1.175
1.412
1.108
1.311
Total Q:
Q
TS
0.601
0.608
1.049
1.129
1.012
1.073
Magnetic-
gap height:
H
AG
(IN)
H
AG
(mm)
0.315
8
0.315
8
0.315
8
0.315
8
0.394
10
0.394
10
Voice coil
height:
H
VC
(IN)
H
VC
(mm)
1.338
34
1.338
34
1.181
30
1.181
30
1.259
32
1.259
32
Maximum
excursion:
X
MAX
(IN)
X
MAX
(mm)
0.511
13
0.511
13
0.433
11
0.433
11
0.433
11
0.433
11
