4
SELECTING AN ENCLOSURE
There are several different enclosure designs for different applications.
The SPL subwoofers work very well in all of the following enclosure
designs. It is up to you to select the specific enclosure that will work
the best for your particular application.
Infinite Baffle
Infinite baffle is the simplest type of subwoofer installation. In this type
of installation, the woofer(s) is mounted to a baffle which is then
mounted to either the rear deck or back seat of the vehicle. The best
results are achieved when the trunk area is virtually airtight and
isolated from the passenger compartment.
Sealed Enclosure
Sealed enclosures are relatively simple to build and install, as all that is
required is an airtight box. The larger the sealed enclosure, the more
the performance resembles that of an infinite baffle installation.
Vented Enclosure
Vented enclosures use a sealed enclosure with a vent or port in the box
which is tuned to resonate at a specific frequency.
Pros
Cons
•
Good low frequency exten-
sion down to the tuning fre-
quency
•
High power handling down
to the tuning frequency
•
Higher output than sealed
enclosures
•
Low power handling
below the tuning fre-
quency
•
Almost no output be-
low the tuning fre-
quency
Pros
Cons
•
Very good low frequency ex-
tension
•
Very good transient re-
sponse
•
High power handling
•
Medium efficiency
Pros
Cons
•
Excellent low frequency extension
•
Excellent transient response
•
Uses almost no trunk space
•
Lower power handling
•
Low to medium efficiency
Vented (V)
Sealed (S)
9
Sealed Bandpass
(SBP)
Sealed (S)
Sealed Bandpass
•
Rear = 1.5 ft
3
sealed
•
Front = .75 ft
3
@ 48
Hz (4" x 13" port) -
High output with
good low frequency
extension. Good for
Rock or Rap.
•
Rear = .5 ft
3
sealed
•
Front = .75 ft
3
@
66Hz (4" x 5.25"
port) - Very high
output. Great for
Rap music.
50
55
60
65
70
75
80
85
90
95
100
10
100
1000
Frequency Hz
dB
50
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105
10
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1000
Frequency Hz
dB
Infinite Baffle
•
Excellent performance for all types of music at moderate levels.
Sealed
•
.5 ft
3
- Good linear
response, excellent
small enclosure.
Excellent for high
SPL, multiple driver
applications.
•
1.0 ft
3
- Good linear
response, excellent
all around enclosure.
Vented
•
1.5 ft
3
@ 33Hz (4" x
14" port) - Deep
bass, flat response.
Good small
enclosure.
50
55
60
65
70
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80
85
90
95
100
10
100
1000
Frequency Hz
dB
50
55
60
65
70
75
80
85
90
95
100
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100
1000
Frequency Hz
dB
Vented (V)
50
55
60
65
70
75
80
85
90
95
100
105
10
100
1000
Frequency Hz
dB
