Enclosures
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Prime R1 Subwoofer with Integrated Trim Ring
•
Mounting Screws
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Operation Manual
Recommended Enclosures
This manual outlines two specific types of enclosures that provide dis-
tinctly different performance. This section is to help you decide which type
is best for your application.
Sealed Enclosures
Sealed enclosures are the simplest to build. The most important part of
building a sealed enclosure is to make sure that the enclosure is airtight.
Using glue and some type of sealant on all seams will ensure solid con-
struction and prevent air leaks. The box volume will directly impact the
performance of the speaker. Larger enclosures will provide flatter response
and deeper bass where smaller boxes will provide a bump in the response
curve and generally higher output for greater SPL.
Advantages of sealed enclosures:
•
Small enclosures
•
Linear (Flat) response
•
No port noise
•
High power handling at all frequencies
•
Excellent for sound quality
•
Extended low frequency output when compared to vented enclosures
Vented Enclosures
Vented enclosures vary only from the sealed enclosure in that a vent or
port is added to "tune" the enclosure. The enclosures recommended are
designed for great overall performance. Larger boxes tend to be easy to
tune to lower frequencies while medium and small boxes are easier to tune
to higher frequencies. The vented design is less linear in response than
the sealed box but with noticeably more output at the tuning frequency.
Advantages of vented enclosures:
•
Higher average output than sealed
•
Tuning frequency can be easily adjusted by changing port length
•
Deep bass response with lower power requirements
•
Great for high output with limited power
Vented vs Sealed
The graph shown here is a sample of how the F3 drop-off point differs
between sealed and vented enclosures.
130.0
120.0
110.0
100.0
90.0
80.0
70.0
60.0
10.0
20.0
40.0
60.0
80.0
100.0
200.0
Sealed Box
Vented Box
Frequency, Hz
4
Building an Enclosure
To work properly, the walls of the enclosure must be rigid and not flex
when subjected to the high pressures generated by the speaker's opera-
tion. For optimum performance, we recommend using 3/4" MDF (Medium
Density Fiberboard) and internal bracing. The enclosure should be glued
together and secured with nails or screws.
Calculating Volume
Calculating volume is merely a matter of measuring the dimensions in
inches and using the formula: H x W x D divided by 1728 (cubic feet). See
block below.
Box Volume
Height" x Width" x Depth"
Divided by (cubic feet)
1728
If two facing sides are of uneven length, add them together and divide by
two to take the average. Using this number will give you the volume with-
out the necessity of calculating the box in sections and adding the sections
together. The thickness of the baffle material reduces the internal volume
so this must be subtracted from the outside dimensions to determine the
internal volume. The speaker itself also reduces the internal volume. The
amount of air displaced by each model is listed on the specification sheet
and should also be subtracted from the gross volume calculation.
Sealed Enclosures
NOTE: Vb is the gross volume, which is the TOTAL internal volume, be-
fore any speaker and/or port displacement. All external dimensions were
based on the use of 3/4" (1.90 cm) materials.
NOTE: When using enclosures other than recommended, call Technical
Support for correct application.
Optimum Sealed Enclosure Recommendation
Sealed Enclosures
R1S4-10
R1S4-12
V
- Internal Area cu. ft. (Liter)
0.59
1.02
b
(16.71)
(28.88)
F
- 3dB Point (Hz)
48
43
3
Qtc - Enclosure Damping
0.83
0.87
H - Height - inch (cm)
12.0
14.0
(30.48)
(35.56)
W - Weight - inch (cm)
14.0
18.0
(35.56)
(45.72)
D - Depth - inch (cm)
9.25
10.0
(23.50)
(25.40)
Recommended Sealed Enclosure Volum Range
Sealed Enclosures
R1S4-10
V
- Volume range cu. ft.
0.50 to 0.85
b
(Liter)
(14.16 to 24.07)
Vented Enclosures
NOTE: Vb is the gross volume, which is the TOTAL internal volume, be-
fore any speaker and/or port displacement. All external dimensions were
based on the use of 3/4" (1.90cm) materials.
NOTE: When using enclosures other than recommended, call Technical
Support for correct application.
Optimum Vented (Ported) Enclosure Sizes
Vented Enclosures
R1S4-10
V
- Internal Area cu. ft. (Liter)
1.4
b
(39.64)
F
- Tuning Frequency (Hz)
37.3
B
F
- 3dB Point (Hz)
32.0
3
H - Height - inch (cm)
12.0
(30.48)
W - Weight - inch (cm)
20.0
(50.80)
D - Depth - inch (cm)
14.0
(35.56)
P - Port Diameter and Length -
(1) 3 x 8
inch (cm)
(1) (7.62x20.32)
Autogoods "130"
Wiring Configurations
By varying the wiring configuration of your speakers you can create an
R1S4-12
impedance load to match your system. Altering the wiring configurations
gives a range of options for impedance loads. Series, Parallel, or Series-
0.7 to 1.8
Parallel wiring configurations are different techniques for wiring speakers
(19.82 to 50.97)
that provide different loads. Series configuration is a string method where
speakers are wired end to end. Parallel configuration uses two or more
speakers wired across common terminals. Series-Parallel configuration
combines both techniques. Choose the wiring diagram that corresponds
to the number of woofers and the impedance of your amplifier.
Subwoofer Crossovers
There are two operational types of crossovers, passive and active. Passive
crossovers (coils or inductors) are placed on the speaker leads between
the amplifier and speaker. An active crossover is an electronic filter that
separates the audio signal fed to different amplifiers. For optimum sub-
woofer performance, we recommend using an active 80-100Hz low-pass
crossover at 12dB/octave.
Parallel Wiring
R1S4-12
(2) 4 ohm SVC Speaker = 2 ohm Load
1.79
(50.69)
36.3
Series/Parallel Wiring
32.5
14.0
(35.56)
25.0
(63.50)
12.0
(30.48)
(1) 3 x 6
(1) (7.62x15.24)
(4) 4 ohm SVC Speaker = 4 ohm Load
Enclosures
5
