Rockford Fosgate POWER T1 Serie Handbuch Seite 4

Enclosures
Carton Contents
• T1 Subwoofer with Trim Ring
• (12) Mounting Screws
• (4) Trim Ring Screws
• (1) Socket head driver bit
• Installation and Operation Manual
Recommended Enclosures
This manual outlines two specific types of enclosures that provide distinctly dif-
ferent 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 construction 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 frequen-
cies 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
Sealed Box Vented Box
4
Downloaded from www.Manualslib.com
40.0 60.0 80.0 100.0 200.0
Frequency, Hz
manuals search engine
Building an Enclosure
To work properly, the walls of the enclosure must be rigid and not flex when sub-
jected to the high pressures generated by the speaker's operation. 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
Divided by (cubic feet)
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 without 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 Enclosure
NOTE: Vb is the internal volume, before any speaker and/or port dis-
placement is added. 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.
W
Optimum Sealed Enclosure Recommendation
Sealed Enclosures
Total Internal Volume cu. ft. (Liter)
Woofer Displacement cu. ft. (Liter)
V - Internal Area cu. ft. (Liter)
b
F - 3dB Point (Hz)
3
Qtc - Enclosure Damping
H - Height - inch (cm)
W - Width - inch (cm)
D - Depth - inch (cm)
Recommended Sealed Enclosure Volume Range
Sealed Enclosures
V - Volume range cu. ft.
b
(Liter)
Height" x Width" x Depth"
1728
H
D
10" 12"
0.80 (22.62) 1.15 (32.56)
0.03 (0.82) 0.11 (3.11)
0.77 (21.8) 1.04 (29.45)
40.3 39.9
1.10 1.18
12 (30.48) 14.5 (36.83)
18 (45.72) 22.5 (57.15)
9.5 (24.13) 9.5 (24.13)
10" 12"
0.5 to 1.0 0.75 to 1.25
(14.16 to 28.32) (21.24 to 35.40)