®
GRAND TOURING SERIES
Automotive Subwoofers
GT800, GT800d, GT1000, GT1000d, GT1200, GT1200d, GT1500, GT1500d Owner’s Manual
GENUINE JBL
Specifications
GT Speakers
Specifications:
GT800
GT800d
GT1000
GT1000d
Configuration
8" woofer
8" woofer,
dual voice coil
10" woofer
10" woofer,
dual voice coil
Recommended power amplifier range
Sensitivity (@ 2.83 volt/1 meter)
Frequency response
18W – 200W
93dB
18W – 200W
93dB
18W – 260W
94dB
18W – 260W
94dB
35Hz – 5kHz
35Hz – 5kHz
30Hz – 3.5kHz
30Hz – 3.5kHz
Mounting Depth
Top mount
Bottom mount
3-13/16" (97mm)
4-5/16" (110mm)
3-13/16" (97mm)
4-5/16" (110mm)
5-1/8" (131mm)
5-5/8" (143mm)
5-1/8" (131mm)
5-5/8" (143mm)
Dimensions
Cut-out diameter
7-1/8" (181mm)
7-1/8" (181mm)
9-1/4" (235mm)
9-1/4" (235mm)
Specifications:
GT1200
GT1200d
GT1500
GT1500d
Configuration
12" woofer
12" woofer,
dual voice coil
15" woofer
15" woofer,
dual voice coil
Recommended power amplifier range
Sensitivity (@ 2.83 volt/1 meter)
Frequency response
18W – 280W
95dB
18W – 280W
95dB
18W – 300W
97dB
18W – 300W
97dB
25Hz – 3kHz
25Hz – 3kHz
20Hz – 2kHz
20Hz – 2kHz
Mounting Depth
Top mount 3-3/8" (86mm)
Bottom mount
5-3/4" (147mm)
6-1/4" (159mm)
5-3/4" (147mm)
6-1/4" (159mm)
6-11/16" (170mm)
7-3/16" (183mm)
6-11/16" (170mm)
7-3/16" (183mm)
Dimensions
Cut-out diameter
11-1/8" (283mm)
11-1/8" (283mm)
13-15/16" (355mm)
13-15/16" (355mm)
01
Sealed enclosures exert the most
control over the motion of a sub-
woofer because the air acts like
a spring against the motion of
the woofer cone. Larger boxes
allow for more excursion (cone
movement), thus more low-
adequate woofer control when dri-
ven below the port tuning range,
so proper design is important. A
fourth-order bandpass box will
have the lowest overall cone
excursion at the expense of limited
bandwidth.
2. Seal all joints with glue and
screws; do not use nails. We
recommend “deck” or “zip” screws
since they have coarse threads
for better grip and don’t require
pre-drilling holes. Once the box
has been tested, seal all interior
joints with silicone caulk.
(i.e., entire box is stuffed with
frequency output for the amount
of power used. When placed in a
sealed box larger than the com-
pliance (Vas) of the subwoofer, it
will perform as if it were in an
infinite baffle installation.
loosely-packed polyester fiberfill).
In addition, there are a number of
points you’ll want to keep in mind
as you construct an enclosure:
4. Use PVC or ABS pipe for ports.
Keep in mind that the openings at
either end of the port must be at
least one port diameter away
from any obstructions, including
filling material inside or outside
the box. Rectangular vents can
be used as long as the cross-
section area matches the
3. Depending on the application,
fill the enclosure according to the
design you have chosen from the
enclosed data sheet in one of three
ways: zero-percent fill (i.e., no
fill), or 50-percent fill (i.e., 1"-
thick polyfill sheets on all inside
walls except where subwoofer is
mounted), or 100-percent fill
1. Use 3/4" (19mm) MDF (medium-
density fiberboard) or marine
birch plywood to build an enclosure.
Enclosures for 12" and larger
subwoofers, or small subwoofers
driven by high-power amplifiers,
should be constructed using 1"
(25mm) material.
Vented and bandpass enclosures
have the lowest amount of excur-
sion for the amount of sound out-
put. This is a result of port tuning
reinforcing the sound output.
recommended port-area values
in the enclosed data sheet.
Vented boxes will not provide
01
Power-Handling
Limitations
The power-handling capability of
any woofer is related to both its
ability to dissipate heat and the
maximum excursion limits of its
cone. Once the speaker’s voice
coil moves outside the magnetic
gap, power can no longer be con-
verted into motion, and all the
amplifier’s power is converted
into heat in the voice coil. This
voice-coil heating is the largest
detriment to speaker longevity,
so overexcursion (driving the
speaker past Xmax) should be
avoided. Since speaker-cone
excursion is different for each
type of enclosure, power handling
is different for each enclosure.
• Voice-coil overheating and burn-
ing due to over-excursion is often
caused by overdriving an ampli-
fier into “clipping.” A severely
clipped signal, or squarewave,
contains nearly twice the power
of a clean sine wave at the same
level. Bass that sounds broken up
and distorted at higher volumes
usually indicates that the ampli-
fier is being asked to deliver
subwoofer will likely be half its
rated power in this application.
• Study the excursion curves on
the enclosed GT Series data
sheet and note the differences
for different enclosure applica-
tions. The type and size of box
used will produce different excur-
sion demands on the enclosed
subwoofer and, consequently,
different levels of power han-
dling. As long as recommended
parameters are used, the sub-
woofer will perform properly in
its enclosed environment.
However, any design deviation
may result in less than optimum
performance, and may also
subject the subwoofer to over-
excursion that can eventually
damage the speaker. For
additional help with this issue,
please contact your authorized
JBL dealer.
power beyond its ability.
• Infinite baffle or “free air”
mounting applications allow for
greater cone excursion than sub-
woofers mounted in an enclosure.
In order to compensate, recognize
that the power-rating value of the
Declaration of Conformity
We, JBL Europe A/S
Kongevejen 194B
DK-3460 Birkerød
DENMARK
declare in own responsibility, that the products described
in this owner’s manual are in compliance with technical
standards:
EN 50 081-1/1992
EN 50 082-1/3.1995
Steen Michaelsen
JBL Europe A/S
Birkerød. DENMARK. 2/98
JBL Consumer Products
250 Crossways Park Drive
Woodbury, NY 11797
8500 Balboa Blvd.
Northridge, CA 91329
800-336-4JBL (4525)
Part No. GTAUTOSUBOM
Made in USA
|