JBL Grand touring series User manual

Introduction ...................................... 3
Features .................................... 4
About Installation ............................. 4
Quick Start ...................................... 5
System Design Using the GTSlSOx ..................... 6
Speaker Requirements .......................... 6
Signal Sources ................................ 7
Other Components ............................. 7
Typical Applications ........................... 8
Warnings and Tips ................................ 10
Installation Precautions. ........................ 10
Mounting Locations ............................ 11
Installation and Use ............................... 12
Controls and Connectors ........................ 12
Internal Adjustments ........................... 14
Speaker-Level Input Impedance Adiustments ..... 14
Crossover Frectuencv Adiustments ............. 14
Mounting Positions ............................ 16
Wiring.. .................................... 17
Power Connections ......................... 17
Ground Wire .............................. 18
Remote In/Out Connection .................... 18
Mute Connection ........................... 19
Speaker Connections ........................ 19
Audio Input Connections ..................... 22
Line-Level Input Connections .............. 22
Speaker-Level Input Connections ........... 22
Simultaneous Speaker Level and Line Level ... 23
Using Rem-Out Capabilitv
Input Mode Switch . . . . .
Input Gain Adiustment . . . . . . .
Adiusting the Gain . . . . . . .
Other Important Characteristics . . .
Maintenance . . . . . . . . . . . . . . .
Add-On and Upgrade Steps . . .
In Case of Difficulty . . . . . . . .
Solving Noise Problems . . . .
Svstem Noise . . . . . . . . . .
Vehicle Noise . . . . . . . . . . .
Specifications . . . . . . . .
Warranty . . . . . . . . . . .
Serial Number
Dealer Name
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City, State, Zip
Sales Receipt Number
Date of Purchase

Introduction
Thanks for purchasing your new
GT series automotive amplifier.
The GT series amplifier you have
chosen includes many unique
features to enhance its perfor-
mance and utility. The power
amplifier circuitry is a fully
discrete design notable for its
low distortion and unusually
clean and clear sound qualitv.
Your GT series amplifier will
easily connect to virtually any
car audio svstem, whether it is
factory installed or purchased
separately.
In addition to conventional pre-
amp-level inputs, this model fea-
tures JBL’s Universal Interface
design, which facilitates simple
connection to factory radios with
the low distortion that is usually
only associated with preamp-
level connection. With Universal
Interface, a factory radio can be
used either as the main music
source or combined with a CD
player or changer which includes
volume control capability,
simultaneouslv connected to the
amplifier. BY providing this two-
unit direct connection, Universal
Interface circuitrv eliminates the
need for an FM modulator to
interface a CD player to factory
radios, improving the fidelity of
digital plavback.
In addition, when using a hish-
powered (BTL) radio through
the speaker-level inputs,
Common Sense turn-on circuitrv
senses the common-mode voltage
present on the radio’s speaker
wires, turning the amplifier on
without an additional “remote”
wire.
Also, the built-in active
crossover provides either full-
range, high-pass or low-pass
operation. This lets your GT
series amplifier power either
subwoofer or component speak-
ers in a biamplified system, or
conventional full-range speakers
in simpler systems.
The GTS180x includes preamp-
level outputs which can provide
either full-range, high-pass or
low-pass signal to drive addi-
tional amplifiers. This lets YOU
build systems of virtually any
design without requiring a sepa-
rate electronic crossover.

Features
l Bridgeable Z- or l-Channel
Operation
l Simultaneous Stereo + Mono
Operation
l Built-in lEdB/Octave Freauencv-
Selectable High-Pass and
Low-Pass Crossover
. Preamp Output with Frequency
Selectable High-Pass and
Low-Pass Crossover
l No Current Limiting
l Oversized Floating Rail (OFR)
MOSFET Switch-Mode Power
SUPPIV
l Common Sense 2-Wav Turn-On
. Switchable Bass Boost
. Mute Input - accepts standard
noise gate inputs to silence the
amp during no-music conditions
l Stealth Remote Silent Turn-On
Circuitrv with Power-On
Indicator
l Continuouslv Adiustable Gain
Controls
l Capable of Single-Ended
Operation Into 2-Ohm Loads
l Full Complementarv, Direct-
Coupled, Discrete Power
Amplifier Circuitrv
l Gold-Plated RCA Input
Connectors
l Gold-Plated Power and Speaker
Connectors
l Third Order (18dB per Octave)
Capacitive/Inductive
Power-Supplv Filtering
l Input Mode Switching
l Speaker Output
Short-Circuit Protection
About Installation
Although the GTSlEOx is designed
to make installation as easv as
possible, this is a sophisticated
product that requires proper
installation to realize full perform-
ance potential. Skill with tools, an
understanding of basic electron-
ics, and experience with car
stereo installation is needed to
properlv install this amplifier.
If YOUfeel YOUdo not have the
necessary knowledge and skills
we stronslv recommend that the
installation be performed bv Your
authorized JBL dealer. If the
GTS180x amplifier is installed bv
an authorized JBL dealer, we will
double the length of vour war-
rantv to two years from date of
purchase. Please retain a COPYof
your bill of sale to ensure this
additional coverage.
If you choose to install the GTS
amplifier vourself, read all of the
information in this manual before
you start the installation. Pav
particular attention to the safetv
precautions and notes.
It will save potential problems
later if you take a few minutes to
plan the complete installation
before you start. The routing of
wires, the power SUPPIV connec-
tion points, and the mechanical
installation of the unit should be
completelv thought out before
you begin. Work carefullv and
check each step as it is per-
formed. Before operating the
amplifier, recheck the entire
installation to be sure that each
connection is correct, properly
insulated and secure.

Quick Start
Recommended for
experienced professional
installers only!
Refer to the “Crossover Frequency
Adiustments” and “Speaker-Level
Input Impedance Adiustments”
sections of this manual to see if
YOUwill need to make alterations
to their factory settings. If you are
not using the built-in crossover, or
the speaker-level inputs, you may
skip this step.
1. Disconnect the negative
cable from the battery.
Note: If the vehicle’s radio
features a code-type security
system, make certain YOU
know the code before
disconnecting the battery!
2. Run the recommended mini-
mum (or larger) power cable
(see the swcifications) com-
plete with a fuse (not included)
directly from the oositive
+12V battery terminal to the
desired amplifier location.
Use a 30 amp fuse. Keep the
fuse to within 6” of the battery
terminal, and before the wire
runs through any metal
partition.
Note: All wiring connections
should be made either by solder-
ing with heatshrink tubing insula-
tion or with high-quality crimp-
type insulated connectors installed
with a professional, articulated
crimping tool. Soldering crimp-
type terminals is recommended
for additional security. Never use
wire-nuts, insulation-displacement
connectors (i.e. ScotchLok type),
or “twist and tape” connections.
Do not use elec trical tape; it will
loosen with age and extreme
temperatures.
3. Mount amplifier in the desired
location using four screws.
4. Connect power wiring as
shown in the wiring diagram
on page 17.
5. Connect the outputs from the
head unit to the appropriate
inputs of the amplifier
according to the wiring dia-
gram (page 17) with either
high quality low-level signal
cables (twisted pair is.best)
with RCA plugs, with the
supplied speaker-level input
connector, or both.
6. Connect the speakers to
the amplifier according to
the wiring diagrams on
Pages 8 and 9.
7. Turn the input gain adiust-
ment to the l/4 position.
8. Set the crossover switches as
desired.
05
9. Set the input mode switch to
stereo, left + right or risht-
input-only operation.
10. Set the bass boost switch to
the desired position.
11. Reconnect the negative bat-
tery cable.
12. Turn on the signal source at a
low volume level and check
for the correct output from
each speaker.
13. Adiust the amplifier gain con-
trol using the Procedure
described in the “Adiustins
the Gain” section (page 25).
14. Read the rest of the manual to
get maximum use ond enioy-
ment from your amplifier.

System Design Using the GTSl80x
Speaker Requirements
When used in the non-bridged
mode the GTS180x can easily
drive 2-ohm speaker loads. When
only one speaker is connected to
each channel, virtuallv anv
conventional speaker can be
used. When two speakers are
connected in parallel to a given
channel, each speaker must have
a minimum impedance of at
least 4 ohms. This ensures that
the combined load will not drop
below 2 ohms. Although the
amplifier will not be damaged,
load impedances lower than
2 ohms will eventually cause the
amplifier to overheat, activating
the Protection circuits and
causing the unit to shut off until
it cools down sufficientlv.
Parallel Wiring
(+I
8 Ohms
Nomtnal
Impedance
When the GTS180x is in bridged The GTSlEOx must not be used
mode, the combined impedance with speakers that have either
of the speaker (or speakers) con- one of their input terminals wired
netted to the bridged channel to the frame of the speaker or to
should be at least 4 ohms. the chassis of the vehicle.
Sustained operation of the
GTSl8Ox in bridged mode with
less than 4 ohms will likely cause
overheating. If monaural ooera-
tion is desired, and two 4 ohm
speakers are used, it is best to
connect each speaker to an indi-
vidual amplifier channel and use
the “L+R” mode on the input-
mode switch to provide monaural
operation.

Signal Sources
The low-level preamp outputs of
any radio/tape deck, CD player
or nreamol equalizer so equipped
can drive the GTS180x. The gain
control of the GTSlBOx is used to
match the amplifier’s input sensi-
tivity to the outout voltage of the
source. This matching is impor-
tant to keep the noise level low
and is explained in the “Adiusting
the Gain“ section of this manual
(see page 25).
Thanks to Universal Interface
circuitry, the GTS180x can also
be connected to power amplifiers,
radios or equalizers that are
equipped with only speaker
outputs bv connecting them
through the speaker level input
connector. Inside the GTSlEOx,
the speaker-level and preamp-
level inputs are connected
through a mixing circuit, which
allows them to be used
simultaneously. Therefore a low-
level source, such as a CD player
equipped with a volume control,
may be connected to the preamp-
level inputs at the same time as a
powered radio/tape unit is
connected to the sneaker-level
inputs. This provides a higher
performance alternative to an
FM modulator connection when
YOUwish to add CD capability to
a factory cassette stereo.
Switching from one source to the
other is as simple as turning the
desired source on and turning the
undesired one off - no additional
switches or relay connections are
needed.
Other Components
The system options of the
GTSlEOx are numerous. All JBL
amplifiers are designed with
sufficient adiustment range to
match with the accepted “nor-
mal” voltages and impedances
used by virtually all car audio
components. With very few
exceptions, the GTSlEOx will
match up with nearly anv
equipment you already have.

T’ypicclI ~~~~~~~t~~~s
The following diagrams show the
most common basic svstem
configurations of the GTS180x.
One or more of these “building
blocks” may be combined to
form elaborate system designs.
For additional ideas, refer to the
“Add-On and Upgrade Steps”
section (see page 27).
Application 1
Stereo Full-Range or Subwoofer Operation
Application 2
Bridge-Mode Operation
Sing/eAmplifier:
Subwoofer Operation (Mono)
DualAmplifier:
Subwoofer Operation (Stereo)

Application 3
Bi-amplified, Three-Channel
SubwooferEatellite Svstem.
Application 4
Bi-amplified System Using
Preamp Output Capability.

Warnings and Tips
Fnstallation Precaufims
10
Before beginning the installation
of the amplifier read the follow-
ing points carefully. Failure to
heed these warnings could result
in personal iniury or damage to
property.
l The GTS180x should be installed
only in vehicles that have 12-
volt negative ground electrical
systems. Connection to other
types of electrical systems may
damage the amplifier and/or the
vehicle’s electrical system.
l Before beginning the instollo-
tion, disconnect the negative
(ground) cable from the vehi-
cle’s battery. This will prevent
accidental short circuits while
working on the installation.
Reconnect the cable only after
the installation is complete and
the wiring has been carefully
checked to be sure there are no
exposed wires or short circuits
and everything is properly and
securely connected. Note: If the
vehicle’s radio features a code-
type security system, make cer-
tain YOUknow the code before
disconnecting the battery!
l Work in an area that is well
ventilated.
l Wear eve protection whenever
cutting, drilling or filing any
parts of the vehicle.
l Wear ear protection when using
high-speed drills, saws, sanders,
or grinders. We want YOUto be
able to eniov the system once it
is installed.
l Before cutting or drilling any
holes in the vehicle, inspect the
area carefully to be sure there
are no electrical wires,
hydraulic brake lines, fuel lines,
or fuel tanks that may be dam-
aged while doing so. Such com-
ponents may be hidden within
double-walled panels or struc-
tural members of the vehicle, so
be extremely cautious.
l Do not bypass or modify the
fuse on the chassis of the ampli-
fier. Do not replace the fuse
with one rated for higher cur-
rent levels. Doing so could
result in damage to the ampli-
fier and the vehicle’s electrical
system. Repeated blowing of the
power supply fuse indicates a
problem within the amplifiers or
improper installation.
l An additional power SUPPIY fuse
(not included) must be located
as close as possible to the bat-
tery on the +12V wire to mini-
mize the chance of electrical
system damage or fire in the
event of a short circuit in the
power SUPPIY wire. This precau-
tion is extremely important; do
not ignore it! If the heavy-gauge
power wire required with the
GTS180x ever becomes shorted
to ground, the wire will get
extremely hot, causing the insu-
lation to burn off, and this will
likely cause a fire if the
circuit is not properly fused.