JBL GRAND TOURING GTS 180 Amplifier (stereo) Owner's Manual

JL Consumer Pedic he. NT :
Bad > /1-CHANNEL AUTOMOTIVE POWER AMPLIFIER
ee OWNERS MANUAL
H A Harman International Company
Part Мо. JBLGTS1800M
Table of Contents
1. ПНОЧисСНОп ........ ини 3
1.1 Features ........... ини нии 4
1.2 About Installation... ss 4
D. QUICK аи .......... или нии 5
3. System Design Using the GTS180 ............ нии 6
3.1 Speaker Requirements... 6
3.2 Signal Sources ........eeneeneenennennnnnnnnenssnnneser teten 6
3.3 Other Component .................. еее eceeceeeeaeeeess 7
3.4 Typical Applications... 7
4. Warnings and Tips... ss 9
4.1 Installation Precautions ss 9
4.2 Mounting Locations ss 9
5. Installation and Use sise 10
5.1 Controls and Connectors................... ss 10
5.2 Internal Adjustments......................................... ss 11
Speaker-Level Input Impedance Adjustments...................…… 11
Crossover Frequency Adjustment ....................................... 12
5.3 Mounting Positions ................ een ve deeeeeecaneeeeeeees su 18
5.4 МИА... инете, 14
Power Supply Connections ............. линии инининии nn 15
Speaker Connections... 16
Audio Input Connections ss 19
Line-Level Input Connections... ss. 19
Speaker-Level Input Connections .….................................... 19
Simultaneous Speaker-Level + Line-Level........ ee 19
5.5 Input Mode Switch... 20
6. Input Gain Adjustment ss 21
7. Other Important Characteristics .…................................................………… 22
8. Maintenance .............. ини ини 22
9. Add-On and Upgrade Steps.....…............................... ss. 23
10. м Case Of Difficulty ss 25
11. Solving Noise Problems... 27
11.1 System Noise ss 27
11.2 Vehicle Noise... ss mel
12. Specifications... 30
Owner’s Warranty Information
Model Number |
Serial Number
Dealer Name
City, State, Zip
Sales Receipt Number
Date of Purchase
2
1. Introduction
Thanks for purchasing your new GT
series automotive amplifier. The GT
series amplifier you have chosen
includes many unique features to
enhance its performance and utility. The
power amplifier circuitry is a fully dis-
crete design notable for its low distortion
and unusually clean and clear sound
quality. Your GT series amplifier will
easily connect to virtually any car audio
system, whether it is factory installed or
one purchased separately.
In addition to conventional preamp-
level inputs, this model features JBL's
Universal Interface design, which facili-
tates simple connection to factory radios
with the low distortion that is usually
only associated with preamp level con-
nection. With Universal Interface, a fac-
tory radio can be used either as the
main music source or combined with a
CD player or changer, which includes
volume control capability, simultane-
ously connected to the amplifier. By
providing this two-unit direct connection,
Universal Interface circuitry eliminates
the need for an FM modulator to inter-
face a CD player to factory radios,
improving the fidelity of digital playback.
In addition, when using a high-powered
(BTL) radio through the speaker-level
inputs, Common Sense turn-on circuitry
senses the common-mode voltage
present on the radio’s speaker wires,
turning the amplifier on without an addi-
tional “remote” wire.
Also, the built-in active crossover pro-
vides either full-range, high-pass or low-
pass operation. This lets your GT series
amplifier power either subwoofer or
component speakers in a bi-amplified
system, or conventional full-range
speakers in simpler systems.
The GTS180 also includes preamp-level
outputs which can provide either full-
range, high-pass or low-pass signal to
drive additional amplifiers. This lets you
build systems of virtually any design
without requiring a separate electronic
crossover.
1.1 Features
e Made in USA
¢ Bridgeable 2 or 1 Channel Operation
+ Simultaneous Stereo + Mono Operation
¢ Built-in 18dB/Octave Frequency
Selectable High-Pass and
Low-Pass Crossover
e Preamp Output with Frequency
Selectable High-Pass and
Low-Pass Crossover
+ No Current Limiting
e Oversized Floating Rail (OFR)
MOSFET Switch-Mode Power Supply
e Common Sense 2-Way Turn-On
e Switchable Bass Boost
» Mute Input — accepts standard noise
gate inputs to silence the amp during
no music conditions
e Stealth Remote Silent Turn-On
Circuitry with Power-On Indicator
e Continuously Adjustable Gain Controls
+ Capable of Single-Ended Operation
Into 2-Ohm Loads
e Full Complementary, Direct-Coupled,
Discrete Power Amplifier Circuitry
e Gold-Plated RCA Input Connectors
e Gold-Plated Power and Speaker
Connectors
e Third Order, (18dB per Octave)
Capacitive/Inductive
Power-Supply Filtering
* Input Mode Switching
e Speaker Output Short Circuit
Protection Circuitry
1.2 About Installation
Although the GTS180 is designed to
make installation as easy as possible, it
is a sophisticated product that requires
proper installation to realize its full per-
formance potential. Skill with tools, an
understanding of basic electronics, and
experience with car stereo installation
are needed to properly install this ampli-
fier. If you feel you do not have the nec-
essary knowledge and skills we strong-
ly recommend that the installation be
done by your authorized JBL dealer.
If the GTS180 is installed by an autho-
rized JBL dealer, we will double the
length of your warranty to two years
from date of purchase. Please retain a
copy of your bill of sale to insure this —
additional coverage.
If you choose to install the GTS180
yourself, read all of the information in
this manual before you start the installa-
tion. Pay particular attention to the safe-
ty precautions and notes.
It will save potential problems later if
you take a few minutes to plan the com-
plete installation before you start. The
routing of wires, the power supply con-
nection points, and the mechanical
installation of the unit should be com-
pletely thought out before you begin.
Work carefully and check each step as
it is performed. Before operating the
amplifier, recheck the entire installation
to be sure that each connection is cor-
rect, properly insulated and secure.
UBL
2. Quick Start
Recommended for experienced
professional installers only!
Refer to the “Crossover Frequency
Adjustments” and “Speaker Level Input
Impedance Adjustments” sections of
this manual! to see if you will need to
make alterations to their factory set-
tings. 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: № the vehicle's
radio features a code type security
system, make certain you know
the code before disconnecting the
battery!
2. Run a minimum AWG #10 (maxi-
mum: AWG #8) power cable com-
plete with a 30 amp fuse (not includ-
ed) for the GTS180 directly from the
positive +12V battery terminal to
the desired amplifier location. 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 soldering with heatshrink
tubing insulation 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-displace-
ment connectors (i.e. ScotchLok type),
or “twist and tape” connections. Do not
use electrical tape; it will loosen with age
and extreme temperatures.
13.
14.
. Mount amplifier in the desired loca-
tion using four screws.
. Connect power wiring as shown in
the Wiring Diagram on page 14.
. Connect the outputs from the head
unit to the appropriate inputs of the
amplifier according to the Wiring
Diagram (page 14) with either high
quality low-level signal cables (twist-
ed pair is best) with RCA plugs, with
the supplied speaker-level input
connector, or both.
. Connect the speakers to the ampli-
fier according to the wiring diagrams
in section 3.4.
. Turn the input gain adjustment to
the % position.
. Set the crossover switches as
desired.
. Set the input mode switch to stereo,
left + right or right input only operation.
. Set the bass boost switch to the
desired position.
. Reconnect the negative battery cable.
‚ Turn on the signal source at a low
volume level and check for the cor-
rect output from each speaker.
Adjust the amplifier gain control
using the procedure described in
the “Adjusting the Gain” section
(page 21).
Read the rest of the manual to get
maximum use and enjoyment from
your amplifier.
3. System Design
Using the GTS180
3.1 Speaker Requirements
When used in the non-bridged mode the
GTS180 can easily drive 2 ohm speaker
loads. When only one speaker is
connected to each channel, virtually any
conventional soeaker may 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 sufficiently.
Parallel Wiring
2 Ohms
Nominal
Impedance
(-)
Series Wiring
8 Ohms
Nominal
Impedance
(-)
When the GTS180 is in bridged mode,
the combined impedance of the speaker
(or speakers) connected to the bridged
channel should be at least 4 ohms.
Sustained operation of the GTS180 in
bridged mode with less than 4 ohms will
likely cause overheating. If monaural
operation is desired, and two 4-ohm
speakers are used, it is best to connect
each speaker to an individual amplifier
channel and use the “L+R” mode on the
input-mode switch to provide monaural
operation.
The GTS180 must not be used with
speakers that have either one of their
input terminals wired to the frame of
the speaker or to the chassis of the
vehicle.
3.2 Signal Sources
The low level preamp outputs of any
radio/tape deck, CD player or preamp/
equalizer so equipped can drive the
GTS180. The gain control of the
GTS180 is used to match the amplifier's
input sensitivity to the output voltage of
the source. This matching is important
to keep noise low and is explained in
the “Adjusting the Gain” section of this
manual (see page 21).
Thanks to Universal Interface Circuitry,
the GTS180 can also be connected to
power amplifiers, radios or equalizers
that are equipped with only speaker
outputs by connecting them through the
speaker level input connector. Inside
the GTS180, 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 speaker-level inputs. This
provides a higher performance
alternative to an FM modulator
connection when you wish 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.
3.3 Other Components
The system options of the GTS180 are
numerous. All JBL amplifiers are
Application 1
Stereo Full-Range or Subwoofer Operation
Full-Range Operation
Speaker Output
Crossover
Switch
Input Mode
Switch
Flat Stereo
Subwoofer Operation
Speaker Output
Crossover
Switch
Input Mode
Switch
Low Pass Stereo
Main speakers are driven by head unit or
additional amplifier.
designed with sufficient adjustment
range to match with the accepted “nor-
mal” voltages and impedances used by
virtually all car audio components. With
very few exceptions, the GTS180 will
match up with nearly any equipment
you already have.
3.4 Typical Applications
The following diagrams show the most
common basic system configurations of
the GTS180. A combination of 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” section (see
page 23).
SS
L
Preamp or
L | Speaker-Level | В}
Input
GTS180 F BT
L-ÉL+ R-I R+
2 or 4-Ohm
cee CE, FullRange
+ Speakers or
Subwoofers
Application 2
Bridge-Mode Operation
Single Amplifier:
Subwoofer-Operation (Mono)
Speaker Output |
Amp Crossover ‚Input Mode | For Dual-Amplifier | | For Singie Amplifier |
Switch Switch y 1 Full-Range or Subwoofer Use | | Subwoofer Use |
Lumens LL — mme }
8 Low Pass L+R E L
Main speakers are driven by head unit or |
additional amplifier.
pee ee ee moon | |
| Dual Amplifier: 5 |
| Subwoofer-Operation (Stereo)
| Speaker Output |
Amp Crossover Input Mode
Switch Switch GTS180 ‚ GTS180
| A+B| Low Pass R A alli | B| E
, = |
ı Full-Range Operation (Stereo)
| Speaker Output 4-Ohm L- A+ | 4-Ohm L-|¡R+
| Amp Crossover input Mode Full-Range ı Fui-Range
| Switch Switch Speaker or - + i Speakeror — +
| Subwoofer | Subwoofer
| A+B Flat R
Application 3 ==
. el оо
Bi-amplified, Three-channel Front Rear
Subwoofer/Satellite System. Г \
Speaker Output L В Preamp ог L
Amp Crossover Input Mode Speaker-Level
Switch Switch Input
A High Pass Stereo
B Low Pass L+R
GTS180 GTS180
Stereo Subwoofers may be used by configuring AF В? ‘A
Amp B as shown in Application #1.
p in Application #1 L-ER+ Ry LR.
2 or 4-Ohm 4-Ohm
Fuli-Range Subwoofer
Speakers
E PU
FX
reamp
Intput
Application 4 O =
. ope ‘ - LL
Bi-amplified System Using Preamp or »
Preamp Output Capability. Speaker-Level If
Input an p
Speaker Output L put ЦЕ Е А
Атр Crossover Input Mode Preamp À
Switch Switch Output |
Crossover
A High Pass Stereo Flat
B Low Pass L+A Doesn't Matter
GTS180|| GTS180
Stereo Subwoofers may be used by configuring A B i
Amp B as shown in Application #1 or by
using dual GTS amplifiers as shown in Е- |+ В-| R+ L-
Application #2. 9 or 4-Ohm 4-Ohm
Full-Range Subwoofer
ey, Rt
- Ent + - +
4. Warnings and Tips
4.1 Installation Precautions
Before beginning the installation of the
amplifier read the following points care-
fully. Failure to heed these warnings
could result in personal injury or damage
to properiy.
e The GTS180 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 vehi-
cle’s electrical system. |
¢ Before beginning the installation, dis-
connect the negative (ground) cable
from the vehicle’s battery. This will pre-
vent accidental short circuits while
working on the installation. Reconnect
the cable only after the installation is
complete and the wiring has been care-
fully checked to be sure there are no
exposed wires or short circuits and
everything is properly and securely con-
nected. Note: If the vehicle’s radio fea-
tures a code type security system,
make certain you know the code before
disconnecting the battery!
» Work in an area that is well ventilated.
¢ Wear eye protection whenever cutting,
drilling or filing any parts of the vehicle.
e Wear ear protection when using high
speed drills, saws, sanders, or grinders.
We want you to be able to enjoy the
system once it is installed.
e 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 damaged while doing
so. Such components may be hidden
within double-walled panels or structur-
al members of the vehicle, so be
extremely cautious.
e Do not bypass or modify the fuse on the
chassis of the amplifier. Do not replace
the fuse with one rated for higher cur-
rent levels. Doing so could result in
damage to the amplifier and the vehi-
cle’s electrical system. Repeated blow-
ing of the power supply fuse indicates a
problem within the amplifiers or improp-
er installation.
e An additional power supply fuse (not
included) must be located as close as
possible to the battery on the +12V wire
to minimize the chance of elecirical sys-
tem damage or fire in the event of a
short circuit in the power supply wire.
This precaution is extremely important;
do not ignore it! If the heavy gauge
power wire required with the GTS180
ever becomes shorted to ground, the
wire will get extremely hot, causing the
insulation to burn off and will likely
cause a fire if not properly fused.
4.2 Mounting Locations
There are several factors to consider
when selecting a mounting location for
the GTS180.
e lt must be solidly mounted in a place
where it will not be subjected to exces-
sive shock and vibration.
* Under no circumstances should the
amplifier be mounted where it will be
exposed to moisture or extreme heat.
* Try to mount the amplifier where
the main +12 volt power supply
terminal, which must be connected
directly to the battery, can be kept
relatively short.
* The GTS180 must be mounted in a
place where air can circulate around
the fins on the chassis. Good air circu-
lation around the amplifier will make it
operate at lower temperatures and
reduce the chance of the thermal pro-
tection circuits being triggered. The
installation positions that provide the
most efficient air circulation around the
amplifier are shown below.
BEST-Vertical Mounting
|
AIR FLO
GOOD-Horizontal Mounting
AIR FLOW
|
|
1
NEVER-Mount Upside Down
e Use a mounting location that allows
access to the wiring connections and
level adjustments. This allows the unit
to be mounted before these connec-
tions and adjustments are made. If the
amplifier must be mounted in an inac-
cessible location, it may be easier to
mount it after the wiring connections
and level adjustments are complete.
5. Installation and Use
5.1 Controls and Connectors
_. ® Mute Input
| © Battery Ground
| © Battery (+12v) In Co tor
al — & Remote In/Out
$s Ce) +— © Fuse
- @ Speaker Outputs
SPEAKER
QUIPUT
10)
[900 |
00
(O
— à High Level Speaker Inputs
Sera LEVEL
ru
в (Je)
wel‘
1779 Preamp Level RCA Outputs
LIKE ТЕМУР
PUT АЛ
L L
010
o
—— © Preamp Level RCA Inputs
— ® Gain Control
Е
а
Es г a
SE ——9 Preamp Crossover
#5 = Frequency selector
2
ES Е 3
eo mE ———— ® Amplifier Crossover
Ron Frequency Selector
=
= о Input Mode Selector
@ Bass Boost
JBL
10
1. Preamp-Level Input Connector — Use
these connectors for line (preamp) level
input to the amplifier. -
2. Preamp-Level Output Connector —
Use these outputs to send line level
signal to additional amplifiers.
3. Speaker-Level Input Connector — Use
this connector for speaker level input
signals. A wire harness is supplied for
use with this connector. See “Speaker
Level Input Connections” section (page
19) for wiring instructions. This input
also includes JBL's Common Sense
input circuitry which turns the amplifier
on as soon as the high powered head
unit connected to this input is turned on.
4. Speaker Output Connector — Connect
speaker wiring to this connector. See
“Wiring” directions for more information.
5., 6., 7., 8. Power Connector —
Connection for power, remote, and
muting wires. See “Power Connections”
for information on proper connections
(page 15).
9, Fuse - 30 Amp ATC type.
10. Gain Control — Use this control to
adjust the input sensitivity of the ampli-
fier. See the “Adjusting the Gain”
section for tips on proper setup.
11. Preamp-Output Crossover Switch —
This switch controls the built-in crossover
that is directed to the preamp-output con-
nectors. Set the switch to “Flat” for full
band operation. Set this switch to “Low-
Pass” to activate the low-pass filter on
the preamp output (for subwoofer use).
Set the switch to “High-Pass” to activate
the high-pass filter for use with satellite
speakers on the preamp outputs.
12. Speaker Output Crossover Switch —
This switch controls the built-in
- crossover that is connected to the
power amplifier circuitry. Set the switch
to “Flat” for full band operation. Set this
switch to “Low Pass” to activate the low
pass filter on the amplifier (for sub-
woofer use). Set the switch to “High
Pass” to activate the high pass filter for
use with satellite speakers.
13. Input Mode Selector — This switch is
used to set the input mode for both
preamp and speaker-level inputs.
Set this switch to Stereo for normal
operation using both left and right
inputs. Set this switch to "НВ" to drive
both the left and right output channels
with only a single input on the right
channel. Set this switch to “L+R” to sum
the left and right inputs for a mono
output on both amplifier channels. The
input mode selection switch does not
effect the preamp outputs.
14. Bass Boost Switch — This activates
a built-in Bass Boost circuit used to
increase low-bass output.
Power Indicator LED (on chassis top) —
LED steadily illuminates for normal
operation. LED blinks when protection
circuitry or muting is engaged and dur-
ing initial power-up.
5.2 Internal Adjustments
Speaker-Level Input
Impedance Adjustments
The speaker level inputs of the GTS180
come factory set with 100K ohm input
impedance. This will provide the lowest
distortion operation from the speaker out-
puts of most modern head units by
11
reducing the power the amplifier in the
head unit must deliver to practically noth-
ing. The resulting signal will practically be
as free from noise and distortion as a
preamp-level connection. On some older,
or lower-priced head units, this load will
not facilitate proper fader operation. To
allow for this, we have provided the abili-
ty to change the input impedance of the
speaker-level inputs to 15 ohms. This is
accomplished by setting the jumpers
shown in the diagram below.
JUMPER SELECTOR
SELECT 100K OR 15 OHMS
e Е the head unit has 4 channels of built-
in amplification and/or an electronic
fader control, you should leave the
jumpers in the factory set position
(100K ohm).
e If the head unit has 2 channels of
amplification, with a speaker-level
fader, the jumpers should be set to the
15-ohm position. This will always be a
rotary-type control, not one controlled
by electronic pushbuttons.
If you are not certain of the type of fader
contro! your unit has, measure the resis-
tance across one set of speaker outputs
with an ohmmeter (with the head-unit
off). Adjust the fader control through its
entire adjustment range. If there is a
change in the resistance as the control
is adjusted, set the jumpers to the
15-ohm position.
Crossover Frequency Adjustments
The GTS180 amplifier includes built-in
frequency selectable crossovers. One
crossover is connected in series with the
amplifier circuitry and the other crossover
is connected to the preamp level output
jacks. These crossovers can be set in
either the “flat” (full bandwidth operation),
Low Pass (subwoofer operation), or High
Pass (satellite operation). More details on
the use of these crossovers are given in
the “Add-On and Upgrade Steps” section.
e The crossover frequencies are set by
“chips” inside the amplifier. These “chips”
are simply a set of resistors, connected
across the pins and molded into a single
package. The crossover frequencies
may be changed to any value desired by
changing the resistor network. JBL has
“chips” available in the popular values
listed in the table below. If none of these
suit your system, you may purchase
compatible resistor networks from a local
electronics store, or you may build your
own custom values from discrete resis-
tors mounted on a 14-pin “DIP Header”
using the instructions which follow.
Frequency Resistor JBL Part
Value Number
50Hz 47k О 1-23-750 _
80Hz 33k Q 1-23-817 _
120Hz 22k 0 1-23-820 _
200Hz 12kQ 1-23-821 _
250Hz 10k © 1-23-810 __
375Hz 6.8kQ 1-23-822 _
500Hz ATKQ 1-23-815
650Hz 3.9k Q 1-23-823
2.5kHz 1k Q 1-23-824
5kHz 470 Q 1-23-816
Regardless of whether you build or buy
it, the necessary resistor network has
the following configuration:
Custom “Chip” Construction
TT Eu
| eae Sela fe ee ee Ae AD
:
4]
4
or, ve a и ,
e Each resistor in the package has the
same value.
elf you know the crossover frequency
you want, you can calculate the resis-
tor value necessary by solving the fol-
lowing equation:
Resistor 2,500,000
Value = Crossover
in Ohms Frequency in Hz
« Use the following equation if you have
a resistor pack of a known value, and
want to find its crossover frequency:
Crossover 2,500,000
Frequency = Crossover
in Hz Resistor Value in Ohms
e To build “chips” from discrete resistors,
solder the resistors to a standard 14-pin
“DIP Header’ according to the diagram.
lf a DIP Header is not available, you may
bend the leads of 4"-watt resistors 90
degrees, trim them to %"-length, and
insert them direcily into the chip sockets.
To change the crossover frequency
change the resistor network as follows:
1. Remove the screws from the bottom
panel as shown next.
2. Select which resistor module, high
pass or low pass, that you wish to
change.
3. A chip puller, which can be obtained
from any electronics store, is used
to remove the resistor chip. Pull the
resistor chip from ihe socket as
shown in the figure below.
4, Place the new module in the socket
making sure all pins are lined up
with the socket holes. Press the
module firmly into the socket.
5. Replace the bottom lid.
For further information on how to use
the speaker output and preamp output
crossovers for system building see the
“Typical Applications” and “Add-On
and Upgrade” sections.
5.3 Mounting Positions
Place the amplifier in the installation
location. Use a pen or pencil to mark
the four mounting screw hole locations.
Set the amplifier aside and drill the
12
13
holes for the mounting screws. (Note: If
the surface you are mounting the amp
to is covered with carpeting or uphol-
stery, cut a small “x” in the material at
each screw hole location before drilling
the holes. This will help prevent tearing
or stretching of the material and carpet
fibers from being pulled out.) Set the
amplifier in position and align the holes
on its side with the holes previously
drilled. Put washers on the four sheet
metal screws provided and drive them
into the mounting panel. Tighten the
screws evenly until the unit is solidly
mounted.
Cassette/CD Tuner
о ЕЕ) С)
E 0 EDO
|
T
Antenna input
Cassette/Receiver
Power Supply
Wires
oo
om
5.4 Wiring
Proper wiring of the GTS180 and the
associated components is extremely
important for proper performance and
long term reliability. Using the proper
type of wire is very important. If a spe-
cific type of wire is required for a certain
application, it will be noted.
Route the wiring through the car care-
fully. Do not allow wires to lay against
sharp sheet metal edges or any other
surfaces that might wear away or cut
Cassette/CD Tuner
Speaker Level Output Connection
(Use only when line level ouput
is not avaitable)
CD Player
or Changer
=
Power Cassette/CD Preamp Output Amplifier
Antenna Power
Relay 2 ma Connection
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IN + |
- - Speakers >
Blue w/White Stripe - Remote Or/Off
Ignition Switch u
GTS180 - 30 Amp
(Not Included)
| a Main +12V +
— +
Vehicle Battery
Power Ground
Chassis Ground
through the insulation of the wire. Use
insulated strain reliefs, rubber grommets
and plastic tubing to protect the wires
whenever they are run through sheet
metal panels or are placed where they
might be pulled or damaged.
Power Connections
The power input, remote turn-on, and
mute wires are connected to the
GTS180 via the power connector on
the end of the amplifier.
+12V Battery Wire
e Connect a wire directly from the +12
volt terminal of the battery to the
(+) Battery terminal on the amplifier.
For the GTS180, use a minimum of
AWG #10. Use wire that is heat and oil
resistant whenever running wires
through the engine compartment. All
wire-to-wire connections should be sol-
dered and insulated with heat shrink
tubing, or connected through a high
quality insulated crimp-on connector or
secure set-screw type terminal blocks.
Never leave bare wire exposed.
Terminate wires with crimp or solder-
on lug terminals whenever appropriate.
« The GTS180 will draw as much as 30
amps from the vehicle’s electrical sys-
tem, enough to overload conventional
vehicle wiring. Therefore the +12 volt
power supply must be taken directly from
the positive side of the battery. Do not
connect to the vehicle’s fuse block or
to a wire feeding other accessories.
® To prevent electrical system damage
or fire, a fuseholder and fuse (not
included), maximum 30A, must be
installed in the power supply wire, as
close to the battery as possible, and
before the wire travels through the fire-
wall or other metal panel.
Ground Wire
® Proper grounding is extremely important.
Use a heat and oil-resistant stranded
copper automotive wire equivalent to the
size used for the +12V connection.
Crimp or solder and insulate any wire-to-
wire connections. Keep the ground wire
as short as possible. A ground wire must
be solidiy connected to a major sheet
metal structure of the vehicle such as a
panel near the amp mounting location.
Scrape all paint and primer off the sheet
metal at the grounding point to ensure a
good electrical connection. Attach the
wire to the grounding point with a nut,
bolt and star washer. The high current
demanded by high-powered amplifiers
requires a more secure ground than the
typical sheet-metal screw will provide.
e In some vehicles, such as those that
have non-metal bodies, it may be
necessary to extend the power supply
ground wire and connect it to a frame
rail or even directly to the negative (—)
terminal of the battery.
e When used in elaborate systems with
multiple components, it is common
practice to ground all of the amplifiers
and signal processors to the same
point to prevent noise pickup from a
ground loop. With the extremely high
peak current demands of high pow-
ered amplifiers, this can result in
unstable power delivery to the compo-
nents, due to modulation of the power
ground point by the high power
demands. The advanced, isolated
power supplies used in the GTS180
make common ground installation
15
unnecessary. To prevent ground
loops, they can be grounded close to
their mounting positions. Use of heavy
gauge wire for all grounding, even sig-
nal processors and head units, can
minimize possible noise pickup.
Remote In/Out Connection
« The remote power control system turns
the GTS180 off when not in use to pre-
vent discharging of the vehicle's bat-
tery. Because the JBL GTS180
includes Common Sense 2-way turn
on, when using the speaker level inputs
with a head unit that includes a BTL
power amp it is not necessary to con-
nect the remote wire. The amplifier will
automatically activate whenever you
turn on the head unit. If you are using
the line level inputs, or the speaker
level inputs with a head unit that does
not have a BTL power amp, follow the
remote wire connections listed below.
« Using the REM IN feature — When +12
volts is applied to the remote IN/OUT ter-
minal the amplifier is turned on. A red
LED on the top panel of the amplifier will
illuminate to indicate the amplifier is on. If
the head unit has a +12 volt automatic
antenna or amplifier remote activation
wire, connect it to the “REM IN/OUT”
connector on the GTS180. When the
amplifier is turned on, there is a time
delay of several seconds (longer in cold
weather) before the amplifier will produce
sound. This eliminates the chance of
annoying noises produced by the radio or
signal processors being amplified and
passed to the speakers when the system
is first activated.
+ Some head units have no automatic
antenna or power amp activation wire.
Others have automatic antenna wires
that are “on” only when the radio is used
but not when a tape is played. In such
cases, connect the remote in turn-on ter-
minal to an unused accessory terminal in
the fuse block, or any other +12 volt
source that is turned on and off with the
vehicle’s ignition switch. The remote
on/off system draws negligible current so
a relatively small (18 or 20 gauge) wire
may be used.
e Using the REM OUT feature — The
- "REM IN/OUT" terminal of the GTS180
may be used to turn on other amplifiers
when the GTS180 is being turned on
by the Common Sense Circuitry in the
speaker level input. Simply connect the
head unit speaker level outputs to the
GTS180 speaker level inputs and con-
nect the "REM IN/OUT" terminal to the
remote in terminal of other amplifiers or
signal processors. The GTS180 will
turn on the other amps or processors
whenever the Common Sense circuitry
turns on the GTS180.
Mute Connection
The GTS180 includes a mute input termi-
nal. This amplifier will mute when a 5 to
12V DC signal is applied to the "mute"
input and will be in normal operation
mode with either a ground or nothing
connected to the "mute" input. This
"mute" input is compatible with any after-
market noise gate that puts out a control
voltage of 5 to 12V DC.
Speaker Connections
e When connecting speaker wires, be sure
that no uninsulated wire remains
exposed and no loose strands of wire
touch either an adjoining wire or terminal
or a metal surface. Securely crimp or sol-
16
der all connections and insulate them
with heatshrink tubing.
e Use high quality 16 gauge or larger
(12 gauge maximum) speaker wire for
the amplifier to speaker connections.
Larger wire or special high-perfor-
mance speaker cables may improve
the performance of some systems.
e Be very careful when speaker wire is
routed through a door hinge area to
door-mounted speakers. Use grom-
mets and strain reliefs wherever nec-
essary to prevent damage to the wires.
* The proper speaker connection depends
on whether the GTS180 is used bridged
or stereo. The speakers are connected
to the speaker output connecior.
* To get proper bass response and
stereo imaging, all the speakers in the
system must be “in phase.” The input
terminals of the speakers will be
marked in some way to identify posi-
tive and negative polarity. Make sure
that the positive (+) speaker terminal is
attached to the positive (+) amplifier
connection in every speaker-to-amp
connection. All two-conductor speaker
wire has one conductor marked in
some way so it can be easily traced.
e Stereo Connection — Connect each
speaker to appropriately labeled termi-
nals of the speaker output connector.
¢ Bridged-Mode Connection — Connect the
loudspeaker positive (+) terminal to the
RIGHT channel positive amplifier speak-
er output terminal. Connect the loud-
speaker negative (-) terminal to the
LEFT channel negative amplifier speaker
output terminal. The input-mode switch
should be set to “RIGHT” or “L+R.”
e Simultaneous Stereo + Mono
Connection — The GTS180 may be
used to drive a stereo pair of speakers
with a mono speaker at the same time.
This is sometimes used for center-
channel applications or for inexpensive
subwoofer addition, essentially creating
a 3-channel system. Unlike a true bi-
amplified subwoofer connection how-
ever, this type of system configuration
does not provide fine control of sub-
woofer-satellite balance. It requires the
use of a passive subwoofer crossover
instead of the superior active circuitry
already built-in to the GTS180, and it
does not separate the power amps dri-
ving the satellites from the amps driv-
ing the subwoofer. Therefore this con-
nection is best used for addition of a
center-channel, or as an interim step
as you build up to a true bi-amplified
subwoofer/satellite system. Connect
the main pair of stereo speakers as in
the stereo mode; connect the mono
speaker as described above for
bridge-mode connection. For use in
center channel applications, a high-
power “L-Pad” or power fader can be
used to attenuate the center channel
for proper level matching. For sub-
woofer-satellite use, connect a non-
polarized capacitor in series with each
main speaker, and a high-power induc-
tor (coil) in series with the subwoofer.
Your authorized JBL dealer will help
you choose the correct values for your
particular components. In this configu-
ration, each speaker should have an
impedance which is equal or greater
than 4 Ohms. The input-mode switch
should be set to “STEREO” (See
page 18). |
17
Simultaneous Stereo-Mono
Connection Diagrams
A. Satellite/Subwoofer Subwoofer (Low Pass)
Component Values for
4 Ohm Loudspeakers” (+) | (-)
High Pass Satellite
Cr F :
ossover Frequency: 100Hz Tweeter/Midrange Satellites
С: 300uF capacitor Right (High Pass) Left
100V, non polorized
Subwoofer Low pass L
Crossover Frequency: 100Hz
C C
L: 6.2mH air core inductor Le те
GTS180 ) |
поп ПП
SPEMES
UNE PREAMP SPEER LE
© nur 6 и \ I eS
© mal | $ y:
‘ac - BERN 1 REM | (©) © | REMOUT
oO и \
u ES e) © m BATHS) | ©) O | ano
. 00 | EST Be
“You may change the subwoofer satellite crossover frequency by using the Inductor and Capacitor values calculated
with the following formulas:
High Pass (Satellite Crossover): : 30,000
Desired crossover Frequency in Hz
620
Desired crossover Frequency in Hz
= New Capacitor Value in WF
Low Pass (Subwoofer Crossover):
= New Inductor Value in mH
Center Channel
Bridged Speaker Connection”
B. Center Channel N Y
GTS180 (+) | go Minimum | CO)
8 Q 45W L-Pad
(Optional But Recommended)
mono ee Ann
SPEAKER
& а © SPEER LEE > OUTPUT AE POWER
EST bh CD
© R Gal: L Y 4 i
a DO т L MN | ©) ©) | Remaur
и _ o a,
® >. © © & I ить | ©) ©) | so
al OV) ©
* Center Channel Speaker Minimum 8 Ohms, Main Speakers
Minimum 4 Ohms When Used Simultaneously. — —
+ — —
Stereo, Non-Bridged yO) O (+)
Speaker Connection”
4 2 Minimum 4 о Minimum
“JBL
18
Audio Input Connections
Line Level Input Connections
¢ Proper wiring between the signal source,
any other components in the system and
the GTS180 will help keep noise levels
in the system low. Use high-quality, low
capacitance shielded wire. Keep the wire
as short as possible. Do not splice
together shielded wires. Do not run
audio signal wires alongside power wires
either for the amp or the vehicle’s stan-
dard power wires for an extended lengih.
When wires are run for long distances,
separate the audio signal wires from
power supply wires or vehicle wiring har-
nesses as much as possible. When sig-
nal wires and power wires must cross,
try to keep them perpendicular. Avoid
routing any wires near accessories such
as ignition control modules, tachometers,
fuel pumps or fan motors.
* The line level inputs of the GTS180
accept standard phono plugs (also
called RCA plugs). The outputs of most
head units, equalizers or crossovers
also accept phono plugs. If another type
of connector is used, adapters or special |
cables may be needed. Proper wire and
connectors can be obtained from any
JBL authorized installation specialist.
+ NOTE: The GTS180 has a built-in
frequency selectable low-pass
(subwoofer) crossover and a
frequency selectable high-pass
(satellite) crossover. Be sure the
crossover switch is properly set for
the chosen system configuration
(See Add-On and Upgrade Steps
section for suggestions). If you have
any questions about how to set this
switch, contact your local JBL dealer.
Speaker Level Input Connections
When speaker level signal is used to drive
the GTS180, the signal goes into the amp
through a special four-wire hamess/
connector (see the “Controls and
Connectors” section). If extension wires are
needed between the head unit output and
the amplifier unit, use conventional speaker
wire. Keep the wiring inside the passenger
and trunk compartments and make the
wires as short as possible. All connections
should be securely crimped or soldered
and insulated with heatshrink tubing.
« Use the color code of the input har-
ness wires and the identification on the
radio/tape deck output wires to be sure
that left and right channels are correct-
ly connected and the positive/negative
polarity of each channel is observed.
For example, the left positive output of
the head unit must be connected to the
left positive input of the GTS180. The
color code for the speaker level input
harness is as follows:
Speaker Level Input Harness
Color Codes
Left (+): White
Left (-): | White with Black Stripe
Right (+): Gray
Right (-): Gray with Black Stripe
Simultaneous Speaker Level +
Line Level
In some systems it may be desirable to
use both the speaker level inputs and
line level inputs simultaneously. For
instance, if you have a stock head
unit in your car you may connect the
speaker level inputs of the head unit to
the GTS180. You may simultaneously
connect a CD player equipped with a
19
volume control to the preamp-level
inputs of the GTS180. The Universal
Interface circuitry of the GTS180 will iso-
late the inputs from each other while
mixing both signals. Therefore switching
from one source to the other is as simple
as turning the unused source off, and
turning the desired source on. No other
switches or relay boxes are needed.
When using this setup it is also possible,
using the wiring setup shown below, to
allow either of the two sources to
remotely turn on the amplifier. Whenever
you are using two sources to turn on the
amplfier it is necessary to put diodes in
series with the remote line as shown in
the diagram below. The Common Sense
turn-on circuit will activate the GTS180
when using the powered source, and the
conventional remote connection of the
preamp-level source will activate the
amp when it is used.
Dual Source Remote Wiring diagram
From Head
Unit #1
Remote or —_ IE
Antenna Output
114001
Diode
To
5T5180
> Remote In/Out
Terminal
1N4001
‚ From Head : !
: Unit #2 sis
ı Remote or || ,
‚ Antenna Output ,
' From Head To
Unit #2 y. 615180
ı Speaker level 2 Speaker Level !
' Output Input with Common:
Sense turn-on ’
Using the Rem-Out Capability
When the GTS180 amplifier is driven by
a BTL head unit into the speaker level
inputs and is remotely turned on with the
Common-Sense circuit instead of a
remote in wire, the "REMOTE IN/OUT"
terminal is turned on to a +12V so that
other amplifiers or signal processors can
be remotely turned on by the GTS180
without the need for an additional remote
on off wire. See diagram below:
Using a remote out connection to turn on other signal
processors or amps.
From the | To
Head Unit GTS180
Speaker level Speaker Level
Output Input with Common
Sense turn-on
From the To the
GTS180 other amplifier
REM IN/OUT or signal processors
terminal remote in terminals
5.5 Input-Mode Switch
This switch is set according to the number
of input channels connected to the amplifi-
er and the desired mode of operation. See
the diagrams on pages 7 and 8 and the
descriptions below for options.
e Conventional Stereo Operation — Set the
input-mode switch to “stereo.” Connect
the preamp-level head unit outputs either
to the two gold line input connectors or
connect the head unit speaker outputs to
the speaker-level inputs. When using
two head units, both the speaker and
preamp-level inputs may be used simul-
taneously. Be sure to maintain left and
right channel consistency. (See the note
in section 5.4 for details.)
e Bridged Mode Operation — To select
bridge mode operation, set the input
mode switch in either the “R” only or
“+В” position. In the “А” position, signal
from the right channel input is fed to both
amplifier channels. In the “L+R” position,
the signal from both channels is summed
internally. When using a single GTS180
for mono mode fed with a stereo signal it
is best to use the “L+R” mode. When
20
using a GTS180 for each channel, or
when feeding a single GTS180 with a
mono signal from an outboard crossover,
use the “R” mode and connect your
source input to the right channel input.
e Simultaneous Stereo + Mono — Set the
Input Mode switch to the stereo posi-
tion. Main speakers are connected
normally to the left and right stereo
outputs, and a center-channel or sub-
woofer speaker is connected as in
bridged mode. Refer to the diagram
on page 18 for connection details.
6. Input Gain Adjustment
Before operating the GTS180, recheck
all wiring connections to make sure they
are correct and secure. Be sure that a
fuse (30 Amp, not included) is installed
in the +12V line near the battery.
Reconnect the negative ground (-) ter-
minal of the battery. Make sure that the
input mode selector, speaker output
crossover switch, crossover frequency
modules, and preamp output crossover
switch are properly set.
Adjusting the Gain
« The setting of the gain control on the
GTS180 is important to ensure proper
performance, low noise levels, and maxi-
mum reliability in the system. As a gener-
al rule, controls on components at the
front-end of the system (source, equaliz-
ers, electronic crossovers, etc.) should be
set as high as possible, with the amplifier
gain control set as low as possible while
still providing adequate volume levels.
Using a high signal level from the source
and a low gain setting on the amplifier will
help keep background noise levels in the
system low.
¢ To adjust a system using a single amplifi-
er, start with the amplifier input gain con-
trols fully counterclockwise. Some head
units have additional output level controls
or switches. Set those to their maximum
position. Set the level controls on any
associated equipment such as equalizers
and electronic crossovers as recommend-
ed by their manufacturers. Set all
Bass/Treble or equalizer controls to their
centered or bypassed positions. While lis-
tening carefully to the system output,
adjust the volume control of the radio/tape
deck to the point where you first begin to
hear audible distortion.* Reduce the level
just to the point where the distortion goes
away. This is the maximum undistorted
output level of your head unit and signal
processors, and should not be exceeded
during use. If audible distortion does not
occur, continue to increase the level until
the head unit is turned all the way up. If
this setting does not provide adequate
volume levels, gradually increase (turn
clockwise) the gain control on the
GTS180 until the system plays as loud as
necessary or when the first signs of distor-
tion are heard.
e When multiple amplifiers are used in the
system, it is best to adjust the gain of the
amplifier driving the main (usually front)
speakers first. Then turn down the head
units volume control to a comfortable
level, and adjust the remaining amplifiers
for the desired system balance. You will
find this easiest to do by adjusting the
amplifiers in the following order: 1) front-
channels, 2) rear-channels, 3) sub-
woofers. Elaborate systems incorporat-
ing tri-or quad-amplification can be com-
plex to adjust. Your local authorized JBL
installation specialist is the best person
to help with such adjustment.
21
* USE CAUTION — excessive distortion
can damage loudspeakers.
7. Other Important
Characteristics
Power Consumption — Operating the
GTS180 when the vehicle is not running
may discharge the battery. At high vol-
umes, the amplifier can draw as much
as 30 amps during brief bursts. After
even a short period of time, this current
drain can discharge the battery to the
point that it will not start the vehicle.
Although power consumption under “no
signal” conditions is less than a few
amperes, even this small power usage
can discharge a battery over several
hours time. When the GTS180 is turned
off, there is no current drawn from the
battery despite the direct-to-battery
power connection.
Overload Protection — The GTS180 incor-
porates elaborate protection circuitry to
prevent damage to the amplifier circuitry
and ensure reliable operation. This circuit-
ry will turn the amplifier off and cause the
power indicator to blink in the event of a
short circuit on the speaker output wiring,
or improper power supply connections. If
the amplifier cycles on and off, or does not
work at all, a problem in installation or an
abnormal electrical condition is indicated.
Check speaker wiring for short circuits or
impedance loads significantly below 2
ohms (4 ohms in bridged mode). Check
the power supply voltage at the input of the
amplifier to be sure that it is normal, be-
tween 11 and 16 volts. Check that the
power wires are not reversed.
lf the GTS180 is operated at very high
power levels in a high ambient tempera-
ture situation, the unit may not be able
to radiate all the heat generated by such
operation. lf the temperature of the am-
plifier reaches a level that could cause
damage, the thermal overload protec-
tion circuit will turn the amplifier and the
power indicator off. It will turn the amp
back on again when it cools off.
Repeated activation of the protection
circuits indicates that the system is
being improperly operated or that the
amplifier should be relocated to an area
that either has a lower ambient temper-
ature or one which allows more air
circulation around the unit.
Fuse Replacement — If the fuse on the
GTS180 must be replaced, DO NOT use
a fuse rated for higher current levels. The
maximum fuse size for the GTS180 is 30
amps. Exceeding the standard fuse size
- or bypassing the fuseholder will void the
warranty and may cause serious damage.
It is extremely rare for this fuse to blow. If
it blows repeatedly, it is most likely that the
amplifier has an internal problem that will
need to be repaired by an authorized ser-
vice center. The only external cause for
this fuse to blow is reversed polarity of the
power wire connections.
8. Maintenance
The GTS180 does not require any regu-
lar maintenance. Periodically checking
the main power supply and grounding
points and terminal connections is advis-
able. Be sure the connections are solid
and corrosion free. Loose or corroded
connections can cause annoying inter-
mittent noise or unusual operational
problems. Do not allow dust to accumu-
late on the amplifier heat sinks. It will
reduce the amplifier's ability to dissipate
heat. Occasional vacuum-cleaning will
prevent dust accumulation.
System 1
Add Power to Main Speakers
Add a GTS to the main
(usually front) outputs of
an existing head unit.
Secondary speakers
(usually rear-fill} connect
to the head unit's internal
amplification.
Next Step:
Add a second GTS to
amplify the other set of
speakers or a subwoofer
(see System 3).
9. Add-On and Upgrade Steps
Front Outputs à
GTS
|
Front
Full-Range
Speakers
LEER В+
+ - +
Ol :
ooL + Rear Outputs
Rear
Full-Range
Speakers
System 2A
Add a Subwoofer (Active)
Use the GTS to drive 1 or 2
subwoofers with the head unit
powering the main speakers.
This is an excellent way to
upgrade a good stock system.
Next Step:
Add power to Front and Rear
Full-Range Speakers.
L-
Front Outputs
Front
Full-Range
Speakers
L+ Вл R+
tor2
Subwoofers
Os : 3
оо HE f Rear Outputs
] RER GTS :
Rear
Full-Range
Speakers
System 2B
Add a Subwooter (Passive)
Use the GTS in
(Horton
Simultaneous Stereo +
Mono mode to drive main
speakers with subwoofers.
A passive crossover is
needed for this as described
on page 17.
Next Step:
Add a second GTS to
«=
E]
=
power subwoofers and
main speakers individually.
Front
“Speakers
L+ R-
+ —
LS A ae
Rear Outputs
Subwoofer
22
23
System 3
Add a Second GTS
Get more power and system
control by adding a second
AE a
Front бриз в 1"
GTS
GTS to power the main
speakers and subwoofers
individually. Use the built-in
crossover to high-pass the
front speakers and low-pass
the subwoofers.
Next Step:
Add power to the Rear Full-
Range Speakers.
Note: For Non-Fading
bass, also connect the
rear-channel head unit
speaker output to the
speaker level input of the
subwoofer GTS.
Front Satellite
Speakers
- + Е- +
- +
1or2
Subwoofers
Rear Outputs
Rear
Full-Range
Speakers
System 4
Add Power to the Rear
Add an amp to the rear
speakers for higher volume
a ET
.
GTS
Frorit Öuiputs E
Preamp output to preamp input
GTS
capability and more control.
Next Step:
Add more subwoofer power.
4 a
Front Satellite
Speakers
Ata
tor2
Subwoofers
te,
\\ Rear Outputs
GTS
Rear Satellite
Speakers
System 5
Add a Second
For the ultimate in
bass output, add a
Fi SLR ET СА,
Subwoofer Amplifier to tiouts E
MU, M,
Semen me la le
Rear Uutputs
GTS
second subwoofer
amplifier for a total
system power of
600 Watts RMS!
Note the cross-
linking of preamp
inputs for the
two subwoofer
"A
amplifiers to provide f}
a
ci
re
ь
non-fading bass.
Next Step:
Add additional L-
р
_ amplifiers in - + - +
bridge-mode to
Subwoofers
the front and
rear main speakers. Then add electronic
crossovers and bi-amp front and rear speakers.
Rear Satellite
Speakers
L-}L+ R-R+
24
10. In Case of Difficulty
Power-on light does not come on
Power light is on, but no sound is
heard from some or all of the speakers
Head unit not on; turn the head unit on.
Ground wire is disconnected or defective;
check for continuity with an ohmmeter
between the amplifier's ground terminal
and a known chassis ground point.
Battery wire is disconnected or defective;
‚check for approximately +12 volts
between the amplifier's battery and
ground terminals.
Blown fuse; check amplifier's fuse
located on the endpanel near the power
connector. If it is blown replace it with an
identical one. If the new fuse blows
immediately, then check all the wiring
connections. If no fault is found, consult
your JBL dealer.
Remote-on wire between the head unit
and the amplifier is disconnected or
defective; check for +12 volts between
amplifiers remote-on input terminal and
the ground input terminal with the head
unit on. |
Amplifier is п thermal protection mode
due to overheating; relocate amp for
more air flow and check wiring.
Incorrect switch settings; make sure
that all switches (input mode and
crossover) are in their correct positions
for your system configuration.
Incorrectly connected or shorted
speaker wires; check for shorts in wiring.
Defective or disconnected audio cables;
check for continuity and replace if
necessary.
Incorrect Gain Adjustment; verify that the
amplifier gain controls are not turned
completely down. lí they are, sound out-
25
Power On light is blinking, indicating a
fault condition, and sound is intermittent
or off
Alternator whine through the audio
system with the engine running
Bass output from speakers too low
put level may be very low and may give
the impression that the system (or part of
the system) is dead.
+ Defective head unit or signal processor;
check each component for proper
wiring and operation.
® Defective GTS180; if there is audio sig-
nal present at the inputs of the amplifier
and there is no output, the GTS180 may
be defective.
* Incorrectly connected or shorted
speaker wires; check for shorts, frayed
wiring, damaged wiring insulation or
incorrect wiring.
* The speaker combination connected to
the amplifier is less than the minimum
requirement; reconfigure speaker con-
nection after consulting with section 3.1
“Speaker Requirements.”
e Amplifier is damaged; consult your JBL
Dealer.
¢ Ground loops; follow the wiring sug-
gestions in the section called “Solving
Noise Problems.” Also, verify that the
chassis grounding point you have chosen
is true ground by checking for continuity
between the chassis ground point and
baitery ground.
¢ Speaker wired out of phase; check for
proper polarity on all speaker wiring
(+ amp terminal to + speaker terminal
and — amp terminal to — speaker
terminal).
If you want to talk to us about any problems, call JBL Customer Service at
1-800-336-4JBL between 9AM and 5PM Eastern time.
26
11. Solving Noise Problems
11.1 System Noise
System noise, generally appearing as
hiss, is usually the result of improper
amplifier input gain adjustment. With
proper setting, your JBL amplifier will
not create this noise, but will amplify
any noise generated ahead of it as part
of the signal. Refer to section 6, “Input
Gain Adjustment” for instructions on
how to minimize this noise.
11.2 Vehicle Noise
Every vehicle has some electrical
“noise” that is generated by the ignition
system, the alternator, the accessories,
and the wiring. High performance audio
equipment is more likely to pick up such
noise than conventional equipment
because it has wide frequency band-
width and high gain (amplification) cir-
cuits. The GTS180 has built-in power
supply filters to help prevent noise
problems. If noise occurs it is probably
the result of improper installation.
The following suggestions will help
you eliminate most noise problems.
Source Noise — Often noise in a system
is picked up by the signal source.
Before attempting to eliminate noise
from the “amp” be sure it is not being
picked up by the signal source and then
passed on to other components. To do
this, connect the signal source output to
an external amplifier which has no other
connection to the vehicle except for the
audio signal leads. A battery-powered
amplified portable speaker, such as
those sold for use with compuiers or
Walkman type portables, works well for
this. Listen to see if the noise is present
in the signal from the source unit. If so,
consult the manufacturer of the source
unit, or your JBL dealer, for help in
reducing this noise. If there is no noise
in this signal, it can be eliminated as the
source of your problems.
Ground Loops — The vast majority of
noise problems are caused by inade-
quate or improper grounding. The head
unit, the amplifier and any other compo-
nents must be grounded to a major
metal member of the vehicle’s frame.
Make sure to choose a solid metal
ground point, as some new vehicles
contain structural elements made of
plastic.
Most often the noise level in the system
will be lower if any amplifiers and signal
processors which do not have isolated
supplies, are all grounded to the same
point on the chassis. Amplifiers such as
the GTS180, which internally isolate the
signal ground connection from the
power ground connection, generally do
not benefit from this. Usually the head
unit does not need to be grounded to
the same point as the rest of the sys-
tem, but in some instances, depending
on the design of the signal processors
involved, grounding signal processors to
the same point as the head unit will also
help. If this does not adequately reduce
the noise level, try another ground point
on the car frame. Because of current
flow patterns within the vehicle chassis,
some ground points are noisier than
others. As a general rule, try to keep
grounds away from the main flow of cur-
rent between the battery and alternator.
For example, in a vehicle with a battery
at the right rear, and an alternator at the
left front, you are most likely to find a
27
quiet ground at the far left rear than
anywhere between the battery and
alternator. In some rare instances with
plastic-bodied vehicles, grounding the
equipment directly to the battery will
provide the best results, although usual-
ly this provides poor results with most
cars and is not recommended.
In complex systems involving compo-
nents from different manufacturers, it
helps to know the type of power sup-
plies used in each component. For low-
level signal processors such as equaliz-
ers or electronic crossovers, a manufac-
turer may use either a power supply
which is isolated through a DC-to-DC
converter, or a simple regulated supply
from the +12V vehicle battery. The
important characteristic to know is how
well the power ground is isolated from
the signal ground (phono-plug shield) in
each component. Many simple signal
processors or low-powered amplifiers
have no isolation. These can be identi-
fied by a direct connection from power
ground to the shield of the RCA jacks
(measured with an ohmmeter with no
other connections present). For these
components, the best ground connec-
tion may be one where the power
ground wire is not connected at all! The
RCA cables will provide the ground con-
nection to the source unit. Please note
that this is only appropriate for units
which draw less than 500mA of current.
Higher power units of this type, such as
amplifiers, are best connected with their
ground wires connected directly to the
chassis of the head unit.
The trickiest grounding task is created
when some components of this type are
mixed with other components using iso-
lated supplies. For this type of system,
the following grounding scheme will
usually work:
1. Connect the head unit chassis to a
solid vehicle ground using a short,
heavy gauge wire (AWG #10).
Do not connect this to the vehicle’s
wiring harness, but go directly to a
metal part of the vehicle.
2. Connect all signal-processor
grounds directly to the head unit
chassis at the same point. Run each
wire individually. Due to wire resis-
tance, connecting multiple wires to a
single wire, then running the single
wire to the head unit, is not the
same!
3. Connect all amplifier grounds
directly to the vehicle chassis but
not necessarily to the same point
as the head unit.
Power-line noise — The built-in power
supply filter of the amplifier makes
external filters unnecessary. In some
cases, power supply noise can enter the
system through the head unit power
supply or the supply of an equalizer or
other signal processor. Putting a filter
on the head unit or signal processor
power supply input may then be helpful.
Using a portable powered speaker as
described in the “Source Noise” section
can help you isolate an individual com-
ponent which may be sensitive to this.
Start at the head unit, and work back,
checking each component individually.
Power wires carrying high currents may
induce noise in nearby signal wires.
Make sure that power wires and signal
wires do not run together for long dis-
28
UBL
tances. When power and signal leads
must cross, they should cross at right
angles. If you suspect that power line
noise is being induced in the signal
leads, you can repeat the test for source
noise described previously, but perform
the test at the amplifier end of the signal
cables. One power wire that it will be
impossible to stay away from is the
vehicle chassis. The chassis is one
giant ground wire! Use high quality
shielded cables or a balanced-line sys-
tem for the long front-to-rear signal runs
to reduce the likelihood of noise pickup
from this source.
Other Noise Sources — Common noise
problems will be solved by proper
grounding and power supply connec-
tions. However, there are impulse type
noise sources which may require sup-
pression at the noise source. Many
noise suppression devices (such as
spark plug and coil lead suppressors
and rotor and coil bypass capacitors)
are available at auto parts or car stereo
stores. There are also noise suppres-
sors that can be connected directly to
the alternator that are effective in some
situations. The use of any such sup-
pressor should be discussed with a JBL
authorized installation specialist after
the basic grounding scheme and power
connections are confirmed correct.
Certain vehicles are particularly “noisy,”
especially models that have solid state
ignition systems or that have non-metal
bodies. Such vehicles may require elec-
trical noise suppression devices which
are not normally required.
Antenna — A common noise problem is
generated by a “ground loop” produced
by the antenna shielded cable being
grounded at both the antenna mounting
point and at the head unit input. In this
instance, insulate the antenna ground
from the chassis of the vehicle at the
antenna mounting point so the antenna
shield is grounded only at the radio's
antenna input. Commercial antenna
ground-loop isolators are also available.
Switching Noise — The GTS180 has а
highly developed switching power sup-
ply which generates some RF interter-
ence as a result of its switch-mode
operation. Although this is internally fil-
tered and shielded by the GTS180
chassis, some unusually sensitive
installations may pick up switching
noise, especially when listening to weak
AM radio stations. If this unusual situa-
tion occurs, one of the following installa-
tion corrections will typically eliminate
the problem. 1) Relocate the amplifier to
a position farther away from the radio ог.
radio antenna. 2) Move the electrical
ground of the head unit and/or amp to a
different point on the vehicle’s chassis.
3) Keep the amplifier power supply
wiring away from the radio or antenna
wiring. 4) Wrap the +12 volt power sup-
ply wires for the radio/tape deck with
metallized shielding tape or ground
braid, and ground the tape to the
chassis of the vehicle.
29
12. Specifications
Power Output
(20Hz — 20KHz, |
14.4V Battery Voltage)
Signal to Noise Ratio
Frequency Response
Damping Factor
Slew Factor
Line Level Input Sensitivity
(For Rated Power)
Speaker Level Input Sensitivity
(For Rated Power)
Preamp Output Sensitivity
Preamp Input:
Speaker Input:
Maximum Preamp Output Voltage
Line Level input Impedance
Speaker Level Input Impedance
Minimum Speaker Impedance
Single Ended (Non-Bridged)
Bridged
60 Watts x 2 —
(4 Ohms, 0.05% THD)
90 Wrrs x 2
(2 Ohms, 0.08% THD)
180 Watis x 1 |
(4 Ohms, 0.08% THD)
100dBA
10Hz - 50kHz (+0, -1dB)
20Hz — 20kHz (+0, -0.1dB)
>200
>5
100mV - 4V RMS
(500mV at Center Detent)
200mV - 8V RMS
(1V at Center Detent)
AV in for 4V out
AV in for 2V out
AV
10k Ohms
15 Ohm or 100k Ohm
(Selectable by Internal Jumpers)
2 Ohms
4 Ohms
30
Specifications
Built-in Electronic
Crossover Frequency
and Slope
Bass Boost Frequency
and Magnitude
Power Requirement
Fuse Size
Size (Е x W x H)
Weight
Speaker Level Input
Mating Connector
18dB per Octave Low-Pass
Filter, Frequency Chips
Available from 50-5kHz
Factory Seiting: 80Hz
18dB per Octave High-Pass
Filter, Frequency Chips
Available from 50-5kHz
Factory Setting: 80Hz
+4dB at 40Hz
11 to 16V DC
Negative Ground
30 Amp ATC Type Fuse
11-1/8" x 9-1/4" x 2"
(282 mm x 235 mm x
51 mm)
8 Ibs 12 oz (4 kg)
Molex Mini-Fit Jr.
# 39-01-2045-P
Metal Pins: 39-00-0039
Staple or clip your original bill of sale here. Y
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