PRO POWER
TM
Professional-Grade Automotive Component Speaker System Owner’s Manual C508GTi C608GTi
Important: Installation of automotive stereo
components can require extensive experi-
ence performing a variety of mechanical
and electrical procedures. Although these
instructions explain how to install a GTi
component system in a general sense, they
do not show the exact installation method
for your particular car. If you don’t feel you
have the necessary tools or experience, ask
your authorized JBL car audio dealer about
professional installation options.
Warning: Playing loud music in your
automobile can permanently damage your
hearing as well as hinder your ability to
hear traffic. We recommend listening at
low volume while driving. JBL accepts
no liability for hearing loss, bodily injury
or property damage
resulting from use or
misuse of this product.
A Note About System Performance
For the best performance possible, the
GTi components should be used with a
two-channel amplifier with output power
of at least 50W RMS per channel. The
passive
crossover contains impedance-
compensating
circuitry and has been
computer-optimized for the flattest possible
frequency response with the tweeter flush-
mounted, on-axis with the listener. The
combined responses of the speakers and
passive crossover constitute a 4th-order
Linquitz-Riley
acoustic alignment and
cannot be duplicated
with any electronic
crossover currently available for car audio
use. Consequently, bi-amping a GTi
component system with an electronic
crossover is not recommended.
Speaker Placement
Figures 1–4 show possible speaker
placements in the order of most desirable
to least desirable. Kick-panel mounting will
provide the best staging and imaging in
most vehicles.
Tweeter Installation
TWEETER
on dash
WOOFER
in factory-
door location
TWEETER
on kick panel
WOOFER
in factory-
door location
TWEETER
and
WOOFER
on kick panel
WOOFER
in factory-
door location
TWEETER
in high/forward
location on door
Fig 1
Fig 3
Fig 2
Fig 4
Figure 1.
Mounting the woofer and tweeter in the
kick panels
Figure 2.
Mounting the woofer in the door and the
tweeter in the kick panel
Figure 3.
Mounting the woofer and tweeter in the
doors
Figure 4.
Mounting the woofer in the door and the
tweeter in the dash
–
+
–
+
Figure 5.
Surface-mounting the tweeter:
first push in (1), then turn (2)
Figure 6.
Flush-mounting the tweeter:
first push in (1), then turn (2)
02
The Official Brand of Live Music
Woofer Installation
Figure 7.
Mounting the C508GTi or C608GTi woofer
where there is no factory speaker location.
To mount the C508GTi in factory locations,
omit the grille and grille tray.
Figure 8.
Mounting the C608GTi woofer in
standard 5-1/4" holes (in many
Japanese and American automobiles)
Figure 9.
Mounting the C608GTi woofer in
165mm holes (in many European
and American automobiles)
Electrical Connections and Crossover Adjustments
Figure 10.
Connecting the speakers and the amplifier to
the crossover
Figure 11.
Adjust the crossover using the jumpers
provided
DECLARATION OF CONFORMITY
We, Harman Consumer International
2, route de Tours
72500 Chateau-du-Loir
France
Emmanuel Millot
Harman Consumer International
Chateau-du-Loir, France 7/01
declare in own responsibility, that the products
described in this owner’s manual are in compliance
with technical standards:
EN 50081-1:1992
EN 50082-1:1997
03
PRO POWER
TM
JBL Consumer Products • 250 Crossways Park Drive, Woodbury, NY 11797
1-800-336-4JBL (4525) www.jbl.com
©2001 JBL, Incorporated • JBL is a registered trademark of JBL, Incorporated
Part No. C508/C608GTiOM7/01
Specifications
C508GTi C608GTi Tweeter
5-1/4" Professional-grade 6-1/4" Professional-grade
automotive component automotive component
speaker system speaker system
Power handling (peak) 500W 600W n/a
Power handling (RMS) 125W 150W n/a
Frequency response 58Hz – 21kHz 50Hz – 21kHz n/a
Nominal impedance 4 ohms 4 ohms n/a
Sensitivity (2.83V/1m) 88dB 89dB n/a
Crossover 4th-Order Linquitz-Riley Acoustic, 3500Hz, 24dB/octave n/a
Cut-out diameter 4-5/8" (118mm) 5-1/8" (131mm) 1-3/4” (45mm)
Mounting depth 2-3/8" (61mm) 2-11/16" (69mm) 1” (25.4mm)
Thiele and Small Parameters
Revc
3.00 3.50 3.14
Levc 0.16 0.25 0.01
Sd 0.0086 0.0117 0.0006
BL 6.00 6.69 2.22
Vas 3.34 7.90 0.0016
Cms 322.0 405.0 31
Mms 12.07 18.21 0.46
Mmd 11.61 17.48 0.452
Fs 80.7 58.61 1320
Qms 6.51 9.01 1.8
Qes 0.51 0.52 2.463
Qts 0.47 0.50 1.04
Top-plate thickness 0.2” (5.08mm) 0.25” (6.35mm) n/a
Voice-coil length 0.5” (12.7mm) 0.65” (16.51mm) n/a
Voice-coil diameter 2” (50.8mm) 2” (50.8mm) 1” (25.4mm)
Xmax 1/8” (3.44mm) 1/8” (3.44mm) n/a
