GRAND
TOURING
®
SERIES
GTO327
GTO427
GTO527
GTO627
GTO637
GTO6427
GTO6527
GTO6527S
GTO6537
GTO837
GTO8627
GTO927
GTO937
multielements
owner’s manual
THANK YOU
for purchasing a JBL®Grand Touring®Series automotive
speakers. We’ve organized this manual to make your
installation as simple and trouble-free as possible.
Please read it thoroughly before proceeding. Remember
to keep your sales receipt and this manual in a safe
place so both are available for future reference.
INSTALLATION WARNINGS AND TIPS
ABOUT THESE
INSTRUCTIONS
Installation of automotive stereo components
can require extensive experience with a
variety of mechanical and electrical
procedures. Although these instructions
explain how to install Grand Touring Series
multielement speakers in a general sense,
they do not show the exact installation
methods for your particular vehicle. If
you do not feel you have the necessary
experience, do not attempt the installation
yourself – instead, ask your authorized
JBL car audio dealer about professional
installation options.
LOUD MUSIC AND HEARING
Playing loud music in an automobile can
hinder your ability to hear traffic as well as
permanently damage your hearing. The
maximum volume levels achievable with
JBL speakers, combined with high power
amplification, may exceed safe levels for
extended listening. We recommend using
low volume levels when driving. JBL
accepts no liability for hearing loss, bodily
injury or property damage as a result of use
or misuse of this product.
REAR DECK PRECAUTION
In some cars, the fuel tank may be located
directly beneath the rear deck. Before
installation, make sure there is adequate
speaker basket clearance before
considering this location.
INSTALLATION TIPS
• Always wear protective eyewear when
using any tools.
• Turn off all audio components and other
electrical devices before you start.
Disconnect the (–) negative lead from your
vehicle’s battery.
• Keep speakers in their package until final
installation. When moving a speaker,
always rest it with the cone or dome
facing up. Never use force to install
any speaker.
• Check clearances on both sides of a
planned mounting surface before drilling
any holes or installing any screws.
Remember that the screws can extend
behind the surface.
• At the installation sites, locate and make a
note of all fuel lines, hydraulic brake lines,
vacuum lines and electrical wiring. Use
extreme caution when cutting or drilling in
and around these areas.
• Before drilling or cutting holes, use a utility
knife to remove unwanted fabric or vinyl
to keep material from snagging in a drill bit
or saw.
• For door installations, check the clearance
with the windows throughout the range of
the window’s travel, and verify that a
mounted speaker will not interfere with
the window crank or power window
mechanism.
• If mounting speakers elsewhere, check for
clearance around rear deck torsion bars,
glove box or other structural elements.
• Do not mount speakers where they will
get wet.
INSTALLATION
UNIPOINT™ROTATING
TWEETER
Figure 1. Turn the angled tweeter on the
GTO527, GTO627, GTO6527, GTO8627 and
GTO927 to aim the sound at the listener.
TWEETER LEVEL CONTROL
Figure 2. Move the tweeter level control
switch on the GTO527, GTO627,
GTO637, GTO6527, GTO6537, GTO837,
GTO8627, GTO927 and GTO937 to
select 0dB (reference) or +3dB.
2