GTb 8 A
USA
Please read these operating instructions before using
the equipment for the fi rst time.
Safety Notes
Please observe the following safety notes during the instal-
lation and connection.
–
Disconnect the negative terminal of the battery before
carrying out installation and connection work.
–
Observe the vehicle manufacturer's safety instructions
(regarding airbags, alarm systems, trip computers,
vehicle immobilisers).
–
When you drill holes, ensure that you do not damage any
vehicle components.
–
The cross sections of the positive and negative cables
must not be less than 1.5 mm
–
An incorrect installation can result in malfunctions of the
electronic vehicle systems or your car sound system.
Installation and connection instructions
With respect to accident safety, the GTb 8 A
must be secured in a professional way.
When selecting the installation location,
select a dry location that off ers suffi cient air
circulation for cooling the amplifi er.
The GTb 8 A must not be installed on rear
shelves, rear seats or other locations that are
open to the front.
The amplifi er power cable must be fi tted with a fuse no more
than 30 cm from the battery to protect the vehicle battery in
case of a short circuit between power amplifi er and battery.
The fuse of the amplifi er protects only the amplifi er, not the
vehicle battery.
Switching on/off
One of the special features of the GTb 8 A is its automatic
switch-on.
The subwoofer box automatically switches on if a music
signal is received.
If there is no music signal for more than 60 seconds, the
GTb 8 A automatically switches off .
Connection (see page 27 / Fig. 1)
8
Connection
is connected to the positive pole of the
7
battery and connection
control of the GTb 8 A should ideally be a two-channel con-
trol, either via the preamplifi er outputs or the loudspeaker
outputs of the car sound system. A control solely via the right
or left channel is also possible since the low-frequency por-
tion of the music is generally identical on both channels.
The preamplifi er outputs are connected to the cinch (RCA)
;
sockets
of the subwoofer box via a shielded sound
cable.
With control via the loudspeaker outputs, the input connec-
5
6
tions of pos.
/
are fed to the closest loudspeaker cables
(front or rear) on the left and right. They are separated and
26
2
(A.W.G. 16).
to negative vehicle ground. The
connected to the input connections. The polarity of the
+ or - connections must be observed. Bridge output stages
(BTL) can also be connected directly without an additional
adapter.
TIM function:
For car sound systems with activated TIM function, the
GTb 8 A must be controlled via the loudspeaker outputs
of the car sound system and not via the RCA inputs (see
page 27 / Fig. 1 of the operating instructions).
1
Upper cut-off frequency
2
Phase position
3
Input sensitivity
4
Connector cable
5
Right loudspeaker input
6
Left loudspeaker input
7
- Ground
8
+ Battery
9
7.5 A fuse
:
Status display (Power)
;
Preamplifi er inputs
Settings
The following control setting is recommended as basic set-
ting before putting the device into operation: Sensitivity
3
(gain) Pos.
to minimum, phase Pos.
1
over) Pos.
to approx. 80 Hz. Switch on the device and
select a musical piece with distinctive bass playback.
Increase the volume of your stereo system to the desired
volume level. Now slowly increase the gain control
you can hear a clear amplifi cation of the bass level. Next, use
1
the crossover control
to select a fi lter setting that provides
a well-contoured bass. You may have to alternately optimise
3
the gain control setting
A droning bass with excessive volume requires a fi lter setting
with a low frequency.
The phase switch must be set so that the bass is integrated
into the acoustic pattern as best as possible and not recog-
nisable as an individual source.
Also check your settings of the GTb 8 A with the bass control
fully open and, if necessary, with activated loudness. An
overloading of the subwoofer box by selecting an excessive
3
amplifi cation (pos.
) results in a distorted playback and can
damage the loudspeaker.
Recycling and disposal
Please use the return and collection systems avail-
able to dispose of the product.
Subject to changes!
2
to 0°, fi lter (cross-
3
1
and the fi lter setting
.
until