GTb 8200 A
5
8
Right loudspeaker input
9
Left loudspeaker input
:
Power-on indicator (Power/Protect)
;
Automatic switch-on
<
Preamplifi er inputs
Voltage supply
We recommend a minimum cross section of 1.5 mm
2
.
Route commercially available plus cables to the battery
and connect via fuse holder.
Use cable glands for holes with sharp edges.
Securely fasten commercially available minus cables to a
noise-free earth point (chassis screw, chassis metal) (not
to the minus pole of the battery).
Scrap the contact surfaces of the earth point until they
are bright and grease with graphite grease.
Connection
6
is connected to the positive pole of the
battery and connection
4
to negative vehicle ground.
The control of the GTb 8200 A should ideally be a two-
channel control, 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 portion of the music is generally identical
on both channels.
Integrated fuse
The fuse integrated in the amplifi er protects the output stage
and the entire electrical system in case of a malfunction. If a
replacement fuse is used, never bridge fuses or replace them
with a type with higher current.
Audio inputs
You can select between 2 diff erent audio inputs;
Cinch (RCA)
High level (loudspeaker connections)
Use only one of the audio inputs; otherwise, it may lead to
audio interferences.
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-
tions of pos.
8
/
9
are fed to the closest loudspeaker cables
(front or rear) on the left and right. They are separated and
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.
Switching on/off
A special feature of the GTb 8200 A is its automatic switch-on.
It is set via the INPUT switch
;
:
RCA
Switching on/off via the car sound system. The remote
connection
5
of the GTb 8200 A must be connected with
a switchable 12-V power supply (e.g. switching output of
the car sound system).
–
–
–
–
–
–
–
–
HIGH
Switching on/off via the loudspeaker connections
8
/
9
.
The subwoofer box automatically switches on if a music
signal is received. If no music signal is received for more
than 60 seconds, the GTb 8200 A automatically switches
off .
GAIN control
The GAIN control
3
is used to adjust the input sensitivity of
the power amplifi er to the output voltage of your car sound
system preamplifi er output.
The adjustment range is from 0.3 V to 19 V.
If a car sound system of a third party manufacturer is con-
nected, the input sensitivity must be adjusted corresponding
to the manufacturer data.
A few important explanations in this context:
By turning the control clockwise, the input sensitivity of the
amplifi er and, therefore, also the volume increases. However,
this is not a volume control; no further amplifi er output
can be achieved in the end position, even if it may sound
like that at the beginning. The system merely increases the
volume faster if the volume control of the car sound system
is turned up.
X-OVER frequency control
The X-OVER control
1
allows setting the desired entry
frequency.
Example:
At a setting of 150 Hz, the amplifi er has a frequency range
of 30 Hz to 150 Hz.
Settings
The following control setting is recommended as basic
setting before putting the device into operation: Sensitiv-
ity (GAIN) Pos.
3
to minimum, PHASE Pos.
2
to 0°, fi lter
(X-OVER) Pos.
1
to approx. 80 Hz. Switch on the device and
select a musical piece with distinctive bass playback.
Increase the volume of your car sound system to the desired
volume level. Now slowly increase the GAIN control
3
until
you can hear a clear amplifi cation of the bass level. Next, use
the X-OVER control
1
to select a fi lter setting that provides
a well-contoured bass. You may have to alternately optimise
the sensitivity setting
3
and the fi lter setting
1
.
A droning bass with excessive volume requires a fi lter setting
with a low frequency.
The phase switch
2
must be set so that the bass is inte-
grated into the acoustic pattern as best as possible and not
recognisable as an individual source.
Also check your settings of the GTb 8200 A with the bass
control fully open and, if necessary, with activated loudness.
An overloading of the subwoofer box by selecting an exces-
sive amplifi cation (pos.
3
) results in a distorted playback and
can damage the loudspeaker.
Power-on indicator
Green LED:
Output stage on, regular operating status.
Red LED:
Output stage is electronically switched off due to an error.
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GTb8200A_13LG.indd 5
GTb8200A_13LG.indd 5
19.11.2013 10:34:36 Uhr
19.11.2013 10:34:36 Uhr
