Boston Acoustics GT-4100 Car Amplifier User Manual


 
fuse
Tuning - Front and Rear Speakers
9
Tuning The Amplifier - Front and Rear Speakers
6) Input Sensitivity Control
Starting with the front channels, slowly rotate the control clockwise (refer to the diagram on page 5) until maxi-
mum undistorted playing level is heard from the speakers. Listen closely for bottoming from the speakers. If detect-
ed, rotate the input sensitivity control counterclockwise until it is eliminated. Repeat for the rear channels.
7) Crossover Controls
To achieve higher undistorted playing levels from the both the front and rear speakers, the highpass crossover must
b
e engaged. Starting with the front channels, rotate the crossover control fully clockwise (refer to the diagram on
page 5). The highpass crossover point is now set at 350Hz. Rotate “Q-Tune
Control fully counterclockwise (front
channels only). Move crossover switch to the right (ON) position.
Slowly rotate the input sensitivity control clockwise until maximum undistorted playing level is heard from the
speakers. Listen closely for bottoming from the speakers. If detected, rotate the input sensitivity control counterclock-
wise until it is eliminated. Slowly rotate the highpass crossover control counterclockwise while listening for
bottoming. You are lowering the crossover point, which means that more bass signal is being sent to the speakers. If
bottoming is detected, rotate the input sensitivity control counterclockwise until it is eliminated and/or rotate the
Highpass crossover control clockwise to raise the crossover point. Repeat for the rear channels.
8) Q-Tune
Control (Front Channels Only)
Once the highpass crossover point has been determined, use the Q-Tune
control (refer to the diagram on page 5)
to increase the bass information centered around the crossover point.
Setting the Q-Tune
control is done in conjunction with setting the levels on the input sensitivity and highpass
crossover frequency controls. You may find while setting the Q-Tune
that over-excursion may be detected in the
front speakers; lowering the Q-Tune
input sensitivity or raising the highpass crossover point will eliminate this.
Minor adjustments to each setting are required to fine-tune the system.
Setting the Q-Tune
is a subtle process. It is recommended that the Q-Tune
setting be left in the 0.7 position and
adjusted only after the input sensitivity and highpass crossover ranges are known. Small adjustments to the Q-Tune
setting are all that are required to fine-tune the system.
4-Channel Operation Wiring Configuration Diagram