7
STATUS LEDs
Clip:
Indicates the amplifier is being overdriven,
and your speakers may be in danger. This
should blink only on musical peaks, and not
be on constantly.
Power:
Indicates the amplifier is on.
Protection:
Refer to “Troubleshooting” for specific
indications.
Figure 15.
LED status.
SETTING DBO (311a, 611a and 1211a)
The Dynamic Bass Optimizer (DBO) is used to
enhance low-frequency reproduction in a vehicle.
Conventional bass-boost circuits only increase
bass at a fixed frequency, and cause the amplifier
to consume considerable power. The DBO allows
you to adjust the frequency (20Hz – 80Hz) as well
as the boost level (up to 12dB; see Figure 14),
allowing you to fine-tune the bass in your system
to optimize performance.
For sealed enclosures, the DBO can be used
to enhance the lower bass region of sealed
enclosures.
For bigger/fuller bass, adjust the HP FREQ
between 35Hz and 45Hz; adjust the BOOST
control according to your preference.
For tighter-sounding bass, adjust the HP FREQ
between 45Hz and 55Hz; adjust the BOOST
control according to your preference.
For vented enclosures, the DBO should be used
as a subsonic filter to reduce overexcursion
of the woofers. Set the HP FREQ control 10Hz
below the tuning frequency of the enclosure
(e.g., 25Hz for a box tuning of 35Hz); adjust the
BOOST control to taste. This will conserve
amplifier power typically wasted on frequencies
below the tuned frequency of the enclosure.
For infinite-baffle applications, set the HP FREQ to
the speaker’s Fs value (reducing overexcursion of
the woofer); adjust the Boost control to taste.
Figure 14.
Frequency-response curves show
typical DBO control ranges.
I
NSTALLATION AND
S
ETUP
(
CONT
.)
-9
-6
-3
0
-12
20
80
Freq. (Hz)
dB
DBO HP FREQ Control
(adjusts cut-off
frequency)
-6
0
6
12
-12
20
80
Freq. (Hz)
dB
DBO BOOST Control
(adjusts boost amount
at cut-off frequency)
HP FREQ
100Hz
20Hz
BOOST
MAX
MIN
-9
-6
-3
0
-12
20
80
Freq. (Hz)
dB
DBO HP FREQ Control
(adjusts cut-off
frequency)
-6
0
6
12
-12
20
80
Freq. (Hz)
dB
DBO BOOST Control
(adjusts boost amount
at cut-off frequency)
HP FREQ
100Hz
20Hz
BOOST
MAX
MIN
• PROBLEM:
No audio (POWER LED is off).
CAUSE and SOLUTION:
No voltage at BATT+ and/or REM terminals, or
bad or no ground connection. Check voltages
at amplifier terminals with VOM.
• PROBLEM:
No audio (PROTECT LED flashes every
4 seconds).
CAUSE and SOLUTION:
DC voltage on amplifier output. Amplifier may
need service; see enclosed warranty card for
service information.
• PROBLEM:
No audio (PROTECT LED is on).
CAUSE and SOLUTION:
Amplifier is overheated. Make sure amplifier
cooling is not blocked at mounting location;
verify that speaker-system impedance is within
specified limits.
• PROBLEM:
No audio (PROTECT and POWER LEDs flash).
CAUSE and SOLUTION:
Voltage less than 9V on BATT+ connection.
Check vehicle charging system.
• PROBLEM:
No audio (PROTECT LED is on).
CAUSE and SOLUTION:
Voltage greater than 16V or less than 8.5V on
BATT+ connection. Check vehicle charging
system.
• PROBLEM:
Distorted audio.
CAUSE and SOLUTION:
Input sensitivity is not set properly, or amplifier
or source unit is defective. Check INPUT LEVEL
setting, or check speaker wires for shorts or
grounds.
• PROBLEM:
Distorted audio (PROTECT LED flashes).
CAUSE and SOLUTION:
Short circuit in speaker or wire. Remove
speaker leads one at a time to locate shorted
speaker or wire, then repair.
• PROBLEM:
Music lacks “punch.”
CAUSE and SOLUTION:
Speakers are not connected properly. Check
speaker connections for proper polarity.
T
ROUBLESHOOTING