Infinity 5760a Reference Series Service Manual page 8

Power Amplifier
I
NSTALLATION AND
SETTING DBO ™ (310a, 610a and 1210a)
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.
DBO HP FREQ Control HP FREQ
(adjusts cut-off
frequency)
20Hz 100Hz
dB
0
-3
-6
-9
-12
20 80 Freq. (Hz)
S ( .)
ETUP CONT
DBO BOOST Control BOOST
(adjusts boost amount
at cut-off frequency)
dB MIN
12
6
0
-6
-12
20 80 Freq. (Hz)
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.
MAX
7
Ref5760a