INFINITY 611A
Manual de Servicio

Power Amplifier

Reference 610a/611a

INSTALLATION AND SETUP (CONT.)
SETTING DBO� 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
(adjusts cut-off frequency)
dB 0 -3 -6 -9 -12 20 80 Freq. (Hz)
20Hz 100Hz

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.

HP FREQ

DBO BOOST Control
(adjusts boost amount at cut-off frequency)
dB 12 6 0 -6 -12 20 80

BOOST

MIN

MAX

Freq. (Hz)

6