Adjustments

CROSSOVER FREQUENCY SELECTION

The low-pass continuously adjustable crossover frequencies are selectable between 40Hz and 200Hz. Adjust the setting according to your speaker component specification or to your particular preference.

Figure 12: Crossover Frequency Adjustment

SUBSONIC FREQUENCY SELECTION

The advantage of a subsonic filter is to maximize the amplifiers output when a specifically tuned subwoofer system is needed. For example, if your subwoofer system is designed to play 40Hz - 80Hz only, the amplifier distributes 100% of its power for only that frequency range. The subsonic frequency settings are 20Hz or 40Hz. Select the setting according to your prefered subwoofer sys- tem specification or to your particular preference.

Figure 13: Subsonic Frequency Adjustment

INPUT SENSITIVITY ADJUSTMENT

The Input Sensitivity Control is located on the Input Panel. The objective of input sensitivity adjust- ment is to match the output of the source unit with the input of the amplifier. The output voltage of individual source units can vary. For example, some source units have an output of 200 mV and others have 5 Volts or more. To cater to these variations, the DB amplifier has an adjustable input sensitivity level that ranges from 100 mV to 5 volts.

Adjusting this control requires some experimenting. Basically, you want all the gain at the begin- ning of the system, NOT at the end (amplifier). Turn your headunit UP and keep your amplifier gains at the minimum possible setting (counter-clockwise). This will give you the best sound and signal-to-noise ratio.

Besides better sonic reproduction, proper input sensitivity also helps to prolong the reliability span of your amplifier by eliminating excessive internal temperature generated by incompatible source unit output and amplifier input.

Note : Turning the input gain UP does NOT indicate MORE power. Just MORE noise. The input gain control IS NOT a power control. REMEMBER that the input gain control has nothing to do with the power output of the amplifier.

COUSTIC.COM

Figure 14: Input Sensitivity Control

1.Turn the Input Sensitivity Control all the way down (counter clockwise).

2.Set the volume control of the source unit to approximately 2⁄3 of its maximum output.

3.Turn the balance control of the source unit to its center position.

4.Leave the tone (bass/treble) controls at their usual position.

5.Play a CD or tape track with wide dynamic range.

6.Use the Bass Boost Control to enhance the bass performance (if desired).

7.To locate the optimum input sensitivity setting, ask the person assisting you to turn the Input Sensitivity Control clockwise until audio distortion starts to develop. Turn the sensitivity control counter clockwise slightly to minimize the distortion.

8.If you constantly switch between CD/tape and radio, you will need further adjustment since radio output level differs from that of CD or tape. In this case, you need to locate a balanced sensitivity setting which is best for both the output level of radio and that of CD or tape.

BASS BOOST CONTROL (BOOST)

Select a boost level between 0dB and +18dB to enhance the bass performance for your sound system. BASS BOOST is NOT free! Every 3dB of boost costs you twice as much in power. Make sure to set the final gains . . . after setting the Bass Boost to work best with your subwoofer/ enclosure combination. More is NOT always better!

SETTING UP & USING REMOTE SUBWOOFER GAIN CONTROL (R S)

If you are using the R S control, make sure to take this into account during set-up procedures of the subwoofer amplifier. You should set the system up with the R S plugged in, and with the level knob turned all the way down (counter clockwise).