Adjustment of Built-In Crossover (All Models)
Placing the switch in the HP position sets the amplifier to the High Pass mode, enabling frequencies above the cutoff point to pass.
Placing the switch in the LP position sets the amplifier to the Low Pass mode, enabling frequencies below the cutoff point to pass.
Placing the switch in the OFF position sets the amplifier to Full Range, preventing any crossover ad- justment. This setting allows ALL frequencies to pass to the speakers. (Not available on D1 400.1).
Turn the crossover adjustment knob all the way down. With the system playing, turn the crossover adjustment knob up slowly until the desired crossover point is achieved.
Adjustment of the Bass EQ (Bass Boost) on D1 400.1
After setting the input gain adjustment and crossover, you may choose to add a small amount of “boost” in the low frequency region. This bass boost adjustment is FIXED at 45HZ. Remember that the Bass Boost feature will not fix a poorly designed subwoofer enclosure or subwoofers that didn’t sound good to begin with.
1)Make sure any bass boost or low frequency equalization from the source unit is set to OFF or FLAT. If you have other outboard signal processors with equalization, you should use those to add boost first and leave the amplifier’s bass boost alone.
2)While playing the same musical selections used during the gain setting process, slowly increase the level of the Bass EQ. You should be able to notice a demonstrable change between 0 and +6dB. If you do not notice much difference, then it will not serve any benefit to increase the boost further.
3)If the boost has audible benefits without adding appreciable distortion, find a level that suits your taste. Remember: it’s much easier to construct the right subwoofer enclosure for your listening preferences than relying on a bass boost control to do the job!
Remember that the Bass EQ feature has an optional dash mounted control included with the amplifier that will function as an attenuator between the maximum level set at the amplifier and 0dB of attenuation. It will not add boost beyond the level you choose at the amplifier.
Troubleshooting
It’s imperative that you read the manual fully to eliminate the possibility of mistakes made from assump- tions about how you “think” the amplifier might work versus how it’s recommended to be installed. If the amplifier does not appear to be working, check obvious things first such as blown fuses, incorrect wiring configurations, poor or loose connections, crossover, Bass EQ, and gain controls set incorrectly, etc. These elements are the most common cause of initial problems, so take your time and double check all of your work before assuming there’s a serious problem.
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