Diamond D400.1 - Manual (Page 15)

15
Adjustment of Built-In Crossover (All Models)
Placing the switch in the FULL position sets the amplifier to Full Range. This setting allows
ALL frequencies to pass to the speakers. (Not available on D600.1, & D1000.1). Placing the
switch in the HP or LP position activates the crossover.
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.
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 (D400.1, D600.1, & D1000.1)
After setting the input gain adjustment and crossover, you may choose to add a small
amount of “boost” in the low frequency region. The bass boost frequency is variable
between 30Hz and 125Hz (D600.1, & D1000.1 ONLY). 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 EQ 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 +12dB. 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
assumptions 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.