Filter
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13
a sharper filter slope that more aggressively
attenuates frequencies above the selected “Filter
Freq.” setting. Neither setting is inherently
“better”, but in general, the shallower “12dB”
setting is more desirable for a subwoofer having
to fire from a trunk into the cabin of a sedan or
coupe. The sharper “24dB” setting is typically
better in a hatchback, SUV or wagon application.
Experiment to find the slope setting that results in
the smoothest subwoofer to midbass transition.
Next, turn your attention to the “CH 3 &
4” Controls and select “BP” (bandpass) on
the “Filter Mode” switch. A bandpass filter is
actually composed of two filters (one high-pass
and one low-pass), which in combination allow a
defined “band” of frequencies to pass through the
amplifier channels and onto the speakers. These
are ideal for actively filtered mid-bass or mid-
range speakers in automotive sound systems.
Now that you have engaged Bandpass Mode
for Channels 3 & 4, select an appropriate “Filter
Freq.” (again, 80 Hz is a good starting point).
The Filter Frequency you are adjusting with this
control is the high-pass portion of the bandpass
filter. The low-pass portion is automatically set by
the tweeter channel’s “Filter Freq.” adjustment
(CH 1 & 2). The low-pass portion of the bandpass
filter will always track with the CH 1 & 2 “Filter
Freq.” setting.
Finally, turn your attention to the “CH 1
& 2” Controls and select “x10” (high-pass)
on the “HP Filter Mode” switch. This switch
position multiplies the indicated “Filter
Freq.” value by a factor of 10, so that an
indicated frequency of 500 Hz is actually a
filter frequency of 5000 Hz (5 kHz). The filter
slope for this section is fixed at 12dB/octave.
Now, select an appropriate “Filter Freq.” for
your tweeters (5000 Hz is a good starting point).
Before attempting any lower frequency settings,
consult the documentation for the tweeters you
are using and make sure you will not be driving
the tweeters with frequencies lower than they are
designed to handle. JL Audio mobile component
tweeters should not be operated with Filter
Frequencies lower than 3 kHz.
After proper adjustment of the “Input
Sens.” controls for both main channel
pairs and the subwoofer channel using the
method shown in Appendix A (page 14),
you can fine tune filter frequencies and
attenuate either pair of channels to achieve
proper balance. For precise filter frequency
information refer to Appendix B (page 15)
To operate two XD700/5’s in Tri-Amplified
mode (one for left channel and the other for right
channel), set the “Input Mode” switches of both
amplifiers in “2 Ch.” mode, and apply the left
channel signal to both the left and right inputs of
the first amplifier’s Channel 1 & 2 Inputs, using
an RCA y-adaptor with one female and two male
ends. Then apply the right channel signal to both
the left and right inputs of the second amplifier’s
Channel 1 & 2 inputs, using a second RCA
y-adaptor with one female and two male ends.