Input Sensitivity Controls; Remote Level Control (Optional); Filter Controls; Infrasonic Filter - JL Audio XD1000/1v2 Owner's Manual

INPUT SENSITIVITY CONTROLS

Input Sens.
to match the source unit's output voltage to the
input stage of the XD1000/1v2 for maximum
clean output. Rotating the control clockwise will
result in higher sensitivity (louder for a given
input voltage). Rotating the control counter-
clockwise will result in lower sensitivity (quieter
for a given input voltage).
To properly set the amplifier for maximum
clean output, please refer to Appendix A (
page
) in this manual. After using this procedure,
12
Input Sens.
downward if this is required to achieve the
desired system balance.
Do not increase any "Input Sens." setting for
any channel(s) of any amplifier in the system
beyond the maximum level established during
the procedure outlined in Appendix A (page 12).
Doing so will result in audible distortion and
possible speaker damage.

FILTER CONTROLS

Most speakers are not designed to reproduce
the full range of frequencies audible by the human
ear. For this reason, most speaker systems are
comprised of multiple speakers, each dedicated
to reproducing a specific frequency range. Filters
are used to select which frequency range is sent
to each section of a speaker system. The division
of frequency ranges to different speakers can be
done with passive filters (coils and/or capacitors
between the amplifier outputs and the speakers),
which are acceptable and commonly used
for filtering between mid-range speakers and
tweeters. Filtering between subwoofer systems
8 | JL Audio - XD1200/1v2 Owner's Manual
and satellite speaker systems is best done with
active filters, which cut off frequency content at
the input to the amplifier. Active filters are more
stable than passive filters and do not introduce
extraneous resistance, which can degrade
subwoofer performance.
The active low-pass filter built into the
above its filter frequency, so that the system's
subwoofers do not reproduce any audible
midrange content.
This serves to improve tonal balance
and to avoid distortion. Correct use
of the filter can substantially improve
the fidelity of your audio system.
2) LP Filter Operation: The low-pass filter in the
Filter Freq.
systems). The filter also features the ability to
12dB
24dB LP
Filter Mode/Slope
the vehicle, different slopes may be required
to produce a smooth transition to the mid-
bass speakers in the system. Experiment to
find the slope which best matches the acoustic
requirements of your system.
Tuning Hint: A trunk mounted sub whose
backseat often benefits from the 12 dB/octave
slope which lets more upper bass content pass
through. A sub that fires directly into the
listening environment is more likely to benefit
from a 24 dB/octave slope.
Note:
You should always listen to the system carefully to
determine the best choice as vehicle acoustics and
other factors play a big role in choosing the most
appropriate filter slope.
3) Precise Frequency Selection: The filter
frequency markings on the front panel of
the amplifier are for reference purposes and
are generally accurate to within 1/3 octave
or better. If you would like to select the filter
frequency with a higher level of precision,
consult Appendix B (page 13) of this manual.
This chart gives you a more accurate frequency
for each of the forty detented positions of the
frequency selection control. This method can
be very useful if the amplifier is mounted in
a location where you can't see the front panel
markings easily.
4) Defeating the LP Filter:
can also be defeated completely, by switching
LP Filter Mode/Slope
Off
an external active crossover in the system.
With the internal crossover turned off, the

INFRASONIC FILTER

Infrasonic Filter
This filter is designed to conserve amplifier power
and protect subwoofer systems, without audibly
degrading the sub-bass output.
With ported enclosures, the use of the
Infrasonic Filter
protect the speaker(s) from excessive excursion
below box tuning.
With sealed enclosures, the use of the filter
is less necessary, but can still help protect the
speaker system from excessive excursion.
Infrasonic Filter
Off
switch. This bypasses all signal from flowing
through the circuit.

REMOTE LEVEL CONTROL (OPTIONAL)

With the addition of the optional Remote
subwoofer volume from the front of the vehicle
Remote Level Control
using a single-line, four-wire phone line splitter
and multiple phone cables.
When connected to the amplifier, the
clockwise rotation, the audio will mute
completely. At full clockwise rotation the level
connected at all. In other words, it operates
strictly as a level attenuator.
9