JL Audio XD700/5 Car Amplifier User Manual


 
7
Input Voltage Range:
The XD700/5’s input sections are designed to
accept signal voltages from 100mV – 4V. This
will accommodate all preamp level signals and
many speaker level signals.
To use speaker-level sources, simply splice the
speaker output wires of the source unit onto a
pair of RCA plugs for each input pair. (or use
JL Audio part XD-CLRAIC2-SW) No “line
output converter” is needed in most cases.
If you find that the output cannot be reduced
sufficiently with a direct speaker level signal
applied to the amplifier, you may use a “line
output converter” to reduce the signal level.
INPUT SENSITIVITY CONTROLS
The controls labeled “Input Sens.” located in
each channel section can be used to match the
source unit’s output voltage to the input stage of
each pair of amplifier channels 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
14) in this manual. After using this procedure,
you can then adjust any or all “Input Sens.
levels 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 14).
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 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 filter built into each channel section
of the XD700/5 can be used to eliminate
potentially harmful and/or undesired frequencies
from making their way through the amplifier
sections to the speaker(s). This serves to improve
tonal balance and to avoid distortion and possible
speaker failure. Correct use of these filters can
substantially increase the longevity and fidelity of
your audio system.
1) “Filter Mode” Controls: The XD700/5
employs 12dB per octave filters for each pair
of main channels (one high-pass filter for
channels 1&2 and another high-pass / bandpass
filter for channels 3&4. The Subwoofer Channel
provides a low-pass filter with the option of
12dB or 24dB / octave slopes. Each of these
filters can be controlled or defeated completely
by way of the three-position “Filter Mode”
switches in each Channel Section: