Crossover Controls - JL Audio HD750/1 Owner's Manual

The output of the amplifier decreases for a
given input voltage when the "Input Range"
switch is placed in the "High" position. The
output increases with the switch in the "Low"
position. While this may sound counter-
intuitive, it is correct as described.
"input sens." control
Located to the left of the "Input Voltage"
switch is a rotary control labeled "Input Sens.".
Once the appropriate "Input Voltage" range has
been selected, this control 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 C (pages 18, 19) in this manual.
After using this procedure, you can then adjust
the relative level by adjusting the input sensitivity
downward, if it requires attenuation to achieve
the desired system balance.
Do not increase the "Input Sens." setting for
any amplifier in the system beyond the maximum
level established during the procedure outlined in
Appendix C (pages 18, 19). Doing so will result in
audible distortion and possible speaker damage.
10 | JL Audio - HD750/1 Owner's Manual

crossoVer controls

Crossovers are groups of electronic filters
designed to control the frequency ranges
that each speaker in a system will be tasked
with reproducing. Proper crossover setup is
critical to sound quality and reliability.
The HD750/1 has one filter, which can be
configured as a high-pass filter (attenuates low
frequencies) or as a low-pass filter (attenuates
high frequencies). Additionally, the user can
select from a shallow (12dB/octave) filter slope
or a more aggressive (24dB/octave) slope.
1) "Filter Mode" Control: this switch allows you
to defeat or configure the filter into one of two
filter types:
"Off": Defeats the filter completely, allowing
the full range of frequencies present at the
inputs to feed the amplifier. This is useful
for systems utilizing outboard crossovers or
requiring full-range reproduction.
"HP" (High-Pass): Configures the filter
to attenuate frequencies below the selected
filter frequency. Useful for connection of
component speakers in a bi-amplified system.
"LP" (Low-Pass): Attenuates frequencies
above the selected filter frequency.
Useful for connection of subwoofer(s)
in a bi-amplified system.