JL Audio XD400/4 - Handbuch (Seite 9)

9
ENGLISH
remote leVel control (oPtional)
With the addition of the optional Remote
Level Control (HD-RLC), you can control the
volume of one, or both channel pairs of the
XD400/4 from the front of the vehicle. This is
useful for subwoofer level control, rear channel
level control, center-channel level control or even
as a master volume control for the system.
The HD-RLC connects to the jack labeled
“Remote Level Control” on the Connection Panel
of the amplifier using a standard telephone cable
(supplied with the HD-RLC). If desired, multiple
XD (and HD) amplifiers can be controlled from
a single HD-RLC controller using a simple phone
line “splitter” and multiple phone cables.
When connected to the amplifier, the
HD-RLC operates as follows. At full counter-
clockwise rotation, the audio will mute
completely. At full clockwise rotation the level
will be the same as if the HD-RLC was not
connected at all. In other words, it operates
strictly as a level attenuator.
“Remote Level Mode” Switch: This switch
allows you to assign the operation of the
HD-RLC to one, or both pairs of channels. In
the “All” position, the HD-RLC knob will affect
all three channel pairs equally. In the “3&4”
position, only the level of channels 3 and 4 will
be affected by the HD-RLC knob (Channels 1 &
2 will not).
Preouts
The XD400/4 incorporates a pass-through
preamp output section, so that additional
amplifiers can be easily added to the system. This
pass-through pre-amp output can be configured
two different ways using the switch labeled
“Preouts From”.
1) “1&2”: The preamp output delivers the same
signal that is connected to the CH 1&2 Inputs.
This mode is useful for feeding a subwoofer
amplifier when the XD400/4 is being used to
drive front and rear speaker systems. In this
mode, the preamp output signal will depend
only on the input signal level of CH 1&2,
allowing Channels 3&4 to be faded without
affecting the subwoofer level. If CH 1&2 is
faded in this mode, the signal level of the
preamp output will change accordingly.
2) “Sum”: When the XD400/4 is being used
to drive front and rear speaker systems, this
preamp output mode will deliver a summed
front/rear stereo signal to a subwoofer amplifier,
while permitting fading of the front and
rear speaker systems from the source unit.
This method prevents a loss of signal to the
subwoofer amplifier when the system is faded to
the front or the rear by the head unit.
Note: Any signal delay between the front and rear
channels can result in a cancellation of signals
within certain frequency ranges when using the
“Sum” position. If you experience a loss of bass
output in the “Sum” position, compared to the
“1&2” position, you are likely dealing with a
delayed signal in either the front or rear outputs
of the source unit. If the front to rear delay is
desirable for other reasons or if it cannot be
defeated at the source unit, we recommend that
you use the “1&2” position.
Note: In either mode, the preamp output signal is
not affected by any crossover filter selected (if the
input signal is full-range, the preamp output will
be full-range).