JL Audio XD400/4, XD600/1 owner manual Remote Level control Optional, PreOUTS

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).

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