System Configurations, Bi-AmpLIFIED SYSTEMS

SYSTEM CONFIGURATIONS

The XD400/4 is a flexible amplifier, well- suited for a multitude of system configurations. In this section, the most likely configurations for a system with a single XD400/4 are explained in detail.

Once you have selected your desired configuration, you can use the amplifier panel drawing on pages 18 & 19 to mark the required switch positions for easy reference.

Bi-AmpLIFIED SYSTEMS

Bi-amplified systems are defined as systems in which separate amplifier channels drive low- frequency (LF) and high-frequency (HF) speakers and are separately filtered to send appropriate frequency ranges to each speaker system.

The most common application of bi-amplification in mobile audio is to drive a subwoofer system from one or more amplifiers or channels and component speakers from separate amplifiers or channels.

The XD400/4 can be configured to drive a bi-amplified system by itself or with a separate subwoofer amplifier.

Bi-Amplified System with one XD400/4 In this configuration, channels 3&4 of the

XD400/4 will drive subwoofers (stereo or bridged) with low-pass filtering. Channels 1&2 will drive component speakers in stereo with high-pass filtering.

Input connection options for a bi-amplified system with one XD400/4 are as follows:

A)No User Adjustability:

Required: a basic source unit or processor with one pair of stereo outputs.

Input Connections: a single pair of stereo source unit outputs connected to the “CH 1 (Left)” and“CH 2 (Right)” inputs of the XD400/4 (select “2 Ch.” on the “Input Mode” switch).

Result: the relative level of the LF and HF channels will be determined by the XD400/4’s “Input Sens.” settings and will not be user adjustable from the front of the vehicle.

B)Fade Subwoofer Level vs. HF Level Required: a source unit or processor with two

pairs of stereo outputs.

Input Connections: the first stereo pair of source unit outputs is connected to the “CH 1 (Left)” and “CH 2 (Right)” inputs of the XD400/4.

The second stereo pair of source unit outputs is connected to the “CH 3 (Left)” and “CH 4 (Right)” inputs (select “4 Ch.” on the “Input Mode” switch).

Result: in this mode, the user has the ability to fade or control the level of the LF channels relative to the HF channels via the source unit’s fader control without exceeding the maximum clean output level set by each amplifier section’s “Input Sens.” controls.

C)Subwoofer Level Control Only: Required: a source unit or processor with

one pair of stereo outputs and dedicated subwoofer outputs.

Input Connections: the main stereo pair of source unit outputs is connected to the “CH 1 (Left)” and “CH 2 (Right)” inputs of the XD400/4. The source unit’s dedicated subwoofer output is connected to the “CH

3 (Left)” and “CH 4 (Right)” inputs (select “4 Ch.” on the “Input Mode” switch).

Result: in this mode, the user has the ability to control the absolute level of the LF channels relative to the HF channels.

Set the “Input Sens.” in the “Channel 3 & 4 Controls” section with the source unit’s subwoofer level control set at 3/4 of full output. See Appendix A (page 14) for details.

Crossover Setup for Bi-Amplified System with one XD400/4:

Once the input sections have been configured appropriately, go to the “Channel 3 & 4 Controls”. Select “LP” (low-pass) on the “Filter Mode” switch and an appropriate “Filter Freq.” (80 Hz is a good starting point).

Next, turn your attention to the “Channel 1 & 2 Controls” and select “HP” (high-pass) on the “Filter Mode” switch and an appropriate “Filter Freq.” (again, 80 Hz is a good starting point).

After proper adjustment of the “Input

Sens.” controls for both channel pairs using the method shown in Appendix A (page

12 JL Audio - XD400/4 Owner’s Manual