JL Audio G4500 owner manual Rear pairs of stereo outputs, Subwoofer Level Control Only

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 14), you can fine tune filter frequencies and attenuate either pair of channels to achieve proper balance. For precise filter frequency information refer to Appendix B (page 15).

Bi-Amplified System with one G4500 in four-channel mode and a separate subwoofer amplifier

This configuration requires that the separate subwoofer amplifier has a built-in low-pass filter. All JL Audio amplifiers have this feature.

In this configuration, channels 1&2 of the G4500 will drive front component speakerswith high- pass filtering. Channels 3&4 will drive

rear component speakers in stereo, also with high-pass filtering. The separate amplifier will drive the subwoofer system with low-pass filtering (80 Hz is a good starting point).

Input connection options for a bi-amplified system with one G4500 and a separate subwoofer amplifier 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 is connected to the “CH 1 (Left)” and “CH 2 (Right)” inputs of the G4500 (select “1&2” on the “CH 3&4 Input From” switch).

Connect the subwoofer amplifier inputs to the preamp outputs of the G4500 (Select “1&2” on the “Pre-Outs Input From” switch. Alternatively, the G4500 can receive its input from the subwoofer amplifier’s preamp output set to “full-range” mode (if applicable).

Result: the relative level of the LF and front and rear HF channels will be fixed by the G4500’s “Input Sens.” settings (as well as the subwoofer amplifier’s 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 front

and rear pairs of stereo outputs.

Input Connections: one stereo pair of source unit outputs is connected to the “CH 1 (Left)” and “CH 2 (Right)” inputs of the G4500 (select “1&2” on the “CH 3&4 Input From” switch).

The second stereo pair of source unit outputs is connected to the subwoofer amplifier inputs.

Result: with this option, the user has the ability to fade the level of the subwoofer amplifier’s input relative to the HF channels, but cannot control front-to-rear fading of the HF channels. The relative level of the front and rear HF channels will be fixed by the G4500’s

“Input Sens.” settings and will not be user adjustable from the front of the vehicle.

C)Subwoofer Level Control Only:

Required: a source unit or processor with left, right 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 G4500 (select “1&2” on the “CH 3&4 Input From” switch). The source unit’s dedicated subwoofer output is connected to the subwoofer amplifier inputs.

Result: with this option, the user has the ability to control the absolute level of the subwoofer channel relative to the HF channels, but cannot fade the front and rear HF channels relative to each other.

Set the subwoofer amplifier’s “Input Sens.” with the source unit’s subwoofer level control set at 3/4 of full output.

D)Front to Rear HF Fading and Subwoofer Level Control:

Required: a source unit or processor with front and rear pairs of stereo outputs plus a dedicated subwoofer output.

Input Connections: one stereo pair of source unit outputs is connected to the “CH 1 (Left)” and “CH 2 (Right)” inputs of the G4500.

The second stereo pair of source unit outputs is connected to the “CH 3 (Left)” and “CH 4 (Right)” inputs of the G4500 (select “Discrete” on the “CH 3&4 Input From” switch). The source unit’s dedicated subwoofer output is connected to the subwoofer amplifier inputs.

Result: with this option, the user has the ability to fade the front and rear HF channels relative to each other and also has the ability to control the absolute level of the subwoofer channel relative to the HF channels.

Set the subwoofer amplifier’s “Input Sens.” with the source unit’s subwoofer level control set at 3/4 of full output.

Crossover Setup for Bi-Amplified System with one G4500 and a separate subwoofer amplifier:

Once the input and preamp output sections have been configured appropriately, go to the “Channel 1 & 2 Controls” and “Channel 3 &

4 Controls” You will set both control sections identically to start:

Select “HP” (high-pass) on the “Filter Mode” switch and an appropriate “Filter Freq.” (80 Hz is a good starting point). Make these adjustments to both control sections.

After proper adjustment of the G4500’s “Input Sens.” controls, and the subwoofer amplifier’s input sensitivity controls, you can fine tune filter frequencies and attenuate either pair of channels to achieve proper balance. For proper adjustment of the “Input Sens.” controls of the G4500 use the method shown in Appendix A (page 14). For precise filter frequency information for the G4500 refer to Appendix B (page 15). Refer to the subwoofer owner’s manual for proper adjustments.

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