JL Audio A6450 Advanced Rollback Thermal protection, Low-Voltageprotection, System Configurations

AMPLIFIER STATUS INDICATOR LIGHTS & PROTECTION CIRCUITRY

There are two status indicator lights on the input / control end of the amplifier.

1)“Power” (Green): lights to indicate that the amplifier is turned on and operating normally.

2)“Protect” (Red): Indicates that the amplifier protection circuitry has been activated to prevent product failure due to a short-circuit or a dangerously low impedance connected to the amplifier output(s). Connecting the speaker outputs to an impedance lower than 2 ohms stereo (4 ohms bridged) will cause this protection mode to activate. When this protection mode is activated, the amplifier will reduce it maximum power output to protect its circuitry, which will manifest itself as increased distortion. When the problem is corrected, the amplifier will return to normal operation.

Advanced Rollback Thermal protection

Unlike conventional thermal protection systems, which shut down an amplifier when it overheats, this system protects the amplifier by gradually reducing power output if the amplifier’s safe operating temperature is exceeded. The amplifier will continue to operate and return

to normal power output once its temperature returns to a normal range.

Low-Voltage protection:

If the car’s supply voltage drops below 10 volts, the entire amplifier will shut itself off to protect its internal circuitry. The green “Power” indicator will turn off when this occurs. The amplifier will turn back on when voltage climbs back above 10 volts. This may happen in a rapid cycle when bass-heavy program material causes a weak charging system to dip below 10 volts momentarily. If this is happening in your system, turn your audio system off and have your power wiring, ground connections and charging system inspected.

SERVICING YOUR JL AUDIO AMPLIFIER

If your amplifier fails or malfunctions, please return it to your authorized JL Audio dealer so that it may be sent in to JL Audio for service. There are no user serviceable parts or fuses inside the amplifier. The unique nature of the circuitry in the JL Audio amplifiers requires specifically trained service personnel. Do not attempt

to service the amplifier yourself or through unauthorized repair facilities. This will not only void the warranty, but may result in the creation of more problems within the amplifier.

If you have any questions about the installation or setup of the amplifier not covered in this manual, please contact your dealer or technical support.

JL Audio Technical Support:

(954) 443-1100

9:00 AM – 5:30 PM (Eastern Time Zone)

Monday - Friday

SYSTEM CONFIGURATIONS

The A6450 is a flexible amplifier, well-suited for a multitude of system configurations. In this section, the most likely configurations 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 A6450 is designed to work as the only amplifier in a bi-amplified system.

Bi-Amplified System with the A6450

In this configuration, channels 5&6 of the A6450 will drive subwoofers (stereo 75W x 2 at 2 ohms or bridged 150W x 1 at 4 ohms) with low- pass filtering. Channels 1&2 and channels 3&4 will drive component speakers in stereo (75W x 4 at 2 ohms) with high-pass filtering.

Input connection options for a bi-amplified system with one A6450 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 each split with a “Y-Adaptor” allowing the left signal to be sent to the “CH 1 (Left)” and “CH 3 (Left)” inputs and the right signal to be sent to the “CH 2 (Right)” and “CH 4 (Right)” inputs of the A6450 (select “Sum” on the “Input Mode” switch in the “Channel 5 & 6 Controls” section).

Result: the relative level of the LF and HF channels will be fixed by the A6450’s “Input Sens.” settings and will not be user adjustable from the front of the vehicle.

B)Fade Front vs. Rear with no Subwoofer Level Control:

Required: a basic source unit or processor with two pairs of stereo outputs.

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

to the “CH 3 (Left)” and “CH 4 (Right)” inputs of the A6450 (select “Sum” on the “Input Mode” switch in the “Channel 5 & 6 Controls” section).

Result: the relative level of the LF and HF channels will be fixed by the A6450’s “Input Sens.” settings and will not be user adjustable from the front of the vehicle.

C)Fade Subwoofer Level vs. HF Level: Required: a basic source unit or processor with

two pairs of stereo outputs.

Input Connections: the first stereo pair of source unit outputs each split with a “Y-Adaptor” allowing the left signal to be sent to the “CH 1 (Left)” and “CH 3 (Left)” inputs and the right signal to be sent to the “CH 2 (Right)” and “CH 4 (Right)” inputs of the A6450. The second stereo pair of source unit outputs is connected to the “CH 5 (Left)” and “CH

6 (Right)” inputs (select “Discrete” on the “Input Mode” switch in the “Channel 5 & 6 Controls” section).

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.

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