!

I M P O RTA N T

BRIDGING CONSIDERATIONS

 

 

STATUS INDICATOR LIGHTS /

SERVICING YOUR JL AUDIO AMPLIFIER

If you connect a load higher than 4Ω nominal per channel in stereo mode (or 8Ω in bridged mode), power will drop by half with every doubling of impedance above 4Ω stereo / 8Ω mono. If you connect a load lower than 1.5Ω nominal per channel in stereo mode (or 3Ω in bridged mode, the amplifier protection circuitry activates a “safe” mode which reduces amplifier power to protect the circuitry from failure (the yellow “Low Ω” LED lights to

Bridging is the practice of combining the output of two amplifier channels to drive a single load. When bridged, each channel produces signals of equal magnitude, but opposite polarity. The combined output of the two channels provides twice the output voltage available from a single channel. The 450/4v2 has been designed for bridging of its channel pairs without the need for input inversion adaptors.

PROTECTION CIRCUITRY

There are three status indicator lights on the top of the amplifier. These are as follows:

1)iPowerw Green): lights to indicate that the amplifier is turned on and operating normally.

2)iThermalw Red): lights to indicate that the amplifier has exceeded its safe operating temperature, putting the amplifier into a self-

If your amplifier fails or malfunctions, please

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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

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to service the amplifier yourself or through

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void the warranty, but may result in the creation

indicate that this has happened). See page 13

ction

CH 3 & 4 Speaker Outputs

Sens.

 

for details.

 

 

 

 

!

I M P O RTA N T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Left

Right

 

 

 

 

 

 

Speaker loads below 1.5Ω nominal per channel

 

 

75W (1.5-4Ω)

75W

 

H 4

Bridged: 150W x 1 (3-8Ω)

in stereo or 3Ω nominal in bridged mode are

 

 

ght)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

not recommended and may cause the amplifier

 

 

 

 

 

 

 

 

 

 

 

output to distort excessively.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5PCSJEHFBQBJSPGDIBOOFMTVTFUIFiLeft +w

 

 

 

 

BOEiRight wTQFBLFSDPOOFDUPSTPOMZUIFiLeft

 

 

 

 

wBOEiRight +wSFNBJOVOVTFE 5IFODPOOFDU

 

 

 

 

a mono signal to both left and right RCA inputs

 

 

 

 

for that channel pair. This requires an RCA

 

 

 

 

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XB-CLRAICY-1F2M (sold separately). When bridged, each channel pair will deliver optimum power into a 3-8Ω load. Operating bridged channel pairs into a load lower than 3Ω is not recommended.

Because a bridged pair of channels requires that both channels receive input, you need to connect both left and right RCA inputs to the bridged channel pair’s inputs. Connection of only one RCA input will result in reduced power output, increased distortion and can cause the

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left and right RCA inputs.

protection mode, which reduces the power output of the amplifier. The red light will shut off and the amplifier will return to normal, full-power operating mode if the heat sink temperature drops back to a safe level.

3)iLow Ωw Amber): lights to indicate that the impedance of the speaker load connected to the amplifier is lower than the optimum load impedance range for the amplifier. When this light is on, a protection circuit engages and reduces the power output of CH 1&2 or CH 3&4, depending on which channel is experiencing the problem. The amber indicator will also light when a short-circuit is detected in the speaker wiring (this can be a short between the positive and negative speaker wires or between either speaker wire and the vehicle chassis). This can be used to diagnose a short-circuit by only connecting one of the amplifier sections at a time (CH 1&2 and CH

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connect the section that is experiencing the problem and turn the volume up.

There is only one condition that will shut down an undamaged 450/4v2 completely… If battery voltage drops below 10 volts, the entire amplifier will shut itself off. The green

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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, have your charging system inspected to make sure it is working properly. For information on troubleshooting this amplifier, refer to Appendix C (page 24).

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

12 JL Audio - 450/4v2 Owner’s Manual

13

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JL Audio 450/4V2 owner manual Status Indicator Lights Servicing Your JL Audio Amplifier, Protection Circuitry