JL Audio G4500 owner manual Appendix a, Necessary Equipment, Nine-Step Procedure, Input Sections

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Appendix A:

Input Sensitivity Level Setting Following the directions below will allow the

installer to adjust the input sensitivity of each amplifier channel pair simply and easily in just a few minutes using equipment which is commonly available in installation bays.

Necessary Equipment

Digital AC Voltmeter

CD with a sine-wave test tone recorded at

0 dB reference level in the frequency range to be amplified for that set of channels

(50 Hz for subwoofer channels, 1 kHz for a midrange application). Do not use attenuated test tones (-10 dB, -20 dB, etc.).

The Nine-Step Procedure

1)Disconnect the speaker(s) from the amplifier’s speaker output connectors.

2)Turn off all processing (bass/treble, loudness, EQ, etc.) on the source unit, processors (if used) and amplifier. Set fader control to center position and subwoofer level control to 3/4 of maximum (if used to feed the G4500).

3)Switch the Input Voltageswitch to Lowand turn the Input Sens.control all the way down.

4)Set the source unit volume to 3/4 of full volume. This will allow for reasonable gain overlap with moderate clipping at full volume.

5)Using the chart on this page, determine the target voltage for input sensitivity adjustment according to the nominal impedance of the speaker system connected to the amplifier outputs.

6)Verify that you have disconnected the speakers before proceeding. Play a track with an appropriate sine wave (within the frequency range to be amplified by the G4500) at 3/4 source unit volume.

7)Connect the AC voltmeter to the speaker output connectors of the amplifier. If the channel pair is operating in stereo, it is only necessary to measure one channel. If bridged, make sure you test the voltage at the correct connectors (L+ and R–).

8)Increase the Input Sens.control until the target voltage is observed with the voltmeter.

9)Once you have adjusted the G4500 to its maximum low-distortion output level, reconnect the speaker(s). The Input Sens.controls can now be adjusted downward if the amplifier requires attenuation to achieve the desired system balance.

Do not increase any Input Sens.setting for any amplifier channel or channel pair in the system beyond the maximum level established during this procedure. Doing so will result in audible distortion and possible speaker damage.

It will be necessary to re-adjust the Input Sens.for the affected channels if any equalizer boost is activated after setting the

Input Sens. with this procedure. This applies to any EQ boost circuit, including source unit tone controls or EQ circuits. EQ cuts will not require re-adjustment.

Nom.

Target AC Voltage

Impedance

Stereo

Bridged

 

 

 

 

17..8 V

26..8 V

17..8 V

25..6 V

17..8 V

24..6 V

17..3 V

not recommended

15..8 V

not recommended

 

 

 

Appendix B: 

Precise Frequency Selection Chart

“Filter FREQ” AMP Filter

Detent Panel Actual

Number Marking Freq.

Full counter-clockwise: 53

01 .

. . . . . . . . . . . . . . . . .

53

02 .

. . . . . . “50”

.53. . . .

03 .

. . . . . . . . . . . . . . . . .

53

04 .

. . . . . . . . . . . . . . . . .

54

05 .

. . . . . . . . . . . . . . . . .

54

06 .

. . . . . . . . . . . . . . . . .

55

07 .

. . . . . . . . . . . . . . . . .

55

08 .

. . . . . . “55”

.56. . . .

09 .

. . . . . . . . . . . . . . . . .

56

10 .

. . . . . . . . . . . . . . . . .

57

11 .

. . . . . . . . . . . . . . . . .

58

12 .

. . . . . . . . . . . . . . . . .

59

13 .

. . . . . . . . . . . . . . . . .

62

14 .

. . . . . . “60”

.65. . . .

15 .

. . . . . . . . . . . . . . . . .

65

16 .

. . . . . . . . . . . . . . . . .

66

17 .

. . . . . . . . . . . . . . . . .

70

18 .

. . . . . . . . . . . . . . . . .

73

19 .

. . . . . . . . . . . . . . . . .

77

20 .

. . . . . . “80”

.81. . . .

21 .

. . . . . . . . . . . . . . . . .

84

22 .

. . . . . . . . . . . . . . . . .

88

23 .

. . . . . . . . . . . . . . . . .

94

24 .

. . . . . . . . . . . . . . . . .

101

25 .

. . . . . . . . . . . . . . . . .

104

26 .

. . . . . .“120”. . . . . . . . . 115. . . .

27 .

. . . . . . . . . . . . . . . . .

118

28 .

. . . . . . . . . . . . . . . . .

128

29 .

. . . . . . . . . . . . . . . . .

137

30 .

. . . . . . . . . . . . . . . . .

146

31 .

. . . . . . . . . . . . . . . . .

164

32 .

. . . . . .“150”. . . . . . . . . 177. . . .

33 .

. . . . . . . . . . . . . . . . .

193

34 .

. . . . . . . . . . . . . . . . .

197

35 .

. . . . . . . . . . . . . . . . .

209

36 .

. . . . . . . . . . . . . . . . .

213

37 .

. . . . . . . . . . . . . . . . .

216

38 .

. . . . . .“200”. . . . . . . . . 218. . . .

39 .

. . . . . . . . . . . . . . . . .

225

 

Full-clockwise: 225

 

Appendix C:

G4500 Specifications

General Specifications:

Recommended Fuse Value: 50A

Recommended Fuse Type: AFS, AGU or MaxiFuse™

Input Sections:

No. of Inputs: Two Stereo Pairs

Input Type: Differential-balanced with RCA jack inputs

Input Range: Switchable from 200mV - 2V RMS to 800mV - 8V RMS

Amplifier Section:

Amplifier Topology: Class A/B with patented Absolute Symmetry™ dual N-Channel MOSFET output design Power Supply: Unregulated MOSFET switching type Rated Power at 14.4V with less than

1% THD+Noise (20Hz - 20 kHz) Stereo, all channels driven:

80W RMS x 4 @ 4 ohms, 125W RMS x 4 @ 2 ohms Bridged, all channels driven:

160W RMS x 2 @ 8 ohms, 250W RMS x 2 @ 4 ohms Rated Power @ 12.5V with less than

1% THD + Noise (20Hz - 20 kHz) Stereo, all channels driven:

60W RMS x 4 @ 4 ohms, 90W RMS x 4 @ 2 ohms Rated Power Bridged, all channels driven:

120W RMS x 2 @ 8 ohms, 180W RMS x 2 @ 4 ohms Signal to Noise Ratio: >104 dB referred to rated power (A-weighted, 20 Hz-20 kHz noise bandwidth) Frequency Response: 10 Hz - 25 kHz (+0, -1dB) Damping Factor: >200 @ 4 ohms per ch../50 Hz, >100 @ 2 ohms per ch.. /50 Hz

Slew Rate: ± 22V/µs

Amplifier Filter:

Filter Type: State-variable, 12dB/octave Butterworth with continuously variable cutoff frequency selection from 50-200 Hz..

Configurable as Low-Pass or High-Pass.. Defeatable..

Preamp Output:

Pass-through type, buffered..

Switch-selectable to pass signal from CH 1&2 inputs only or from all four inputs (summed)..

Dimensions(LxWxH):

13.8" x 9.25" x 2.50" (350mm x 235mm x 63.5mm)

Due to ongoing product development, all specifications are subject to change without notice..

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JL AUDIO G4500

JL AUDIO G4500

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Contents If you have any questions regarding the instructions in this Safety Considerations Cooling Efficiency ConsiderationsSerial Number Stupid Mistakes to AvoidPower Connections Product DescriptionMany vehicles employ small 10 AWG Fuse RequirementsInput Section Input Voltage RangeLow position on the Input Voltage Input Sensitivity Controls Bass BOOST CONTROLS Pre-OUTS Speaker Outputs Do not do thisSYSTEM CONFIGURATIONS Rear pairs of stereo outputs Subwoofer Level Control OnlyNine-Step Procedure Appendix B  Precise Frequency Selection ChartAppendix C G4500 Specifications General Specifications DimensionsLxWxHMy amplifier doesn’t turn on My amplifier turns on, but there is no outputINSTALLATION NOTES Limited Warranty Amplifiers USA If you need service on your JL Audio productJL Audio, Inc International Warranties