JL Audio J2320.4 Appendix a, Necessary Equipment, Nine-Step Procedure, Amplifier Section

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 connected, set the amplifier’s Remote Bass Control at maximum (full clockwise).

3)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) at 3/4 source unit volume.

7)Connect the AC voltmeter to the speaker output connectors of the amplifier. Make sure you test the voltage at the correct connectors (+ and –).

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

9)Once you have adjusted the amplifier 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
8Ω	15.5 V	31 V
6Ω	15.5 V	28 V
4Ω	15.5 V	25 V
3Ω	14 V	not recommended
2Ω	12.5 V	not recommended

Appendix B:

J2-320.4 Specifications

General Specifications:

Recommended Fuse Value: 60A

Recommended Fuse Type: AFS, AGU or MaxiFuse™ at battery, 2 x 30A ATC fuses on amplifier chassis

Input Sections:

No. of Inputs: Two Stereo Pairs

Low-Level Inputs: Single-ended with RCA jack inputs

Low-Level Input Range: 200mV - 4V RMS

High-Level Inputs: Single-ended with molded connector

High-Level Input Range: 2V - 10V RMS

Amplifier Section:

Amplifier Topology: Class B with complementary bi-polar output stage

Power Supply: PWM switching type, unregulated

Rated Power with less than 1% THD (14.4V supply): Stereo, all channels driven:

60W RMS x 4 @ 4 ohms, 80W RMS x 4 @ 2 ohms Bridged, all channels driven:

120W RMS x 2 @ 8 ohms, 160W RMS x 2 @ 4 ohms Frequency Response: 10 Hz - 25 kHz +/- 0.5 dB

Crossover Sections:

Filter Type: 12dB/octave Butterworth

with continuously variable low-pass cutoff frequency selection from 40-150 Hz and high-pass cutoff frequency selection from 60Hz - 1.2 kHz.

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

Preamp Output:

2-Channel, pass-through with unity gain, RCA-type jacks.

Dimensions (LxWxH):

15.40" x 9.60" x 2.15" (391 mm x 244 mm x 55 mm)

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

12 JL Audio 13