JL Audio HD600/4 Appendix B Precise Frequency Selection Chart, Appendix C, Necessary Equipment

Appendix B: 

Precise Frequency Selection Chart

“Filter FREQ”

Detent Panel Actual

Number Marking Freq.

Full counter-clockwise: 53

01 . . . . . . “50” . . . . . .53 02 . . . . . . . . . . . . . . 53 03 . . . . . . . . . . . . . . 53 04 . . . . . . . . . . . . . . 53 05 . . . . . . . . . . . . . . 54 06 . . . . . . . . . . . . . . 56 07 . . . . . . . . . . . . . . 58 08 . . . . . . “60” . . . . . .60 09 . . . . . . . . . . . . . . 62 10 . . . . . . . . . . . . . . 64 11 . . . . . . . . . . . . . . 66 12 . . . . . . . . . . . . . . 68 13 . . . . . . . . . . . . . . 71 14 . . . . . . . . . . . . . . 74 15 . . . . . . . . . . . . . . 76 16 . . . . . . “80” . . . . . .80 17 . . . . . . . . . . . . . . 83 18 . . . . . . . . . . . . . . 87 19 . . . . . . . . . . . . . . 91 20 . . . . . . . . . . . . . . .94 21 . . . . . . . . . . . . . . 99 22 . . . . . . . . . . . . . . 104 23 . . . . . . . . . . . . . . 109 24 . . . . “12 o’clock” . . . 115 25 . . . . . . . . . . . . . . 121 26 . . . . . . . . . . . . . . 128 27 . . . . . . . . . . . . . . 137 28 . . . . . . . . . . . . . . 147 29 . . . . . . . . . . . . . . 160 30 . . . . . . . . . . . . . . 174

Appendix C:

Input Sensitivity Level Setting JL Audio amplifiers utilizing the Regulated

Intelligent Power Supply (R.I.P.S.) allow delivery of their rated power when connected to any load impedance from 1.5 - 4Ω per channel and when connected to a charging system with any voltage from 11 - 14.5V. This design is beneficial for many reasons. One of these reasons is ease of setup.

Because each JL Audio amplifier will always deliver the same amount of power within its operational range of impedances and supply voltages, the maximum, unclipped output is very predictable.

This makes setting the gain structure via the input sensitivity controls very simple. Following the directions below will allow the user to adjust the input sensitivity of the amplifier(s) 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). The CleanSweep®

Calibration Disc contains the appropriate test tones and is available for sale at http://store.jlaudio.com Do not use attenuated test tones (-10 dB, -20 dB, etc.).

The Nine-Step Procedure

(follow this procedure for each pair of channels)

1)Disconnect the Speaker Connector Plugs.

2)Turn off all processing on the source unit (bass/treble, loudness, EQ, etc.). Set fader control to center position and subwoofer level control to 3/4 of maximum (if used to drive the HD600/4). Disconnect the HD-RLC Remote Level Control temporarily (if one is being used).

3)Switch the “Input Voltage” to “Low” and turn the “Input Sens.” control on both sets of channels all the way down.

4)Set the source unit volume to 3/4 of full volume. If either set of channels is being driven by a source unit’s dedicated subwoofer output, also adjust the source unit’s subwoofer level control to 3/4 of maximum output. This will allow for reasonable gain overlap with moderate clipping at full volume.

5)Using the chart below, determine the target voltage for input sensitivity adjustment according to the nominal impedance of the speaker system connected to each set of outputs.

6)Verify that you have disconnected the Speaker

Connector Plugs before proceeding. Play a track with an appropriate sine wave (within the frequency range to be amplified by each set of channels) at 3/4 source unit volume.

7)Connect the AC voltmeter to the “Front Speaker Outputs” or “Rear Speaker Outputs” connectors of the amplifier. If the channel pair is operating in stereo, it is only necessary to measure one channel in the pair. 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 delivered for that set of channels. If excessive voltage is read on either set of channels with the control at minimum (full counterclockwise), switch the appropriate “Input Voltage” switch to “High” and re-adjust.

9)Once you have adjusted each set of channels to its maximum unclipped output level, reconnect the speaker(s). The “Input Sens.” controls can now be adjusted downward if either or both sets of channels requires attenuation to achieve the desired system balance.

31 . . . . . . . . . . . . . . 191 32 . . . . . . . . . . . . . . 211 33 . . . . . “250” . . . . . 236 34 . . . . . . . . . . . . . . 269 35 . . . . . . . . . . . . . . 309 36 . . . . . . . . . . . . . . 369 37 . . . . . . . . . . . . . . 443 38 . . . . . “500” . . . . . 484 39 . . . . . . . . . . . . . . 525

Full-clockwise: 528

Do not increase any “Input Sens.” setting 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, source unit tone controls or EQ circuits. EQ cuts will not require re-adjustment.

Nom.	Front channels		Rear Channels
Impedance	Stereo	Bridged	Stereo	Bridged
8Ω	24.5 V	49.0 V	24.5 V	49.0 V
6Ω	24.5 V	42.4 V	24.5 V	42.4 V
4Ω	24.5 V	34.6 V	24.5 V	34.6 V
3Ω	21.2 V	30.0 V	21.2 V	30.0 V
2Ω	17.3 V	not recommended	17.3 V	not recommended
1.5Ω	15.0 V	not recommended	15.0 V	not recommended

18 JL Audio - HD600/4 Owner’s Manual 19