JL Audio 500/1v2 owner manual Amplifier Low-Pass Filter, Input Sensitivity Adjustment Located

Page 5

 

Amplifier Low-Pass Filter

3) Input Sensitivity Adjustment: Located

The 500/1v2 employs a sophisticated, state-

next to the “Input Voltage” switch, in the

variable, low-pass active filter for its internal

Amplifier Input Section”, is a rotary control

channel. This feature is designed to attenuate

labeled “Input Sens.”. Once the appropriate

frequencies above its filter frequency, so that the

Input Voltage” range has been selected, this

system’s subwoofers do not reproduce any audible

rotary control can be used to match the source

midrange content.

 

unit’s output voltage to the input stage of the

 

 

 

 

amplifier for maximum clean output. Rotating

(dB)

Amp LP Filter

A

the control clockwise will result in higher

0

Mode Slope

Input V

+13

sensitivity (louder for a given input voltage).

+15 Off 12dB 24dB

Low

Rotating the control counter-clockwise will

 

 

65

 

result in lower sensitivity (quieter for a given

nced

55

80

 

45

100

 

input voltage). To properly set the amplifier

 

 

rol

40

200

 

for maximum clean output, please refer to

 

Filter Freq. (Hz)

Left

 

Preamp Output Section

 

 

2) Precise Frequency Selection: The filter

The 500/1v2 incorporates a flexible preamp

frequency markings on the front panel of

output section, designed to make multiple

the amplifier are for reference purposes and

amplifier systems easy to set up.

 

are generally accurate to within 1/3 octave

The Preamp output can be configured in three

or better. If you would like to select the filter

different “Output Modes”:

 

 

frequency with a higher level of precision,

 

 

 

 

consult Appendix C: Chart A-1 (page 16)

 

 

 

 

of this manual. This chart gives you a more

Preamp Output Section

 

accurate frequency for each of the forty

Output Mode

Filter Slope

 

detented positions of the frequency selection

Full Range Amp Filter Out Filter

12dB 24dB

 

control. This method can be very useful if the

 

 

65

 

Filter Mode

amplifier is mounted in a location where you

 

55

80

 

45

100

 

can’t see the front panel markings easily.

 

40

200

LP HP

Left Output Right Output

Filter Freq. (Hz)

Appendix A (page 14) in this manual. After

 

 

 

 

 

 

using this procedure, you can then adjust

 

 

 

the level of the amplifier by adjusting the

1) Filter Operation: The low-pass filter in the

input sensitivity downward, if the amplifier

500/1v2 is fully variable between 40 Hz and

requires attenuation to achieve the desired

200 Hz via the “Filter Freq.” control knob

system balance. Do not increase the “Input

and features the ability to select between a

Sens.” setting for any amplifier in the system

moderate “12dB” per octave or a steep “24dB

beyond the maximum level established during

per octave slope via the “Mode/Slope” switch.

the procedure outlined in Appendix A (page

Depending on the subwoofer system and the

14). Doing so will result in audible distortion

vehicle, different slopes may be required to

and possible speaker damage.

produce a smooth transition to the mid-bass

 

speakers in the system. Experiment to find

CROSSOVER CONTROLS

the slope which best matches the acoustic

Crossovers are groups of individual electronic

requirements of your system.

filters which allow only certain frequency

 

 

 

ranges to pass through them by attenuating

Tuning Hint: A trunk mounted sub whose

frequencies outside the selected range. These

output has to "fight" through a rear deck or a

filters allow the user to specify what frequency

back seat often benefits from the 12 dB/octave

range will be sent out of each channel section

slope which lets more upper bass content

of the amplifier. This, in turn, allows each

pass through. A sub that fires directly into

speaker system to only reproduce a range of

the listening environment is more likely

frequencies it is well-suited for, resulting in

to benefit from a 24 dB/octave slope.

reduced distortion and improved fidelity.

 

 

 

 

The above hint is not “set-in-stone”…

 

You should always listen to the system carefully

 

to determine the best choice as vehicle acoustics

 

and other factors play a big role in choosing the

 

most appropriate filter slope.

3)Defeating the Amplifier Filter: The Low- Pass filter can also be defeated completely, by switching the “Mode/Slope” switch to the “Off” position. This is useful if you are using an external active crossover in the system. Keep in mind that turning the internal crossover off also defeats the “Advanced Bass Control” section processing (see page 9 for details). With the internal crossover turned off, the 500/1v2’s upper frequency response limit is

250 Hz, due to its bass-specific Class D design.

1)“Full-Range”:This is a pass-through mode for the preamp output, delivering the same signal that is being fed to the “Amplifier Input Section” (If the input signal is full-range,the preamp output will be full-range). This signal is not affected by the “Advanced Bass Control” processing selected for the amplifier.

2)“Amp Filter”: The preamp output delivers the same signal that is feeding the 500/1v2’s amplifier section, including all the processing induced by the “Amp LP Filter” and “Advanced Bass Control” sections. This is primarily used for running additional 500/1v2’s in a “Slave” configuration from the “Master” amplifier. For detailed information on

“Master/Slave” configurations, see Appendix D (page 18). If the “Output Mode” switch is in the “Amp Filter” position and the “Amp LP Filter” switch is in the “Off” position, there will be no output from the preamp output jacks. The independent output filter controls

(“Filter Slope”, “Filter Freq” and “Filter Mode”) are inactive in “Amp Filter” mode.

8 JL Audio - 500/1v2 Owner’s Manual

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Contents Monoblock subwoofer amplifier Planning Your Installation Installation ApplicationsSafety Considerations Protect Your HearingProduct Description Power ConnectionsMany vehicles employ small 10 AWG Fuse RequirementsAmplifier Input Section Turn-On OptionsAmplifier Low-Pass Filter Input Sensitivity Adjustment LocatedPreamp Output Section Precise Frequency Selection The filterSubwoofer Output ADVANCED Bass Control SectionThermal Red lights to indicate that Status Indicator Lights Protection CircuitryNine-Step Procedure Appendix a Input Sensitivity Level SettingAppendix B 500/1v2 Specifications General Specifications Dimensions LxWxHFull-clockwise Appendix C  Precise Frequency Selection ChartActual Detent Panel Detent PanelMaster/Slave configuration following the same Appendix D Master/Slave ConfigurationsMaster Slave aMy amplifier turns on, but there is no output My amplifier doesn’t turn on500/1v2 INSTALLATION NOTESIf you need service on your JL Audio product Limited Warranty Amplifiers USAJL Audio, Inc International Warranties