JL Audio 500/1v2 User Manual

Page 5

8 | JL Audio - 500/1

Owner’s Manual

2) Precise Frequency Selection: The filter

frequency markings on the front panel of
the amplifier are for reference purposes and
are generally accurate to within 1/3 octave
or better. If you would like to select the filter
frequency with a higher level of precision,
consult Appendix C: Chart A-1 (page 16)
of this manual. This chart gives you a more
accurate frequency for each of the forty
detented positions of the frequency selection
control. This method can be very useful if the
amplifier is mounted in a location where you
can’t see the front panel markings easily.

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.

PreamP outPut seCtion

The 500/1v2 incorporates a flexible preamp

output section, designed to make multiple
amplifier systems easy to set up.

The Preamp output can be configured in three

different “Output Modes”:

+12VDC

Ground Remote

Preamp Output Section

Infrasonic Filter

“Q”

Center Freq.

Boost (dB)

Amp LP Filter

Advanced

Bass

Control

Amplifier Input Section

Subwoofer Output

MONO OUTPUT ONLY

Left Output

Right Output

Left Ch.

Right Ch.

Filter Freq. (Hz)

Infrasonic Freq. (Hz)

Remote Bass Port

Full Range | Amp Filter | Out Filter

Output Mode

Filter Slope

Mode

Mode | Slope

Input Voltage

Input Sens. Signal Sensing

12dB | 24dB

Filter Mode

LP | HP

Bass EQ

Off | On

Off | 12dB | 24dB

Low | High

Off | On

100

200

100

200

0.5

0.7

1.1

1.6

2.7

4.3 20

+10

+13

+15

500/1

Monoblock Subwoofer Amplifier

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.

3) Input Sensitivity Adjustment: Located

next to the “Input Voltage” switch, in the
“Amplifier Input Section”, is a rotary control
labeled “Input Sens.”. Once the appropriate
“Input Voltage” range has been selected, this
rotary control can be used to match the source
unit’s output voltage to the input stage of the
amplifier for maximum clean output. Rotating
the control clockwise will result in higher
sensitivity (louder for a given input voltage).
Rotating the control counter-clockwise will
result in lower sensitivity (quieter for a given
input voltage). To properly set the amplifier
for maximum clean output, please refer to
Appendix A (page 14) in this manual. After
using this procedure, you can then adjust
the level of the amplifier by adjusting the
input sensitivity downward, if the amplifier
requires attenuation to achieve the desired
system balance. Do not increase the “Input

Sens.” setting for any amplifier in the system
beyond the maximum level established during
the procedure outlined in Appendix A (page
14). Doing so will result in audible distortion
and possible speaker damage.

CrossoVer Controls

Crossovers are groups of individual electronic

filters which allow only certain frequency
ranges to pass through them by attenuating
frequencies outside the selected range. These
filters allow the user to specify what frequency
range will be sent out of each channel section
of the amplifier. This, in turn, allows each
speaker system to only reproduce a range of
frequencies it is well-suited for, resulting in
reduced distortion and improved fidelity.

amPliFier low-Pass Filter

The 500/1v2 employs a sophisticated, state-

variable, low-pass active filter for its internal
channel. This feature is designed to attenuate
frequencies above its filter frequency, so that the
system’s subwoofers do not reproduce any audible
midrange content.

+12VDC

Ground Remote

Preamp Output Section

Infrasonic Filter

“Q”

Center Freq.

Boost (dB)

Amp LP Filter

Advanced

Bass

Control

Amplifier Input Section

Subwoofer Output

MONO OUTPUT ONLY

Left Output

Right Output

Left Ch.

Right Ch.

Filter Freq. (Hz)

Infrasonic Freq. (Hz)

Remote Bass Port

Full Range | Amp Filter | Out Filter

Output Mode

Filter Slope

Mode

Mode | Slope

Input Voltage

Input Sens. Signal Sensing

12dB | 24dB

Filter Mode

LP | HP

Bass EQ

Off | On

Off | 12dB | 24dB

Low | High

Off | On

100

200

100

200

0.5

0.7

1.1

1.6

2.7

4.3 20

+10

+13

+15

500/1

Monoblock Subwoofer Amplifier

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

500/1v2 is fully variable between 40 Hz and
200 Hz via the “Filter Freq.” control knob
and features the ability to select between a
moderate “12dB” per octave or a steep “24dB”
per octave slope via the “Mode/Slope” switch.
Depending on the subwoofer system and the
vehicle, different slopes may be required to
produce a smooth transition to the mid-bass
speakers in the system. Experiment to find
the slope which best matches the acoustic
requirements of your system.

Tuning Hint

A trunk mounted sub whose

output has to "fight" through a rear deck or a
back seat often benefits from the 12 dB/octave
slope which lets more upper bass content
pass through. A sub that fires directly into
the listening environment is more likely
to benefit from a 24 dB/octave slope.

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.