JL Audio 1000/1v2 User Manual

Page 5

8 | JL Audio - 1000/1

Owner’s Manual

PreamP outPut seCtion

The 1000/1v2 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.

Output Polarity

12dB | 24dB

Filter Mode

LP | HP

Bass EQ

Off | On

Off | 12dB | 24dB

Low | High

Normal|Reversed

Off | On

120

200

100

200

0.5

0.7

1.1

1.6

2.7

4.3 20

+10

+13

+15

1000/1

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 1000/1v2’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
1000/1v2’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) “Out Filter”: The preamp output is

filtered by a fully variable, active filter
incorporated into the output section
and is not affected by the bass control
processing selected for the amplifier. In
“Out Filter” mode, the user can select:

a) High-pass (“HP”) or low-pass (“LP”)

filtering by way of the “Filter Mode” switch.

b) 12 dB/octave or 24 dB/ octave filter slope by

way of the “Filter Slope” switch.

c) A filter cutoff frequency between 40 - 200

Hz for the preamp output signal by way of
the “Filter Control” switch.

This is completely independent of the

amplifier’s internal filter and allows the user to
match, stagger or overlap the subwoofer low-pass
filter frequency of the amplifier crossover with
the output filter’s frequency for precise control
and optimized midbass performance.

If you would like to select the filter frequency

with a higher level of precision, consult
Appendix C: Chart A-2 (page 16) of this manual.

CAUTION

The signal level of the “Preamp Output” is

always low level regardless of the voltage

applied to this amplifier’s inputs and the

setting chosen on this amplifier’s “Input

Range” switch. All “Slave” amplifiers should

have their switches set to “Low”. See Appendix

D (page 18) for details.

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 1000/1v2 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

1000/1v2 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.

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 1000/1v2’s upper frequency response
limit is 250 Hz, due to its bass-specific
Class D design.