JL Audio 450/4V2 User Manual

Page 5

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8 | JL Audio - 450/4

v2

Owner’s Manual

9

2)

iFilter Mode/Slopew$POUSPM5IJTTXJUDI
allows you to defeat the CH 1&2 filter or select
from two filter slopes.

iOffw%FGFBUTUIFGJMUFSGPS$)DPNQMFUFMZ 
allowing the full range of frequencies present
at the inputs to feed that pair of channels.
5IJTJTVTFGVMGPSTZTUFNTVUJMJ[JOHPVUCPBSE
crossovers or requiring full-range reproduction
from that pair of channels.

i12dBw$POGJHVSFTUIFGJMUFSGPS$)
to attenuate frequencies above or below the
selected filter frequency at a rate of 12 dB per
octave (Butterworth alignment).

i24dBw$POGJHVSFTUIFGJMUFSGPS$)
to attenuate frequencies above or below the
selected filter frequency at a rate of 24 dB per
PDUBWF -JOLXJU[3JMFZBMJHONFOU 

%FQFOEJOHPOUIFTQFBLFSTZTUFNBOE

the vehicle, different filter slopes may be
required to produce a smooth transition
between the sound of different speakers in the
system. Experiment to find the slope which
best matches the acoustic requirements of
UIFTZTUFN5IFTIBSQFSi24dBwTFUUJOHXJMM
do a better job of protecting small speakers
with limited power handling. The shallower
i12dBwPDUBWFTFUUJOHBMMPXTUIFSFBSTQFBLFST
to reproduce more low-frequency content.

3)

iFreq. RangFw$POUSPM8IFOUISPXOUP
the right, this switch multiplies the cutoff
GSFRVFODZTFMFDUFECZUIFSPUBSZiFilter Freq.
(Hz)

wDPOUSPMCZBGBDUPSPG*OUIFix1w

position, the range of the rotary control is
)[ BTNBSLFE *OUIFix10w
position, the range of the rotary control is
)[L)[ )[ 

4)

iFilter Freq. (Hz)w5IFGJMUFSGSFRVFODZ

markings surrounding this rotary control
are for reference purposes and are generally
accurate to within 1/3 octave or better. If you
would like to select the filter cutoff frequency
with a higher level of precision, consult the
charts in Appendix A (page 22) of this manual.

CH 3&4 Filter Section:

CH 3 & 4 Filter Section

CH 3

HP Filter Freq. (Hz)

(

Freq. Range

Inpu

Mode

| 4ch

x1 | x10

Low

High-Pass Filter

Off | 12dB | 24dB

50

60

75

95

130

200

500

1 & 2

and

3 & 4

Also sets

low-pass

cutoff for

CH 1 & 2

Bandpass

Filter

(if selected)

1)

iHigh-Pass Filterw$POUSPM5IJTTXJUDIBMMPXT
you to defeat the CH 3&4 filter or select from
two different filter slopes.

iOffw%FGFBUTUIFGJMUFSGPS$)DPNQMFUFMZ 
allowing the full range of frequencies present
at the inputs to feed that pair of channels.
5IJTJTVTFGVMGPSTZTUFNTVUJMJ[JOHPVUCPBSE
crossovers or requiring full-range reproduction
from these channels.

i12dBw$POGJHVSFTUIFIJHIQBTTGJMUFSGPS$)
3&4 to attenuate frequencies below the selected
filter frequency at a rate of 12 dB per octave
(Butterworth alignment).

i24dBw$POGJHVSFTUIFIJHIQBTTGJMUFSGPS$)
3&4 to attenuate frequencies below the selected
filter frequency at a rate of 24 dB per octave
-JOLXJU[3JMFZBMJHONFOU 

%FQFOEJOHPOUIFTQFBLFSTZTUFNBOEUIF

vehicle, different filter slopes may be required to
produce a smooth transition between the speakers
in the system. Experiment to find the slope
which best matches the acoustic requirements
PGZPVSTZTUFN5IFTIBSQFSi24dBwTFUUJOH
will do a better job of protecting small speakers
with limited power handling. The shallower
i12dBwPDUBWFTFUUJOHBMMPXTUIFSFBSTQFBLFSTUP
reproduce more low-frequency content.

2)

iFreq. Rangew$POUSPM8IFOUISPXOUPUIF

right, this switch multiplies the cutoff frequency
TFMFDUFECZUIFSPUBSZiFilter Freq. (Hz)w
DPOUSPMCZBGBDUPSPG*OUIFix1wQPTJUJPO 
UIFSBOHFPGUIFSPUBSZDPOUSPMJT)[ BT
NBSLFE *OUIFix10wQPTJUJPO UIFSBOHFPGUIF
SPUBSZDPOUSPMJT)[L)[ )[ 

I M P O RTA N T

!

The output of the amplifier will decrease for
a given input voltage when the “Input
Range” switch is placed in the “High”
position. Conversely, the output will be
higher with the switch in the “Low” position.
While this may sound counter-intuitive, it is
correct as described.

3) Input Sensitivity Adjustment: Located next

UPUIFiInput VoltagewTXJUDIJOFBDIJOQVU
TFDUJPOJTBSPUBSZDPOUSPMMBCFMFEiInput
Sens.

w0ODFUIFBQQSPQSJBUFiInput Voltagew

range has been selected, this control can be
used to match the source unit’s output voltage
to the input stage of each pair of amplifier
channels 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 each pair
of amplifier channels for maximum clean
output, please refer to Appendix B (page 22)
in this manual. After using this procedure,
you can then adjust the relative level of each
channel pair by adjusting the input sensitivity
downward on either or both channel pairs, if
they require attenuation to achieve the desired
TZTUFNCBMBODF%POPUJODSFBTFUIFiInput
Sens.

wTFUUJOHGPSBOZBNQMJGJFSJOUIFTZTUFN

beyond the maximum level established during
the procedure outlined in Appendix B (page
 %PJOHTPXJMMSFTVMUJOBVEJCMFEJTUPSUJPO
and possible speaker damage. Be aware that
CPUIiInput Sens.wBEKVTUNFOUTXJMMIBWFUPCF
made, regardless of how many input cables are
feeding the amplifier. These controls will allow
you to set the appropriate relative levels for CH
1&2 relative to CH 3&4 and other amplifier
channels in the system.

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.

CH 1&2 Filter Section:

CH 1 & 2 Filter Section

trol

CH

(Le

Filter Type

LP | BP | HP

Input V

Low |

Freq. Range Filter Mode | Slope

x1 | x10

Off | 12dB | 24dB

c Filter

0Hz

50

60

75

95

130

200

500

Filter Freq. (Hz)

r

e

he

nput

to

hen

ed.

1)

iFilter Typew$POUSPM-PDBUFEJOUIF

iCH 1&2 Filter Sectionw UIJTTXJUDIBMMPXT
you to configure the CH 1&2 filter into one
of three filter types:

iLPw Low-Pass): Configures the CH 1&2
filter to attenuate frequencies above
the selected filter frequency. Useful
for connection of subwoofer(s) to CH
1&2 in a bi-amplified system.

iBPw #BOEQBTT $POGJHVSFTUIFGJMUFSUP
attenuate frequencies above the selected filter
frequency and below the frequency selected
in the CH 3&4 High-Pass Filter. This creates
a true bandpass filter well-suited for driving
mid-bass or mid-range speakers in a tri-
amplified system.

iHPw High-Pass): Configures the CH 1&2
filter to attenuate frequencies below the
selected filter frequency. Useful for connection
of component speakers to CH 1&2 in a bi-
amplified system.

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