8
| JL Audio - 450/4
v2
Owner’s Manual
9
2)
i
Filter Mode/Slope
w$POUSPM5IJTTXJUDI
allows you to defeat the CH 1&2 filter or select
from two filter slopes.
i
Off
w%FGFBUTUIFGJMUFSGPS$)DPNQMFUFMZ
allowing the full range of frequencies present
at the inputs to feed that pair of channels.
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crossovers or requiring full-range reproduction
from that pair of channels.
i
12dB
w$POGJHVSFTUIFGJMUFSGPS$)
to attenuate frequencies above or below the
selected filter frequency at a rate of 12 dB per
octave (Butterworth alignment).
i
24dB
w$POGJHVSFTUIFGJMUFSGPS$)
to attenuate frequencies above or below the
selected filter frequency at a rate of 24 dB per
PDUBWF -JOLXJU[3JMFZBMJHONFOU
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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
UIFTZTUFN5IFTIBSQFSi
24dB
wTFUUJOHXJMM
do a better job of protecting small speakers
with limited power handling. The shallower
i
12dB
wPDUBWFTFUUJOHBMMPXTUIFSFBSTQFBLFST
to reproduce more low-frequency content.
3)
i
Freq. Rang
Fw$POUSPM8IFOUISPXOUP
the right, this switch multiplies the cutoff
GSFRVFODZTFMFDUFECZUIFSPUBSZi
Filter Freq.
(Hz)
wDPOUSPMCZBGBDUPSPG*OUIFi
x1
w
position, the range of the rotary control is
)[ BTNBSLFE*OUIFi
x10
w
position, the range of the rotary control is
)[L)[ )[
4)
i
Filter Freq. (Hz)
w5IFGJMUFSGSFRVFODZ
markings surrounding this rotary control
are for reference purposes and are generally
accurate to within 1/3 octave or better. If you
would like to select the filter cutoff frequency
with a higher level of precision, consult the
charts in Appendix A (page 22) of this manual.
CH 3&4 Filter Section:
CH 3 & 4 Filter Section
CH 3
HP Filter Freq. (Hz)
(
Freq. Range
Inpu
Mode
| 4ch
x1 | x10
Low
High-Pass Filter
Off | 12dB | 24dB
50
60
75
95
130
200
500
1 & 2
and
3 & 4
Also sets
low-pass
cutoff for
CH 1 & 2
Bandpass
Filter
(if selected)
1)
i
High-Pass Filter
w$POUSPM5IJTTXJUDIBMMPXT
you to defeat the CH 3&4 filter or select from
two different filter slopes.
i
Off
w%FGFBUTUIFGJMUFSGPS$)DPNQMFUFMZ
allowing the full range of frequencies present
at the inputs to feed that pair of channels.
5IJTJTVTFGVMGPSTZTUFNTVUJMJ[JOHPVUCPBSE
crossovers or requiring full-range reproduction
from these channels.
i
12dB
w$POGJHVSFTUIFIJHIQBTTGJMUFSGPS$)
3&4 to attenuate frequencies below the selected
filter frequency at a rate of 12 dB per octave
(Butterworth alignment).
i
24dB
w$POGJHVSFTUIFIJHIQBTTGJMUFSGPS$)
3&4 to attenuate frequencies below the selected
filter frequency at a rate of 24 dB per octave
-JOLXJU[3JMFZBMJHONFOU
%FQFOEJOHPOUIFTQFBLFSTZTUFNBOEUIF
vehicle, different filter slopes may be required to
produce a smooth transition between the speakers
in the system. Experiment to find the slope
which best matches the acoustic requirements
PGZPVSTZTUFN5IFTIBSQFSi
24dB
wTFUUJOH
will do a better job of protecting small speakers
with limited power handling. The shallower
i
12dB
wPDUBWFTFUUJOHBMMPXTUIFSFBSTQFBLFSTUP
reproduce more low-frequency content.
2)
i
Freq. Range
w$POUSPM8IFOUISPXOUPUIF
right, this switch multiplies the cutoff frequency
TFMFDUFECZUIFSPUBSZi
Filter Freq. (Hz)
w
DPOUSPMCZBGBDUPSPG*OUIFi
x1
wQPTJUJPO
UIFSBOHFPGUIFSPUBSZDPOUSPMJT)[ BT
NBSLFE*OUIFi
x10
wQPTJUJPOUIFSBOHFPGUIF
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
UPUIFi
Input Voltage
wTXJUDIJOFBDIJOQVU
TFDUJPOJTBSPUBSZDPOUSPMMBCFMFEi
Input
Sens.
w0ODFUIFBQQSPQSJBUFi
Input Voltage
w
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%POPUJODSFBTFUIFi
Input
Sens.
wTFUUJOHGPSBOZBNQMJGJFSJOUIFTZTUFN
beyond the maximum level established during
the procedure outlined in Appendix B (page
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and possible speaker damage. Be aware that
CPUIi
Input 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)
i
Filter Type
w$POUSPM-PDBUFEJOUIF
i
CH 1&2 Filter Section
wUIJTTXJUDIBMMPXT
you to configure the CH 1&2 filter into one
of three filter types:
i
LP
w
Low-Pass
): Configures the CH 1&2
filter to attenuate frequencies above
the selected filter frequency. Useful
for connection of subwoofer(s) to CH
1&2 in a bi-amplified system.
i
BP
w #BOEQBTT$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.
i
HP
w
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.
