Speaker Outputs - JL Audio Slash 450/4 User Manual

"Filter Mode/Slope" switch on "12dB" and rotate
the frequency selection knob fully clockwise to the
"500 Hz" position.This will activate the bass
controls without significantly affecting the crossover
point selected by the external active crossover.

SPEAKER OUTPUTS

The 450/4 employs JL Audio's exclusive
Regulated, Intelligent Power Supply (R.I.P.S.) design.
The operation of the R.I.P.S. system is independent
for each pair of channels.This sophisticated power
supply allows the amplifier to produce its optimum
power (150 watts x 2 for channels 1&2 and
75 watts x 2 for channels 3&4) over a wide range
of speaker impedances.
Unlike conventional amplifiers that require a
specific impedance to produce optimum power, the
R.I.P.S.-equipped 450/4 gives you the freedom to
use a variety of speaker configurations that achieve
final nominal impedances between 1.5 – 4Ω per
channel in stereo (without sacrificing power output
or sound quality). When bridged, each channel pair
will optimize output between 3 – 8Ω.
The operation of the R.I.P.S. circuitry is entirely
automatic and adjusts itself every time the amplifier
is turned on according to the lowest impedance
present at the speaker load.There are no user
controls to configure.The system operates through
multiple stages of impedance optimization, choosing
the stage most appropriate to the actual impedance
of the speakers you connect to it.
!
I M P O RTA N T
If you connect a load higher than 4Ω nominal
per channel in stereo mode (or 8Ω in bridged
mode), power will drop by half with every
doubling of impedance above 4Ω stereo / 8Ω
mono. If you connect a load lower than 1.5Ω
nominal per channel in stereo mode (or 3Ω in
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bridged mode, the amplifier protection circuitry
activates a "safe" mode which reduces amplifier
power to protect the circuitry from failure (the
yellow "Low Ω" LED lights to indicate that this
has happened). See page 11 for details.
!
I M P O RTA N T
Speaker loads below 1.5Ω nominal per channel
in stereo or 3Ω nominal in bridged mode are not
recommended and may cause the amplifier output
to distort excessively.
BRIDGING CONSIDERATIONS
Bridging is the practice of combining the output
of two amplifier channels to drive a single load.
When bridged, each channel produces signals of
equal magnitude, but opposite polarity.The
combined output of the two channels provides
twice the output voltage available from a single
channel.The 450/4 has been designed for bridging
of its channel pairs without the need for input
inversion adaptors.
To bridge a pair of channels, use the "Left +" and
"Right –" speaker connectors only (the "Left –"
and "Right +" remain unused).Then connect a
mono signal to both left and right RCA inputs for
that channel pair.This requires an RCA "Y-adaptor"
(not included.) When bridged, each channel pair will
deliver optimum power into a 3-8Ω load. Operating
bridged channel pairs into a load lower than 3Ω is
not recommended.
Because a bridged pair of channels requires that
both channels receive input, you need to connect
both left and right RCA inputs to the bridged
channel pair's inputs. Connection of only one RCA
input will result in reduced power output, increased
distortion and can cause the amplifier to overheat.
Do not do this! Instead, use a "Y-adaptor" to split
the mono signal into both left and right RCA inputs.
JL AUDIO 450/4
Why a mono signal? If you are bridging a pair of
channels and use a stereo input, the only
information that will reach the amplifier stage is the
common-phase portion of the signal.This may be
useful for passively deriving a center-channel signal,
but is not going to give you a defined left or right
channel. If you are looking to reproduce a single
channel's signal, you must split the mono signal with
a "Y-adaptor" and connect it to both left and right
RCA inputs for the bridged channel pair.
STATUS INDICATOR LIGHTS /
PROTECTION CIRCUITRY
There are three status indicator lights on the top
of the amplifier. These are as follows:
1) "Power" (Green): lights to indicate that the
amplifier is turned on and operating normally.
2) "Thermal" (Red): lights to indicate that the
amplifier has exceeded its safe operating
temperature, putting the amplifier into a self-
protection mode, which reduces the power output
of the amplifier. The red light will shut off and the
amplifier will return to normal, full-power operating
mode if the heat sink temperature drops back to a
safe level.
3) "Low Ω" (Amber): lights to indicate that the
impedance of the speaker load connected to the
amplifier is lower than the optimum load impedance
range for the amplifier.When this light is on, a
protection circuit engages and reduces the power
output of CH 1&2 or CH 3&4, depending on which
channel is experiencing the problem.The amber
indicator will also light when a short-circuit is
detected in the speaker wiring (this can be a short
between the positive and negative speaker wires or
between either speaker wire and the vehicle
chassis).This can be used to diagnose a short-circuit
by only connecting one of the amplifier sections at a
time (CH 1&2 and CH 3&4).
The amber LED will light when you connect the
section that is experiencing the problem and turn
the volume up.
JL AUDIO 450/4
There is only one condition that will shut
down an undamaged 450/4 completely...
If battery voltage drops below 10 volts, the entire
amplifier will shut itself off.The green "Power"
indicator on the top of the amplifier will turn off
when this occurs.The amplifier will turn back on
when voltage climbs back above 10 volts.This may
happen in a rapid cycle when bass-heavy program
material causes a weak charging system to dip
below 10 volts momentarily. If this is happening in
your system, have your charging system inspected to
make sure it is working properly. A 0.5 or 1.0 Farad
rapid-discharge capacitor connected in parallel to
the amplifier power connections will minimize these
short duration voltage dips in most systems that are
having this problem.
For information on troubleshooting this
amplifier, refer to Appendix C (page 22).
SERVICING YOUR JL AUDIO AMPLIFIER
If your amplifier fails or malfunctions, please
return it to your authorized JL Audio dealer so
that it may be sent in to JL Audio for service.
There are no user serviceable parts or fuses
inside the amplifier.The unique nature of the
circuitry in the JL Audio amplifiers requires
specifically trained service personnel. Do not
attempt to service the amplifier yourself or
through unauthorized repair facilities.This will not
only void the warranty, but may result in the
creation of more problems within the amplifier.
If you have any questions about the installation or
setup of the amplifier not covered in
this manual, please contact your dealer or the
JL AUDIO Technical Department for assistance:
(954) 443-1100
9:00 AM – 5:30 PM Eastern Time,
Monday – Friday
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