Owner's Manual
Table Of Contents
BASS
BOOST
CONTROLS
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Pre-Outs Amplifier Status
Channell
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Discrete
1&21
Sum
Remote
Bass
Port
1)
"CH
3&4 Bass Boost": Found in the
"Channel
3 & 4 Controls" section, this switch allows the
user to activate a 6
dB
boost centered at 48 Hz
for channels 3 &
4.
When
the
"CH
3&4 Bass
Boost"
is
activated, the inputs to
"CH
3 (Left)"
and
"CH
4 (Right)" are
summed
to create a
mono
signal. The "Filter Mode" switch in the
"Channel
3 & 4" section must be in the "LP"
position for the bass boost to be functional.
2) "Remote Bass
Port":
This
port
allows you
to connect an optional remote boost knob
(sold separately
as
JL
Audio Model RBC-l)
that can be mounted near the head unit. With
the RBC-l connected, the boost
is
no longer
limited to 0 or +6 dB, allowing a variable
range
of
0 to +
12
dB
of
boost to be selected.
PRE-OUTS
The M4300 incorporates a pass-through
preamp output section, so that additional
amplifiers can be easily added to the system. This
pass-through pre-amp output can be configured
two different ways using the switch labeled
"Pre-Outs
Input From".
1)
"1&2": The preamp output delivers the same
signal that
is
connected to the
CH
1&2
Inputs.
This mode is useful for feeding a subwoofer
amplifier when the M4300
is
being used to
drive front and rear speaker systems. In this
mode, the preamp output signal will depend
only on the input signal level
of
CH
1&2,
allowing Channels 3&4 to be faded without
affecting the subwoofer level.
If
CH
1&2
is
faded in this mode, the signal level
of
the
preamp output will change accordingly.
B
2) "Sum": When the M4300
is
being used to drive
front and rear speaker systems, this preamp
output mode will deliver a summed front/rear
stereo signal to a subwoofer amplifier, while
permitting fading
of
the front and rear speaker
systems from the source unit. This method
prevents a loss
of
signal to the subwoofer
amplifier when the system
is
faded to the front
or
the rear
by
the head unit.
Note: Any signal delay between the front and rear
channels can result in a cancellation
of
signals
within certain frequency ranges when using the
"Sum" position.
If
you experience a loss
of
bass
output in the "Sum" position, compared to the
"1&2" position, you are likely dealing with a
delayed signal in either the front or rear outputs
of
the source unit. Ifthe front to rear delay
is
desirable for other reasons or if
it
cannot be
defeated
at
the source unit,
we
recommend that
you use
the"
1&2" position.
Note: In either mode, the preamp output signal
is
not affected by the
"CH
3&4 Bass Boost"
processing selected for the amplifier
or
by any
crossover filter selected (if the input signal
is
full-
range, the preamp output will be full-range).
Note: The signal level
of
the
"Preamp
Output"
is
line-level (low voltage), regardless
of
the position
selected in the M4300's
"Input
Voltage" switch.
An additional amplifier connected to these
preamp outputs should have its input voltage
switch set to the "Low" position.
.JL
AUDIO
M4300