Bass Boost Controls; Speaker Outputs; Bridging Considerations - JL Audio E4300M Owner's Manual

BASS BOOST CONTROLS

1) CH 3&4 Bass Boost: 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, JL Audio Model RBC-1) that can be
mounted in the front of the vessel. With the
RBC-1 connected, the boost is no longer limited to
0 or +6 dB, allowing a range of 0 - 12 dB of boost
to be selected.
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PRE-OUTS
The e4300M's "Pre-Outs" connectors output
unprocessed (pass-through) left and right channel
preamp level signals, permitting connection of
additional amplifiers in a system.This pass-through
pre-amp output can be configured two different ways
using the switch labeled "Pre-Outs Input From".
1) "1&2": In this mode, the preamp output
delivers the same signal that is connected to the
e4300M's "CH 1 (Left)" and "CH 2 (Right)"
Inputs. This mode is useful for feeding a
subwoofer amplifier when the e4300M is being
used to drive front and rear speaker systems.This
preamp output mode will track the signal level of
channels 1&2, allowing fading of the rear channels
without affecting the subwoofer level.
2) "Sum": This mode sends a sum of the channels
1 & 3 input signals to the left pre-out connector and
a sum of the channels 2 & 4 input signals to the right
pre-out connector.This signal is not affected by the
"CH 3&4 Bass Boost" processing selected for the
amplifier or by any crossover filter selected.When the
e4300M is being used to drive front and rear speaker
systems, this preamp output mode will deliver a
summed front/rear signal to the subwoofer amplifier,
while permitting fading of the front and rear speaker
systems from the source unit.
When using either the line level inputs (RCA
input connections) or the "High Level Inputs"
(four-pin connector), the output signals are identical
to the input signals. If the "High Level Inputs" are
used, the signal present at the "Pre-Outs" can still
be sent to another JL Audio amplifier. In either case,
the "Pre-Outs" signals are not affected by any
settings in the "Amplifier Controls" or "CH 3&4
Bass Boost" sections.
JL AUDIO e4300M

SPEAKER OUTPUTS

The e4300M's speaker outputs are designed to
accept 8 AWG - 16 AWG wire.
Each pair of the e4300M's channels are
designed to deliver power into speaker loads equal
to or greater that 2 when using a "stereo"
configuration and speaker loads equal to or greater
than 4 when using a "bridged" configuration.
!
I M P O RTA N T
Speaker loads below 2 nominal per channel
are not recommended and may cause the amplifier
to initiate a protection mode and shut itself off.

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 e4300M 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).When bridged, each
channel will deliver optimum power into a 4 load.
JL AUDIO e4300M
! I M P O RTA NT
When a pair of channels are bridged, they will
deliver 150W x 1 into a 4 load or 90W x 1 into
an 8 load. Operating a pair of bridged channels
into a load lower than 4 is not recommended.
Because a bridged pair of channels requires that
both channels receive input, you need to connect
both left and right inputs to the source unit.
Connection of only one input will result in reduced
power output, increased distortion and can cause
the amplifier to overheat. Do not do this!
When a pair of the e4300M's channels are
operating in bridged mode, the output will be in
mono (only one channel).This mono channel can
contain right channel only information, left channel
only information or the sum of the information
from both the right and left channels. In order to
achieve one of these options, configure the inputs
to that pair of channels in one of these two ways:
1) Left Channel Only or Right Channel Only
Information: If you wish to send a Left-only or
Right-only signal to a pair of the e4300M's channels,
use a "Y-Adaptor" to split the single channel signal
into both left and right RCA inputs (or parallel-
connect both positive and both negative high-level
input connections to a single channel source signal).
This option is useful when using a pair of the
e4300M's channels to drive left channel speakers
only and the other pair of the e4300M's channels to
drive right channel speakers only.
!
I M P O RTA NT
When parallel-connecting both positive and both
negative high-level input connections as described
above, make sure to connect negative (–) wires to
negative (–) wires and positive (+) wires to positive
(+) wires.
2) Left + Right Channel Information: When
bridged and fed by a stereo input, a pair of the
e4300M's channels will automatically combine the
left and right channels into a summed mono (left +
right) channel.This option is useful when using a pair
of the e4300M's channels to drive a subwoofer
system or a summed mono center channel.
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