AMPLIFIER CONTROLS
Input Sensitivity
These controls, labeled
“Input Sens.”
,can be
used to match the source unit's output voltage(s)
to each input stage of the e4300M for maximum
clean output. Rotating an
“Input Sens.”
control
clockwise will result in higher sensitivity (louder for
a given input voltage). Rotating an
“Input Sens.”
control counter-clockwise will result in lower
sensitivity (quieter for a given input voltage.)
To properly set the amplifier for maximum clean
output, please refer to Appendix A (page 14) in this
manual. After using this procedure, you can then
adjust any or all
“Input Sens.”
levels
downward
if this
is required to achieve the desired system balance.
Do not increase any “Input Sens.” setting for
any channel(s) of any amplifier in the system
beyond the maximum level established during the
procedure outlined in Appendix A (page 14).
Doing so will result in audible distortion and
possible speaker damage.
Filter Controls
Most speakers are not designed to reproduce
the full range of frequencies audible by the human
ear. For this reason, most speaker systems are
comprised of multiple speakers, each dedicated to
reproducing a specific frequency range. Filters are
used to select which frequency range is sent to
each section of a speaker system.The division of
frequency ranges to different speakers can be
done with passive filters (coils and/or capacitors
between the amplifier outputs and the speakers),
which are acceptable and commonly used for
filtering between mids and tweeters. Filtering
between subwoofer systems and satellite speaker
systems is best done with active filters, which cut
off frequency content at the input to the amplifier.
Active filters are more stable than passive filters
and do not introduce extraneous resistance,
which can degrade subwoofer performance.
The active filter built into each channel of the
e4300M can be used to eliminate potentially
harmful and/or undesired frequencies from making
their way through the amplifier sections to the
speaker(s).This serves to improve tonal balance and
to avoid distortion and possible speaker failure.
Correct use of these filters can substantially increase
the longevity and fidelity of your audio system.
1) “Filter Mode” Control:
The e4300M employs a
12dB per octave filter for each pair of channels (one
filter for channels 1&2 and another filter for channels
3&4). Each of these filters can be configured
independently into one of two filter types or
defeated completely by way of the three-position
“Filter Mode”
switches:
“Off”:
Defeats the filter completely, allowing the full
range of frequencies present at the inputs to feed the
amplifier.This is useful for systems utilizing outboard
crossovers or requiring full-range reproduction from
one or both of the e4300M’s channel pairs.
“LP” (Low-Pass):
Configures the filter to attenuate
frequencies above the selected filter frequency at a
rate of 12dB per octave.This is useful for connection
of subwoofer(s) to one or both of the e4300M’s
channel pairs in a bi-amplified system.
“HP” (High-Pass):
Configures the filter to attenuate
frequencies below the selected filter frequency at a
rate of 12dB per octave.This is useful for connection
of component speakers to one or both of the
e4300M’s channel pairs in a bi-amplified system.
2) “Filter Freq. (Hz)”
The filter frequency
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 chart in Appendix B (page 15).
Tuning Hint:
If you are using the e4300M to drive
a subwoofer system (
“LP”
mode), a component
satellite speaker system (
“HP”
mode) or both,
100 Hz is a good baseline
“Filter Freq. (Hz)”
setting. After properly adjusting the
“Input Sens.”
,
as outlined in Appendix A (page 14), you can fine
tune the
“Filter Freq. (Hz)”
control to achieve the
desired system frequency response.
JL AUDIO
e4300M
7
TURN-ON LEAD
The e4300M uses a conven12V remote
turn-on lead, typically controlled by the source unit's
remote turn-on output.The amplifier will turn on
when +12V is present at its
“Remote”
input and
turn off when +12V is switched off. If a source unit
does not have a dedicated remote turn-on output,
the amplifier’s turn-on lead can be connected to
+12V via a switch that derives power from an
ignition-switched circuit.
The e4300M's
“Remote”
turn-on connector is
designed to accept 18 AWG – 12 AWG wire.To
connect the remote turn-on wire to the amplifier,
first back out the set screw on the top of the
terminal block, using the supplied 2.5mm hex
wrench. Strip 1/2 inch (12mm) of wire and insert
the bare wire into the terminal block, seating it
firmly so that no bare wire is exposed. While
holding the wire in the terminal, tighten the set
screw firmly, taking care not to strip the head of the
screw and making sure that the wire is firmly
gripped by the set screw.
INPUT SECTION
The e4300M’s input section allows you to send
signal to the amplifier section through the use of
either two or four inputs and offers two distinct
input connection options.These are:
1)
Two pairs of traditional RCA type connections
designed to accept input from source units with line
level outputs. (This is the preferred input method.)
2)
An eight-pin connector designed to accept
input from amplified sources such as factory source
units or source units not equipped with line
level outputs.
If you wish to send four discrete channels into the
e4300M, simply use all four inputs (channels 1 & 2
and channels 3 & 4) and set the
“CH 3&4 Input
From”
switch to
“Discrete”
.
If you wish to feed all four channels by using only
two channels of input, set the
“CH 3&4 Input
From”
switch to
“1&2”
and use only the inputs to
channels 1 & 2.
The same input connection option does not
need to be used for each channel pair.The
“Input
Sens.”
adjustment is independent for each channel
pair and must be adjusted based on input level and
the impedance of the load on that pair of channels.
Specific
“Input Sens.”
adjustment information is
given in Appendix A (page 14).
6
JL AUDIO
e4300M
