appendIX a:
Input sensitivity level setting
Following the directions below will allow the
installer to adjust the input sensitivity of each
amplifier channel pair simply and easily in just a
few minutes using equipment which is commonly
available in installation bays.
necessary equipment
• Digital AC Voltmeter
• CD with a sine-wave test tone recorded at
0 dB reference level in the frequency range
to be amplified (50 Hz is a good choice). Do not
use attenuated test tones (-10 dB, -20 dB, etc.).
the nine-step procedure
1) Disconnect the subwoofer(s) from the
amplifier's subwoofer output connector (you
need only disconnect Pos. or Neg., not both).
2) Turn off all processing (bass/treble, loudness,
EQ, etc.) on the source unit, processors (if
used) and amplifier. Set the source unit's fader
control to center position and its subwoofer level
control to 3/4 of maximum. If connected, set the
amplifier's Remote Level Control at maximum
(full clockwise).
3) Turn the amplifier's "Input Sens." control all
the way down.
4) Set the source unit volume to 3/4 of full
volume. This will allow for reasonable gain
overlap with moderate clipping at full volume.
5) Using the charts on this page, determine the
target voltage for input sensitivity adjustment
according to the nominal impedance of the
speaker system connected to the amplifier
outputs. Make sure you reference the appropriate
chart for your specific JX monoblock model.
6) Verify that you have disconnected the speakers
before proceeding. Play a track with an
appropriate sine wave (50 Hz is recommended)
at 3/4 source unit volume.
7) Connect the AC voltmeter to the speaker output
connectors of the amplifier. Make sure you test
the voltage at the correct connectors (+ and –).
8) Increase the "Input Sens." control until the
target voltage is observed with the voltmeter.
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9) Once you have adjusted the amplifier to
its maximum low-distortion output level,
reconnect the speaker(s) and listen to the
system. The "Input Sens." controls can
now be adjusted downward if the amplifier
requires attenuation to achieve the desired
system balance.
!
I m p o r ta n t !
Do not increase any "Input Sens." setting for
any amplifier channel or channel pair in the
system beyond the maximum level established
during this procedure. Doing so will result in
audible distortion and possible speaker damage.
It will be necessary to re-adjust the
"Input Sens." for the affected channels if any
equalizer boost is activated after setting the
"Input Sens." with this procedure. This applies
to any EQ boost circuit, including source unit
tone controls or EQ circuits. EQ cuts will not
require re-adjustment.
JX250/1
nom. Impedance
target ac Voltage
4Ω
26.5 V
3Ω
25.1 V
2Ω
22.4 V
JX500/1d
nom. Impedance
target ac Voltage
4Ω
34.6 V
3Ω
35.5 V
2Ω
31.6 V
JX1000/1d
nom. Impedance
target ac Voltage
4Ω
44.7 V
3Ω
47.4 V
2Ω
44.7 V
JL Audio
appendIX b:
specifications
Input section (all models):
Low-Level Input: Single-ended with RCA jacks
Low-Level Input Range: 200mV - 4V RMS
High-Level Input: Single-ended with molded connector
High-Level Input Range: 2.0V - 10.0V RMS
signal processing (all models):
Filter Type: 12dB/octave Low-Pass with continuously
variable cutoff frequency selection from 50 - 200 Hz.
Not defeatable.
Preamp Output: 2-Ch., pass-through with RCA-type jacks
Bass Boost: Single-band with 45 Hz center frequency,
adjustable from 0 to +12dB.
Remote Level Control: Via optional, wired RBC-1 remote
control knob. Full mute to 0 dB range. (RBC-1 is sold
separately.)
JX250/1 specifications:
Amplifier Topology: Class A/B
Power Supply: Unregulated PWM switching type
Frequency Response: 10 - 150 Hz (+0/– 1 dB)
Signal to Noise Ratio:
>87 dBA referred to highest rated power, >63 dBA
referred to 1W (20 Hz - 20 kHz noise bandwidth)
Damping Factor: >160 @ 4 ohms
THD + Noise @ Rated Power: 1 %
Rated Continuous (RMS) Power @ 14.4V:
175W RMS x 1 @ 4Ω
210W RMS x 1 @ 3Ω
250W RMS x 1 @ 2Ω
Rated Continuous (RMS) Power @ 12.5V:
130W RMS x 1 @ 4Ω
170W RMS x 1 @ 3Ω
210W RMS x 1 @ 2Ω
Recommended Fuse Value (Type): 30A (MAXI or AGU)
Minimum Copper Power/Ground Wire Gauge: 8 AWG
Dimensions (LxWxH):
10.94" x 7.68" x 2.09" (278 mm x 195 mm x 53 mm)
Net Weight: 6.0 lbs. (2.72 kg)
JX250/1 • JX500/1D • JX1000/1D
JX500/1d specifications:
Amplifier Topology: Class D
Power Supply: Unregulated PWM switching type
Frequency Response: 10 - 150 Hz (+0/– 1 dB)
Signal to Noise Ratio:
>62 dBA referred to highest rated power, >35 dBA
referred to 1W (20 Hz - 20 kHz noise bandwidth)
Damping Factor: >1000 @ 4 ohms
THD + Noise @ Rated Power: 1 %
Rated Continuous (RMS) Power @ 14.4V:
300W RMS x 1 @ 4Ω
400W RMS x 1 @ 3Ω
500W RMS x 1 @ 2Ω
Rated Continuous (RMS) Power @ 12.5V:
235W RMS x 1 @ 4Ω
300W RMS x 1 @ 3Ω
410W RMS x 1 @ 2Ω
Recommended Fuse Value (Type): 50A (MAXI or AGU)
Minimum Copper Power/Ground Wire Gauge: 4 AWG
Dimensions (LxWxH):
7.83" x 7.68" x 2.15" (199 mm x 195 mm x 53 mm)
Net Weight: 4.8 lbs. (2.18 kg)
JX1000/1d specifications:
Amplifier Topology: Class D
Power Supply: Unregulated PWM switching type
Frequency Response: 20 - 150 Hz (+/– 1 dB)
Signal to Noise Ratio:
>75 dBA referred to highest rated power, >45 dBA referred
to 1W (20 Hz - 20 kHz noise bandwidth)
Damping Factor: >1000 @ 4 ohms
THD + Noise @ Rated Power: 1 %
Rated Continuous (RMS) Power @ 14.4V:
500W RMS x 1 @ 4Ω
750W RMS x 1 @ 3Ω
1000W RMS x 1 @ 2Ω
Rated Continuous (RMS) Power @ 12.5V:
500W RMS x 1 @ 4Ω
700W RMS x 1 @ 3Ω
900W RMS x 1 @ 2Ω
Recommended Fuse Value (Type): 80A (MAXI or ANL)
Minimum Copper Power/Ground Wire Gauge: 4 AWG
Dimensions (LxWxH):
10.94" x 7.68" x 2.09" (278 mm x 195 mm x 53 mm)
Net Weight: 7.0 lbs. (3.18 kg)
Due to ongoing product development, all specifications are subject to
change without notice.
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