JL Audio W7AE, Owner'S Manual

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Input Sensitivity “Gain” Setting Guide
for JL Audio Subwoofer Amplifiers
Following the directions below will allow you to easily adjust the input sensitivity of the amplifier(s), using commonly
available equipment. Properly setting levels according to this procedure will result in optimum amplifier performance
and improved system reliability.
Step 1:
Disconnect the speaker(s) from the amplifier.
Step 2:
Turn “Off” all processing on the source unit and
the amplifier (bass/treble, loudness, EQ, etc.).
Step 3:
Turn the input sensitivity control on the amplifier
all the way down. If there is a sensitivity range
switch, set it to the “low” position.
Step 4:
Set source unit volume to 3/4 of full volume.
This will allow for reasonable gain overlap
with moderate clipping at full volume.
Step 5:
Cross-reference the amplifier model used and
impedance load per channel on the chart below
to determine the target output voltage.
Step 6:
Verify that you disconnected the speakers before
proceeding. Play a track with an appropriate sine wave
(within the frequency range to be amplified) at 3/4
source unit volume. Selecting the source unit’s “Repeat
Track” feature (if applicable) will be helpful in this step.
Step 7:
Connect the AC voltmeter to the speaker output
of the amplifier.
Step 8:
Increase the input sensitivity control until the desired
voltage (determined in Step 5) is delivered. If multiple
subwoofer amps are being used, set each one to the same
exact voltage and you have also level matched them. On an
amplifier with a sensitivity range switch, if excessive voltage
is read with the control at minimum (full counterclockwise),
switch the “Input Voltage” to “High” and re-adjust.
Step 9:
Once you have adjusted each amp to its maximum
unclipped output level, turn down the volume of the
source unit and turn it off. Reconnect all the speakers,
turn the source unit on and proceed to adjust the
level balance between the subwoofer and satellite
amplifiers. This is accomplished by listening to the
system at a moderate level and turning DOWN the
input sensitivity controls of amplifiers that are playing
too loudly. Do NOT increase the input sensitivity of
any amplifier as this will defeat the purpose of this
procedure by permitting excessive clipping (distortion).
Necessary Equipment
• AC Voltmeter (Digital display recommended)
• A low-frequency (40 or 50 Hz) sine-wave test tone recorded at 0dB reference level.
Do not use attenuated test tones (-10dB, -20dB, etc.).
The Nine-Step Procedure:
Amplifier Voltage Chart
Impedance
HD750/1 HD1200/1 Slash 600/1v3 Slash 1200/1v3 XD600/1v2 JX500/1D JX1000/1D
3Ω
47.4V
(750W)
60.0V
(1200W)
42.4V
(600W)
60.0V
(1200W)
38.7V
(500W)
34.6V
(400W)
47.4V
(750W)
1.5Ω
33.5V
(750W)
42.4V
(1200W)
30.0V
(600W)
42.4V
(1200W)
not
recommended
not
recommended
not
recommended
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