SETTING UP THE GTi AMPLIFIER
SETTING THE CROSSOVERSETTING INPUTSETTING PHASESETTING DBO
IMPORTANT: If you plan to use theSENSITIVITY1. Initially set the PHASE control to 0.!DBO (or Dynamic Bass Optimizer) is
A3000GTi to drive full-range speakers,NOTE: You can use the suppliedPlay a favorite audio track that has a 12dB/octave high-pass filter with
set the crossover mode switch to FLATREMOTE LEVEL control to fine-tune significant bass output.variable frequency (20Hz to 80Hz)
and skip to the next section, OSettingthe input sensitivity or to adjust the2. Continue listening to the music andand variable boost (0 to +12dB) at
Input Sensitivity.�level of the bass according to the have another person slowly adjustthe cutoff frequency.
program material after the amplifierOsthe PHASE control towards 180! and
1. Depending on your system plan, LEVEL control has been set properly.back to 0! again. NOTE: During DBO adjustment, you can
Connect the remote moduleOs attached
set the A3000GTiOs crossover mode3. Repeat Step 2 as needed until youaudition the effect by setting the DBO
cable to the REMOTE LEVEL (RJ45) jack
switch to LP (low-pass) or HP (high-find a setting that produces theswitch to OFF and then back to ON.
pass). The A6000GTi is a low-passon the amplifierOs input panel. Startmost mid-bass output.
with the REMOTE LEVEL Control in its
amplifier only, designed to drive
NOTE: The A3000GTi can be used
maximum (clockwise) position.
subwoofers. No crossover switch NOTE: For applications using multipleto drive a pair of stereo mid-bass
is provided.
GTi amplifiers where the highest SPL speakers. In this case, use the DBO
2. The crossover slope has two 1. Initially, turn the amplifierOs LEVELis desired at a single point in the to set the high-pass filter (from 20Hz to
settings: 12 (dB per octave) or control to the minimum (clockwise)vehicle (i.e., SPL competition), adjust80Hz) and use the crossover to set the
24 (dB per octave). Select the position.the PHASE controls on all amplifiers low-pass filter (from 80Hz to 320Hz).
slope that best suits your taste, but2. Reconnect the (�) negative lead toso all speakers are in phase at the
consider that a steeper low-pass your vehicleOs battery. Apply powermicrophone position. This will provide
For a vented box where a subwoofer
filter will make the subwoofersto the audio system and play athe highest SPL when measured with
is prone to overexcursion below the
sound less directional (since morefavorite music track. an SPL meter.
tuned frequency, set DBO to ON and
midrange will be filtered from the3. Increase the source unitOs volume
set the DBO HP FREQ control 10Hz
signal). A steeper high-pass filtercontrol to the maximum listening
below the boxOs resonant (tuned)
will reduce a small speakerOs position. Slowly turn the amplifierOsDBO HP FREQ ControlHP FREQ
frequency (e.g., 30Hz for a vented
unnecessary cone excursion at LEVEL control counterclockwise and(adjusts cut-off
box tuned to 40Hz). Power typically
the lowest frequencies, which observe the I/OPT and E/OPT LEDsfrequency)
wasted in this region will now be
will increase power handling (on the amplifierOs top). dB80Hz 20Hz
conserved and instead be available
and reduce distortion.
Y In the bridged or 2-channel mode,0for frequencies the enclosure can
3. Set the A3000GTiOs HP FREQ controlat the ideal setting, the E/OPT LED
reproduce. Use the DBO BOOST
�3
to allow the speakers to make should flash on musical peaks tocontrol to boost the bass at the set
as much bass as possible while indicate the amplifier is producing
�6frequency by as much as 12dB, as
minimizing distortion caused by maximum voltage. If the I/OPT LED
shown in Figure 13.
small speakers trying to reproduceflashes in bridged mode, this �9
the lowest frequencies. The best indicates the speaker systemOs
�12For a sealed enclosure, use DBO to
setting is one where the speakersimpedance is lower than 2 ohms2080Freq. (Hz)
enhance the middle of the bass region.
produce crisp, clear impact withoutand the amplifier should be
Set DBO to ON, and then set the DBO
being overdriven.configured in the parallel mode. DBO BOOST ControlBOOST
HP FREQ control to 35Hz to 40Hz.
4. For either amplifier, set the LP FREQY In the parallel mode, at the ideal(adjusts boost amount
Adjust the DBO BOOST control for a
control so vocal information is notsetting, the I/OPT LED should at cut-off frequency)
big and full bass sound. Alternatively,
reproduced by the subwoofers, andflash on musical peaks to indicatedB MIN MAX
for a tighter-sounding bass, set the
the subwoofersO sound blends withthat the amplifier is producing12DBO HP FREQ control between 45Hz to
the sound of the midrange speakersmaximum current.
50Hz and also adjust the DBO BOOST
without any missing information.6
control according to your preference.
If either the I/OPT or E/OPT LED is 0
NOTE: The LP FREQ control can be on steadily, the amplifier is being
For an infinite baffle application,
set to any frequency between 32Hz overdriven and your speakers may �6
set DBO to ON, and then set the
and 320Hz. be in jeopardy. Turn the LEVEL
�12HP FREQ control to the speakerOs Fs
control back slightly until the I/OPT or2080Freq. (Hz)
value (to keep the subwoofer from
E/OPT LED flashes on musical peaks.
trying to create bass below the
Figure 13. Frequency response curves
show typical DBO control ranges forresonant frequency). Adjust the DBO
the JBL A6000GTi or A3000GTi amplifier.BOOST control according to your taste.
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ACEC
