Harman JBL GX-A604 Manuel Du Propriétaire page 20

set the crossover controls
gX-a604: 4-channel operatIon
Input Mode switch: Set the Input Mode switch in the "4CH" position.
Front Crossover Filter switch: Set the Front Crossover Filter switch in the "ON" (high-pass) position. This will limit the amount of low-frequency
energy sent to the speakers, significantly reducing distortion and preventing the speakers from damage. Exception: If you have connected large
full-range speakers (6" x 9" or larger) that can handle significant bass to the amplifier's front channels and you are not using a subwoofer in the
system, set the Front Crossover Filter switch to the "OFF" (full-range) position.
Rear Crossover Filter switch: Set the Rear Crossover Filter switch in the "HP" (high-pass) position. This will limit the amount of low-frequency
energy sent to the speakers, significantly reducing distortion and preventing the speakers from damage. Exception: If you have connected large
full-range speakers (6" x 9" or larger) that can handle significant bass to the amplifier's front channels and you are not using a subwoofer in the
system, set the Rear Crossover Filter switch to the "FLAT" (full-range) position.
Rear Crossover control: When the Rear Crossover switch is set in
6" and 5" Speakers 4" and Smaller Speakers
the "HP" position, the Rear Crossover control determines the frequency
where the low frequencies sent to the speakers begin to be reduced in
volume.
When running the amplifier in the 4-channel mode you should set the
Rear Crossover control according to the size of the speakers connected
to the amplifier channels – the smaller the speakers the higher you
need to set the control to protect the speakers from damage. After
initially setting the crossover frequency, listen to music with strong bass
that you are familiar with. If the speakers sound distorted or distressed, move the crossover frequency control to a higher setting to eliminate the
distortion/ distress. The illustration to the right shows the recommended crossover filter frequency ranges for different speaker sizes.
gX-a604: 3-channel operatIon
Low-Pass Operation:
Input Mode switch: Set the Input Mode switch in the "4CH" position.
Subwoofers and Woofers
Front Crossover switch: Set the Front Crossover switch in the "ON" (high-pass) position. This will limit the
amount of low-frequency energy sent to the speakers, significantly reducing distortion and preventing the
speakers from damage.
Rear Crossover Filter switch: When connecting a subwoofer or woofer to the rear channels, set the Rear
Crossover Filter switch in the "LP" (low-pass) position. This will limit the amount of high-frequency energy sent
to the woofers or subwoofer, improving the clarity of vocals and other midrange sounds.
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