JL Audio XD600/1v2 オーナーマニュアル

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The “Infrasonic Filter” is a 24 dB/octave high-

pass filter, with a fixed cutoff frequency of 30 Hz. 
This filter is designed to conserve amplifier power 
and protect subwoofer systems, without audibly 
degrading the sub-bass output.

With ported enclosures, the use of the 

“Infrasonic Filter” is highly recommended to 
protect the speaker(s) from excessive excursion 
below enclosure tuning.

With sealed enclosures, the use of the filter 

is less necessary, but can still help protect the 
speaker system from excessive excursion.

The “Infrasonic Filter” can be completely 

defeated by selecting the “Off” position on its 
switch. This bypasses all signal from flowing 
through the circuit.

With the addition of the optional Remote 

Level Control (HD-RLC), you can control the 
subwoofer volume from the front of the vehicle.

The HD-RLC connects to the jack labeled 

“Remote Level Control” on the Connection 
Panel of the amplifier using a standard telephone  
cable (supplied with the HD-RLC). If desired, 
multiple XD (and HD) amplifiers can be 
controlled from a single HD-RLC controller using 
a single-line, four-wire phone line splitter and 
multiple phone cables.

When connected to the amplifier, the HD-RLC 

operates as follows: At full counter-clockwise 
rotation, the audio will mute completely. At full 
clockwise rotation the level will be the same as if 
the HD-RLC was not connected at all. In other 
words, it operates strictly as a level attenuator.