JL Audio JX250/1D Owner's Manual page 8

LOW-PASS FILTER CONTROL
The JX monoblock employs a 12dB/octave
low-pass active filter for its internal channel. This
feature is designed to attenuate frequencies above
its filter frequency, so that the system's subwoofers
do not reproduce any audible mid-range content.
The low-pass filter is fully variable between
50 Hz and 200 Hz via the "Filter Frequency"
control knob. 80 Hz (as shown in the diagram
below) is a good starting point for system tuning.
8
"PREOUTS"
The JX monoblock incorporates a pass-
through preamp output (Preouts) section,
designed to make multiple amplifier systems easy
to set up. This section consists of a pair of RCA-
type jacks marked "Preouts".
These preamp outputs deliver the same signal
that is being fed to the Low-Level inputs. (If the
input signals are full-range, the preamp outputs
will be full-range). This signal is not affected by
the bass boost or Filter processing selected for the
amplifier.
I M P O R TA N T !
The "Preouts" of the JX250/1D and JX500/1D
will not pass signals from the Hi-Level inputs.
The JX1000/1D will pass signals from the
Hi-Level inputs and will attenuate them to
Low-Level.
JL Audio