Page 8 of 18 RD0465(A) JFL SERIES OWNER’S MANUAL
NOTE: Bass performance is often highly program- or venue-dependent, as well as subjective as
to quantity and quality. For this reason the type, quantity, and disposition of subwoofers may vary
considerably with the application. The quantity recommendations below are for general purposes,
providing a balanced system for most music applications. Quantities may need to be adjusted up
or down for specific situations.
4.3.2 JFL118
Subwoofers
JFL118 subwoofers are designed to complement the JFL210 loudspeakers to both extend the low
frequency response and provide more output for the upper low frequencies. JFL118 subwoofers
may either be ground stacked, flown as part of a JFL210 array, or flown separately alongside a
JFL210 array.
A general recommendation is to use JFL210s and JFL118s in a 2:1 ratio.
4.3.3 Suspending
JFL118
Subwoofers
The JFL118 enclosure rigging is designed to directly couple to an FB121 Fly Bar and JFL210
enclosures. As such, the JFL118 can be rigged seamlessly with JFL210s. See the
FB121 Rigging
& Ground Stack Instructions
for more detailed information on rigging a JFL118.
The JFL118s should be the uppermost enclosures when flown as part of a JFL210 array. In this
application, the JFL118s are suspended flat-fronted, with the JFL210s suspended below in a
constant curvature array. When flown separately, JFL118s should be flown so that the spacing
between the line of JFL118 enclosures and JFL210 enclosures is less than 1 m / 3.3 ft.
4.3.4 Signal Delay on Subwoofers
If JFL118s are flown or stacked with JFL210s as configured in the Line Array Wizard, use the
factory signal delay settings.
For other configurations or subwoofers, it will usually be necessary to determine the signal delay
settings by measurement.
5. ARRAY OPERATION
5.1 OVERVIEW
The operation of a JFL Series system involves:
1. Understanding the principles on which it operates.
2. Knowing how to electronically configure it for a specific task.
5.2 ENGINEERING DESIGN
The
JFLWizard
software uses the fixed splay angle of the enclosure and the desired coverage
pattern to determine the quantity of enclosures in the array that will optimize coverage for the
audience distances and angles within the venue. The basic principle to remember is that more
enclosures provide greater vertical coverage and fewer enclosures provide less vertical coverage.
5.3 SYSTEM BLOCK DIAGRAM
The JFL118 powering mode is single-amp only. The JFL210 has two powering modes: single-
amp and bi-amp. A JFL210 operated in single-amp mode only requires a high pass filter for low
frequency excursion protection. This may be implemented in a DSP (Digital Signal Processor),
equalizer, or amplifier with integrated high pass filter. The recommended filter is 60 Hz, 12 to 24
dB Butterworth.
