JBL VTX Series, Manual

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VTX A 12 | Rigging Manual
11.5 WHEN DO I NEED A PULL-BACK?
Pull-backs are best suited for when the center of gravity (CoG) of an array falls outside the footprint of the Array Frame. Long, curved
arrays with a large down angle typically qualify. When LAC-3 detects this condition it displays an error to indicate that the array frame
alone cannot achieve the down angle needed for the design (LAC - Example 1). Using an A12 Suspension Bar as a bottom frame can
move the array CoG between the two suspension points, enabling almost any down angle to be achieved (LAC - Example 2).
The two suspension points (motors) are used to adjust the array angle In this scenario, so the Array Frame’s pick-point flexibility is not
needed and a Suspension Bar can be used for the top frame, as well as on the bottom. This yields the same outcome with some weight
and cost savings (LAC - Example 3).
Center of Gravity Suspension Points
Invalid CG Location
LAC - Example 1 LAC - Example 2
LAC - Example 3
Center of Gravity Suspension Points
Center of Gravity Suspension Points