Array Build Strength Considerations - Electro-Voice X1-212/90 Installation Manual

X-LINE ADVANCE Systems
Double grid pick points:
Always attach the two grid pick points at the front-most and rear most attachment points on
the grid.
With the loudspeakers attached in the A position (2g), the maximum down tilt can be
obtained.
With the loudspeakers attached in the B position (2h), moderate down-tilt and up tilt can be
obtained.
With the loudspeakers attached in the C position (2i), the maximum up tit can be obtained.
The user must adjust the front and back hoist motors to achieve the angle reported by LAPS 3.
Double grid pick points plus a pull-up to the grid:
Using a pull-up to the grid enables the loudspeaker to be lifted off the dollies with the boxes
hanging straight at 0º, then pull the boxes their correct angle using a hoist in the pull-up
assembly.
The X12PU-BGK is used at the bottom of the array.
Always attach the two grid pick points at the front-most and rear most attachment points on
the grid.
Always attach the loudspeakers in the A position, furthest away from the pick point (2j).
It is not recommended to use a pull-up to the grid with the loudspeakers in the B position (2k)
or the C position (2l). Because the B and C positions are so close to the pull-up attachment
point on the grid, excessive forces result in the pull-up assembly.
With large arrays, it is possible for a single grid pick point to be in a safe condition once the
pull-up is pulled into compression, but the user would pass through an unsafe condition while
building an array. Therefore we recommend using two grid pick points to avoid the possibility
of an unsafe condition.
For large arrays, the force required to pull the rear rigging of all boxes into compression may
exceed the pull-up assembly maximum rating. If this occurs, it may be necessary to pin several
boxes at the top of the array at fixed angles. If so, LAPS 3 will return a message telling the
user how many boxes to fix pin.
For more information, see .
6.7.3

Array build strength considerations

LAPS 3 reports when the working-load limits for any of the elements in the array are
exceeded. Having an understanding of the structural advantages and disadvantages of
different array build configurations allows the user to select the best option to meet their
needs.
Comparing array structure strengths shows the same array constructed in four (4) different
ways: single grid pick point, single double grid pick points, double grid pick points with a pull-
up to the grid, and single pick point with a pullback to venue. Because the array construction
is different, the forces throughout the array are different. This results in different structural
ratings.
2015.04 | 02 | F.01U.310.953 Installation Manual Electro-Voice