X-Array™ Loudspeaker Systems
This configuration cannot be implemented with a
grid like that shown in
Figure 8
because the grid
cannot be balanced.
To attach a pull-up line to the bottom enclosure
in an array column, a long Xrsl rigging strap
(or
other similar strap) may be attached to the two
round cutouts in the rear rigging track as shown
in
Figure 18
. A variety standard rigging hardware
components (such as shackles, threaded chain
connectors, carabiners, etc.) may be used to se-
cure the pull-up line to the Xrsl wire-rope strap.
The attachment hardware should have a diameter
of at least 9.5 mm (.375 in.) to eliminate the possi-
bility of kinking the wire rope of the Xrsl. Attaching
the pull-up to only one of the round cutouts in the
rear track is not recommended because it would
cause the column to twist.
CAUTIONS for Pull-Up Lines: When a grid is
used, the Xrhg grid hinge is used to attach the
back of the top enclosure in a column to the back
of the grid, while the Xrss or Xrsl rigging straps
are used to attach the front. If too much force is
applied on a pull-up line, the chain on the Xrhg
grid hinges could go slack, shifting all of the
weight of the entire array column to the front rig-
ging straps. This condition presents two problems
of serious concern. The first concern is that, when
all of the weight shifts to the front straps, the grid
will become unbalanced, resulting in the front of
the grid tilting down and the back tilting up. This
imbalance could cause a sudden shift in the load
that could be dangerous. If multiple grids are
coupled together horizontally and one grid be-
comes unbalanced, there could be dangerous
twisting forces between the unbalanced grid and
adjacent balanced grids. The second concern is
that, when all of the weight shifts to the front
straps, a safety factor of 8:1 may not be main-
tained for the front rigging straps.
When a grid is not used, the Xrhp pickup hinge
is used to attach the back of the top enclosure
to building structural supports, while custom wire-
rope assemblies are used to support the top en-
closure front. If too much force is applied on a
pull-up line, the chain on the Xrhp pickup hinges
could go slack, shifting all of the weight of the en-
tire array column to the front wire-rope assem-
blies. The concern here is that, when all of the
weight shifts to the front straps, a safety factor of
8:1 may not be maintained for the front wire-rope
assemblies.
THE USER IS CAUTIONED TO TENSION THE
PULL-UP LINE ONLY UNTIL THE SLACK IN THE
FRONT RIGGING STRAPS HAS BEEN RE-
MOVED. NEVER PULL UP ENOUGH TO CAUSE
THE CHAIN OF ANY Xrhg GRID HINGES OR
Xrhp PICKUP HINGES TO GO SLACK.
3. RIGGING-STRENGTH RATINGS, SAFETY
FACTORS, AND SPECIAL SAFETY CONSIDER-
ATIONS
3.1 Working Load Limit and Safety Factors
Definitions: The structural ratings for all of the
X-Array™ rigging components and complete
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