Electro-voice XI-A User Manual

Xi-A Series Loudspeaker System
Flying Manual

ELECTRO-VOICE® Xi-A Rigging Manual

Table of Contents

0. Rigging-Safety Warning.......................................................................................................................................... 2

I. Introduction ......................................................................................................................................................... 3

1.1 The Flying Xi-A Loudspeaker Systems .................................................................................................... 3

II. Basic Xi-A Rigging Primer....................................................................................................................................... 3

2.1 Anatomy of an Xi-A Flying System........................................................................................................... 3

2.2 The Rigging Hardware ............................................................................................................................. 4

2.3 The Xi-A Flying Concept .......................................................................................................................... 7

2.3.1 Accoustical Considerations ...................................................................................................... 7

2.3.2 Practical Considerations .......................................................................................................... 8

III. Associated Rigging Hardware for Flying Xi-A Loudspeaker Systems .................................................................. 10

3.1 Grids and Associated Rigging Hardware ............................................................................................... 10

IV. Strength Ratings, Safety Factors, and Special Safety Considerations................................................................. 10

4.1 Strength Ratings and Safety Factors ..................................................................................................... 10

4.2 Special Safety Considerations for Xi-A Loudspeaker Arrays.................................................................. 12

4.3 Special Safety Considerations for Rigging Strap Assemblies................................................................. 14

4.3.1 Redundant Attachment Points................................................................................................ 14

4.3.2 Special Considerations for Polyester Webbing....................................................................... 14

4.4 Special Safety Considerations for Grid & Building Structural Supports .................................................. 14

V. Rigging Inspection and Precautions ..................................................................................................................... 15

5.1 Xi-A System Components...................................................................................................................... 15

5.1.1 Xi-A Loudspeaker Systems .................................................................................................... 15

5.1.2 Rigging Strap Assemblies ...................................................................................................... 15

5.2 Associated Hardware ............................................................................................................................. 15

5.2.1 Grid Assembly........................................................................................................................ 15

5.2.2 Chain Hoists........................................................................................................................... 15

5.2.3 Building Structural Supports...................................................................................................15

5.2.4 Mechanical Components........................................................................................................ 16

VI. Appendices ....................................................................................................................................................... 17

Appendix A Xi-A Rigging Accessories ........................................................................................................ 17

Appendix B References ............................................................................................................................. 17

B.1 Accoustical References ............................................................................................................ 17

B.2 Mechanical References............................................................................................................ 18

ELECTRO-VOICE® Xi-A Rigging Manual1

0. Rigging-Safety Warning

This document details general rigging practices appropriate to the entertainment industry, as they
would apply to the rigging of Electro-Voice Xi-A loudspeaker systems. It is intended to familiarize
the reader with standard rigging hardware and techniques for suspending Xi-A loudspeaker
systems overhead. Only persons with the knowledge of proper hardware and safe rigging
techniques should attempt to suspend any sound systems overhead. Prior to suspending any
Electro-Voice Xi-A loudspeaker systems overhead, it is essential that the user be familiar with the
strength ratings, rigging techniques and special safety considerations outlined in this manual. The
rigging techniques and practices recommended in this manual are, of necessity, in general terms
to accommodate the many variations in loudspeaker arrays and rigging configurations. As such,
the user is expressly responsible for the safety of all specific Xi-A loudspeaker array designs and
rigging configurations as implemented in practice.

All the general rigging material contained in this manual is based on the best available
engineering information concerning materials and practices, as commonly recognized in the
United States, and is believed to be accurate at the time of the original printing. As such, the
information may not be directly applicable in other countries. Furthermore, the regulations and
requirements governing rigging hardware and practices may be superseded by local regulations.
It is the responsibility of the user to ensure that any Electro-Voice loudspeaker system is
suspended overhead in accordance with all current federal, state and local regulations.

All specific material concerning the strength ratings, rigging techniques and safety considerations
for the Xi-A loudspeaker systems is based on the best available engineering information
concerning the use and limitations of the products. Electro-Voice continually engages in testing,
research and development of its loudspeaker products. As a result, the specifications are subject
to change without notice. It is the responsibility of the user to ensure that any Electro-Voice
loudspeaker system is suspended overhead in accordance with the strength ratings, rigging
techniques and safety considerations given in this document and any manual update notices. All
non-Electro-Voice associated hardware items necessary to rig a complete Xi-A loudspeaker array
(grids, chain hoists, building or tower supports and miscellaneous mechanical components) are
the responsibility of others.

Electro-Voice
June, 2004

The exclamation point within an equilateral triangle is intended to alert the user to
the presence of important operating and maintenance (servicing) instructions in the
literature accompanying the appliance.

ELECTRO-VOICE® Xi-A Rigging Manual 2

I. Introduction

1.1 The Flying Xi-A Loudspeaker Systems

The flying versions of the X-Array Install™ loudspeaker systems all incorporate a unique two-point
flying system that consists of two lengths of heavy-duty, L-track, aircraft-type rigging hardware on
the top and bottom of each enclosure. The design allows arrays to be assembled very quickly, and
offers such flexibility in the vertical angling of the cabinets that pull-up points are usually
unnecessary. Furthermore, the cabinets may be oriented with the rigging track on the top and
bottom of the enclosure or on the sides of the enclosure. For fire safety and additional structural
strength in both flying orientations, top-to-bottom and side-to-side metal straps link the rigging
track assemblies inside the enclosure. In addition, a line of flying hardware accessories is
available for use with the Xi-A loudspeaker systems from Sound Manufacturing, Inc. (See
Appendix A for available rigging accessories.)

II. Basic Xi-A Rigging Primer

2.1 Anatomy of an Xi-A Flying System

A basic two-cabinet flying system is shown in Figure 2.1a, illustrating the integral components that
make up a typical Xi-A loudspeaker array, where the enclosures are oriented with the rigging
hardware on the top and bottom of the enclosures. A similar two cabinet system is shown in
Figure 2.1b where the enclosures are oriented with the rigging hardware on the sides of the
enclosures. The top cabinets are the starting points for constructing the arrays in both examples.
These cabinets are first secured to a grid through the use of two grid straps per cabinet. (The
GS-1B grid straps are recommended.) The Xi-A enclosures are equipped with two pieces of track,
which have multiple positions where the grid straps may be attached. The linear positioning of the
attachment points along the track (front-to-back) determines the vertical angling of the enclosure.
The remaining ends of the grid straps are then secured to cross members of a grid. The relative
positioning of the straps along the cross members of the grid (front to back) determine the relative
horizontal splay angle between two adjacent columns of enclosures. A second row of enclosures
may be added below the original two by utilizing linking straps that attach from the lower track
pieces of the top enclosures to the upper track pieces of the bottom enclosures. (LS-1B, LS-2B
and LS-3B linking straps, each a different length, are recommended.) Additional cabinets may be
hung in succession in this fashion, as long as the load on any of the enclosures or rigging straps
does not exceed their working-load-limit rating. The loudspeaker/array/grid assembly is then
raised into position by a motorized chain hoist (or hoists) of sufficient load rating. Note that the
weight of such an array can be quite substantial and the building structural supports to which the
hoists are attached must be capable of supporting such a load with a sufficient safety factor. In
permanent installations, the chain hoists are often eliminated, with the grid assembly being
secured directly to the building structure. The reader is referred to Chapters IV and V of this
manual for a detailed discussion of the structural strength ratings of the Xi-A loudspeakers and L­track rigging accessories, and information on how to safely suspend Xi-A loudspeaker systems
overhead.

ELECTRO-VOICE® Xi-A Rigging Manual3

2.2 The Rigging Hardware

The Xi-A flying system utilizes the highest-tech aircraft-type hardware available for securing heavy
loads. Four pieces of heavy-duty, aircraft-type, “L-Track” rigging hardware, specially machined
extrusions of very-high-strength, aluminum-alloy material, are mounted in each enclosure. The
track pieces are secured to high-strength, aluminum-alloy brackets that are an integral part of the
Xi-A flying enclosure. Enclosure dimensions and rigging track locations are shown in Figure 2.2 for
all of the Xi-A loudspeaker systems. For attachment to the track, the GS-1B grid-strap assembly,
the LS-1B, LS-2B and LS-3B linking strap assemblies, the RS-1B double-stud, swivel-ring fitting
assembly and the RS-2B single-stud, swivel-ring fitting assembly are available from Sound
Manufacturing, Inc. (See Appendix A for details.) These assemblies, shown in Figure 2.3, have
been specifically designed for optimal implementation of the Electro-Voice L-track flying systems.
The GS-1B includes a double-stud, swivel-ring fitting on one end for attachment to the enclosure
and a safety hook on the other end. The safety hook may be attached to 5/8-inch shackles, or
may be secured directly to the grid through a 7/8-inch diameter hole in the grid bar-stock material.
The LS-1B, LS-2B and LS-3B have double-stud swivel-ring fillings on both ends for linking two Xi­A enclosures together. The GS-1B, LS-1B and LS-2B rigging straps utilize polyester webbing strap
material. Polyester webbing was chosen for its tremendous strength and because of its dynamic
flexing capabilities. The force from any sudden jolt or shift in the load is absorbed by the strap
rather than transmitted directly to the loudspeaker enclosure. In addition, polyester webbing is a
flexible material that is easy to handle.

Hoist Motor

Wire Rope Sling

5/8” Shackle

Grid

GS-1B

LS-3B

Hoist Motor

Wire Rope Sling

5/8” Shackle

Grid

GS-1B

LS-1B

Figure 2.1a:

Top and Bottom of the Enclosures

ELECTRO-VOICE® Xi-A Rigging Manual 4

Rigging Hardware on the

Figure 2.1b:

Sides of the Enclosures

Rigging Hardware on the

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Xi-A Dimensions, Weight, Rigging Location, and Center of Gravity

ELECTRO-VOICE® Xi-A Rigging Manual5

GS-1B Linking Strap (with Double-Stud Fitting)

LS-1B Linking Strap (with Double-S tud Fitting)

LS-2B Linking Strap (with Double-S tud Fitting)

LS-3B Linking Strap (with Double-S tud Fitting)

RS-1B Swivel-Ring Fitting (with Double-Stud Fitting)

RS-2B Swivel-Ring Fitting (with Single-Stud Fitting)

LOCKING
RING

Figure 2.4a:

LOCKING
PIN

STUD
FEET

FITTING
BODY

RS-1B Double-Stud Fitting

LOCKING
PIN

FITTING

STUD
FOOT

BODY

Figure 2.3:

Xi-A L-Track Rigging

Figure 2.4b:

RS-2B Single-Stud Fitting

Accessories

The user is cautioned, however, that in certain permanent-installation applications, the polyester
material may not meet local fire regulations. The user is also cautioned that polyester material will
deteriorate with extended exposure to ultraviolet light (direct sunlight) or to hot, dry environments,
resulting in reduced strength capability. In such instances, wire rope or chain assemblies must be
substituted. The RS-1B double-stud fitting and the RS-2B single-stud fitting both attach to the Xi-A
enclosure’s rigging track, and have swivel rings that are suitable for attachment to various
standard rigging hardware. The user may use the RS-1B and RS-2B to construct wire rope or
chain rigging assemblies. In addition, the Xi-A enclosure’s rigging track will also accept the RS-1B
double-stud swivel-ring fillings and the RS-2B single-stud swivel-ring fillings. The user is cautioned
that the structural strength ratings of the single-stud fittings are approximately one half that of the
double-stud fittings. These lower ratings, however, are completely sufficient for suspending lighter
loads overhead (for example, when flying one or two of the smaller/lighter Xi-A loudspeaker
systems in permanent installations), making the single-stud fittings attractive lower-cost
alternatives to the double-stud fittings. The reader is referred to Chapters IV and V of this manual
for a detailed discussion of the structural strength ratings of the Xi-A loudspeakers and L-track
rigging accessories, and information on how to safely suspend Xi-A loudspeaker systems

ELECTRO-VOICE® Xi-A Rigging Manual 6

overhead. To attach the double-stud, swivel-ring fittings (as shown in Figure 2.4a) to the
enclosure’s rigging track, push in the spring-loaded safety-locking pin and lift the outer locking ring
over the pin. Continue to lift the locking ring until the two studs on the bottom of the fitting are fully
exposed. Insert the two round feet of the studs into the round cutouts in the track and slide the
fitting to the desired position. Center the main body of the fitting over one of the track cutouts, with
the feet located on either side (i.e., with the stud feet positioned directly under the teeth of the
track). Release the outer locking ring. The round protrusion on the bottom of the fitting should lock
into the round cutout in the track with the locking ring retracting to its normal position, allowing the
safety-locking pin to reappear and extend over the locking ring. If the fitting does not lock into the
track, nudge it along the track and wiggle as necessary until it settles into position. If the outer
locking ring does not fully retract, push the ring towards the track until the safety pin reappears
and extends over the locking ring. When locked, the fitting will be immovable in the track and the
locking ring of the fitting may not be lifted. To remove the fitting, reverse the procedure.

ALWAYS CHECK TO MAKE SURE THAT THE FITTING IS SECURELY LOCKED
INTO THE TRACK, AND THAT THE SAFETY PIN IS EXTENDED OVER THE
LOCKING RING BEFORE LIFTING ANY LOUDSPEAKER ENCLOSURE
OVERHEAD.

To attach the single-stud, swivel-ring fittings (as shown in Figure 2.4b) to the enclosure’s rigging
track, remove the safety-locking pin and lift the fitting body over the hole for the locking pin.
Continue to lift the fitting body until the stud on the bottom of the fitting is fully exposed. Insert the
round foot of the stud into a round cutout in the track and slide the fitting to the desired position.
Center the main body of the fitting over one of the track teeth (i.e. with the stud foot positioned
directly under one tooth of the track). Release the fitting body. The body of the fitting should lock
into the round cutouts in the track with the fitting body retracting to its normal position, allowing the
hole for the safety-locking pin to reappear. If the fitting does not lock into the track, nudge it along
the track and wiggle as necessary until it settles into position. If the fitting body does not fully
retract, push the body towards the track until the hole for the safety pin reappears. Install the
safety-locking pin into the hole in the shaft. When locked, the fitting will be immovable in the track
and the body of the fitting may not be lifted. To remove the fitting, reverse the procedure.

ALWAYS CHECK TO MAKE SURE THAT THE FITTING IS SECURELY LOCKED
INTO THE TRACK, AND THAT THE SAFETY PIN IS INSTALLED BEFORE
LIFTING ANY LOUDSPEAKER ENCLOSURE OVERHEAD.

2.3 The Xi-A Flying Concept

2.3.1 Acoustical Considerations

The Xi-A systems lend themselves to easy array construction. All of the Xi-A loudspeaker systems
use the same L-track rigging hardware on the enclosures, and may be oriented with the rigging
track either on the top and bottom of the cabinets or on the sides of the cabinets. All of the full­range Xi-A systems have trapezoidal enclosures, enabling high-density, point-source arrays. The
horns in many of the full-range Xi-A systems are rotatable, allowing the cabinets to be oriented for
optimal physical installation and the coverage pattern to be oriented for optimal acoustic
performance. Many of the Xi-A systems have the same dimensions, facilitating ease of rigging
and a consistent cosmetic appearance. With grilles in place, the Xi-A subwoofer systems are
indistinguishable from the large Xi-A full-range systems, allowing the option of either flying the
subwoofers or stacking them on the floor, or even a combination of the two, while still preserving

ELECTRO-VOICE® Xi-A Rigging Manual7

the uniform appearance of both the ground stack and the flown array. When designing an Xi-A
loudspeaker array, three primary acoustic goals should be kept in mind. First, the array should be
designed so that the acoustic energy is directed at the audience and away from reflecting
surfaces outside the listening area. This maximizes the intelligibility and clarity throughout the
listening area. Second, the array should be designed to achieve even coverage throughout the
audience. This ensures consistent levels and sound quality throughout the listening area. Third,
the array should be designed to achieve the required sound pressure levels throughout the
audience. This also maximizes the intelligibility and clarity throughout the listening area. The key
to achieving these three goals is to select the Xi-A loudspeaker system with appropriate coverage
patterns and acoustic-output capabilities, orient the enclosures and coverage patterns for optimal
array performance, and accurately aim the systems in the array. The reader is referred to
Appendix B.1 for a list of references covering the topics of acoustics and loudspeaker array
design. Because sound coming from numerous loudspeakers should arrive at any seat at the
same time, the speakers in an array should be curved as if mounted on the outside of an
imaginary sphere. The loudspeakers should be close-spaced to minimize lobing and maximize
coupling and each speaker must be accurately aimed. The apparent source then becomes the
single point at the center of the sphere. The horizontal array curve is simply achieved by hanging
the cabinets closely spaced, aimed outward at diverging angles. Achieving the vertical array curve
is a bit more complex to obtain. The Xi-A loudspeaker systems utilize a unique two-point
suspension system (shown in Figure 2.1) that can achieve all of the design criteria for a true point­source array. To tilt an Xi-A loudspeaker system downward, the rigging straps at the top of that
cabinet are shifted along the rigging track towards the rear of the enclosure. To align the top-rear
corner of an Xi-A cabinet with the bottom-rear corner of an Xi-A cabinet above it, the rigging straps
at the bottom of the upper cabinet are shifted along the rigging track until the rear corners of the
adjacent cabinets are in alignment. A number of examples are presented in the following section
that will demonstrate both the mechanical and acoustical aspects of an array design with the Xi-A
loudspeaker systems.

2.3.2 Practical Considerations

The vertical angle of the flying Xi-A loudspeaker system may be adjusted by choosing different
positions of attachment along the rigging track on the cabinet. There are a number of attachment
points allowing for a wide variety of angles. Although the center of gravity is slightly different for
each of the systems, the balancing concept is the same. The further the top attachment point is
towards the back of the cabinet, the greater the downward angle, as shown in Figure 2.5. As the
attachment point is moved forward, the cabinet will have less downward angle and, at the furthest
point forward, will have an upward tilt. This principle holds true when hanging any of the Xi-A
systems in either rigging orientation (rigging track on the top and bottom, or on the sides). Vertical
arrays are constructed by hanging Xi-A systems from one another in succession. Both the
curvature of the array and the angles of the individual cabinets are controlled by the rigging
attachment positions. The shape of the array curve is determined by the position on the lower
track of an already hanging cabinet from which the next cabinet is hung, the further back the
attachment point is on the upper box, the further back the lower cabinet is shifted and, hence, the
greater the curvature of the array. The goal is to have the back, top and bottom edges to adjacent
cabinets in alignment. Hanging one cabinet from another affects the angle of the first. This is best
demonstrated in an example. In Figure 2.6a, one Xi-A enclosure is hung so that it points straight
ahead and a second is added below. The addition of the second enclosure causes the top cabinet
to point upward. Shifting the upper attachment point of the first cabinet back, as shown in Figure

2.6b, counteracts the additional load and results in the upper cabinet pointing straight ahead

ELECTRO-VOICE® Xi-A Rigging Manual 8

again. Note that this change has no affect on the angle of the lower cabinet. Additional Xi-A
enclosures may be hung in succession in this fashion, creating a tall vertical line array (as long as
the working-load limit of all of the mechanical components are not exceeded and a sufficient
safety factor is maintained throughout the array). With the Xi-A loudspeaker systems oriented with
the rigging track on the top and bottom of the cabinets, a short rigging strap is used between the
cabinets to minimize the spacing between the systems. Typically, the LS-3B is used for this task.
If, however, Xi-A enclosures having different dimensions are hung from one another (an Xi-1122A
suspended beneath an Xi-1191AF, for example), a longer strap would be required to
accommodate the different distances In width between the rigging tracks. In this instance, the LS­1B could be employed. Another option would be to use two RS-1B double-stud swivel-ring fittings
linked with a threaded-chain connector or a carabineer snap hook. (The RS-2B single-stud-ring
fittings could be used in lighter-weight applications.) With the Xi-A loudspeaker systems oriented
with the rigging track on the sides at the cabinets, a longer rigging strap is required between the
cabinets to minimize the spacing between the systems. Typically, the LS-1B is used for this task.
If, however, Xi-A enclosures having different dimensions are hung from one another (an Xi-1122A
suspended beneath an Xi-1191AF, for example), a longer strap would be required to
accommodate the different distances in width between the rigging tracks. In this instance, the LS­2B could be employed. Another option would be to use two RS-1B double-stud-ring fittings linked
with a wire-rope assembly. (The RS-2B single-stud ring fittings could be used in lighter-weight
applications.)

Figure 2.5a:

Enclosure Oriented so the

Rigging is on the Top or Bottom

Figure 2.5b:

Enclosure Oriented so the

Rigging is on the Sides

Figure 2.6a:

Adding a Bottom Enclosure

Affects the Top Enclosure Angle

Figure 2.6b:

Change the Rigging

Attachment Point on Top Enclosure to

Readjust Top Enclosure Angle

ELECTRO-VOICE® Xi-A Rigging Manual9

III. Associated Rigging Hardware for Flying Xi-A
Loudspeaker Systems

3.1 Grids and Associated Rigging Hardware

The GS-1B, LS-1B, LS-2B, LS-3B, RS-1B and RS-2B rigging accessories described throughout
this manual for use with the flying Xi-A loudspeaker systems are available from Sound
Manufacturing, Inc. (See Appendix A for details.) Electro-Voice does not manufacture grids or any
of the other associated hardware required for suspending Xi-A loudspeaker arrays overhead. In
the case of both permanent-installation and touring sound applications, it is generally most
efficient and cost effective to design a support system specific to the application, taking into
account the loudspeaker array requirements. In some permanent installations, it may even be
possible in some circumstances to eliminate the grid and secure the loudspeakers directly to the
building structural supports. The sound-system designer is instructed to evaluate each individual
circumstance and design a support system tailored to the specific application. To aid rigging
designers, the user is directed to two companies that manufacture and sell generalized and semi­custom rigging hardware and accessories for flying loudspeaker systems - ATM Fly-Ware™ and
Sound Manufacturing, Inc. (See Appendix A for details on how to contact these companies.)

Attention: All associated non-Electro-Voice rigging hardware used for suspending
any X-Array Install™ (Xi-A) loudspeaker systems overhead is expressly the
responsibility of others.

IV. Strength Ratings, Safety Factors and Special Safety
Considerations

4.1 Strength Ratings and Safety Factors

Electro-Voice provides strength ratings for the Xi-A loudspeaker systems in terms of the working­load limit rating based on an 8:1 minimum safety factor. The working-load-limit rating is defined as
the maximum allowable force that may be applied to the mechanical component. The rated safety
factor is defined as the ratio of the ultimate-break-strength rating to the working-load-limit rating.
The ultimate break-strength rating represents the force applied to a mechanical component at
which the component will structurally fail. As such, the force that would result in a structural failure
in the Xi-A loudspeaker system will be at least eight times greater than the specified working-load­limit ratings. The safety factor provides a margin of error to accommodate normal dynamic shock
loading, wear and tear on the hardware components, etc.

THE USER MUST NEVER APPLY A LOAD TO AN Xi-A LOUDSPEAKER SYSTEM THAT
EXCEEDS THE WORKING-LOAD LlMIT RATINGS.

There are two independent strength ratings that, together, give a complete description of the
overall structural performance capabilities of any Xi-A loudspeaker system:

1. The working-load-limit rating for each individual rigging point; which is a function of the
rigging track mounted on the enclosure combined with the specified quick-release rigging
hardware. This rating varies as a function of the angle of pull.

2. The working-load-limit rating for the overall enclosure; which is a function of the combined
forces from multiple rigging points simultaneously acting on the enclosure as a whole. This rating
is independent of the rigging pull angles.

ELECTRO-VOICE® Xi-A Rigging Manual 10

WHEN SUSPENDING ANY Xi-A LOUDSPEAKER SYSTEM OVERHEAD, THE
WORKING-LOAD LIMIT MUST NEVER BE EXCEEDED FOR EACH INDIVIDUAL
RIGGING POINT, AND THE WORKING-LOAD LIMIT MUST NEVER BE
EXCEEDED FOR THE OVERALL ENCLOSURE.

The user must be aware of both of the above working-load-limit ratings at all times. An Xi-A loud­speaker system is only as strong as its weakest link. In most applications, it is usually the case
that one of the working-load limits will be approached sooner than the other. For example, if only
two rigging points are employed, the weakest link will always be the individual rigging points and
the working-load limit for the individual rigging points will always be the dominant factor If, how­ever, four rigging points are used, the weakest link may be either the overall enclosure or the
individual rigging points depending on the angles of pull on the rigging points. The individual
rigging points on each Xi-A loudspeaker system have two working-load-limit ratings, one when
used with a double-stud ring fitting (as used on the GS-1B, LS-1B, LS-2B, LS-3B and RS-1B
rigging accessories), and one when used with a single-stud fitting (as used on the RS-2B rigging
accessory). Two working-load-limit ratings are required because the double-stud and single-stud
fittings have different strength ratings. In addition, those strength ratings will vary with the angle of
pull relative to the surface on which the rigging track is mounted. There is only one working-load­limit rating for the overall enclosure of each Xi-A loudspeaker system, and that rating is indepen­dent of the angles of pull. Specifically, the flying Xi-1191AF, Xi-1183A, Xi-1153A, Xi-2181AF, Xi­2153A, Xi-1122MHA, and Xi-2122MHA loudspeaker systems have the following strength ratings.
When used with double-stud fillings (as used on the GS-1B LS-1B, LS-2B, LS-3B and RS-1B
rigging accessories), the working-load limit rating of each individual rigging point is 500 pounds at
a pull angle of 0° (i.e., perpendicular to the surface on which the track is mounted), 437 pounds at
a pull angle of 45° and 375 pounds at a pull angle of 90° (i.e., parallel to the surface on which the
track is mounted). When used with single-stud fittings (as used on the RS-2B rigging accessory),
the working-load-limit rating of each individual rigging point is 250 pounds at any pull angle. The
working-load-limit rating of the overall enclosure is 1,000 pounds. Electro-Voice insists that the
user must never apply a load to any Xi-A flying loudspeaker system that exceeds the working-load
limit rating of either the individual rigging point or the overall enclosure. The strength ratings of the
flying Xi-1191AF, Xi-1183A, Xi-1153A, Xi-2181AF, Xi-2153A, Xi-1122MHA, and Xi-2122MHA loud­speaker systems are summarized in Figure 4.1a. Specifically, the flying Xi-1122A, Xi-1152A, Xi­1123A and Xi-2123A loudspeaker systems have the following strength ratings. When used with
double-stud fittings (as used on the GS-1B LS-1B LS-2B, LS-3B and RS-1B rigging accessories),
the working-load limit rating of each individual rigging point is 500 pounds at any pull angle. When
used with single-stud fittings (as used on the RS-2B rigging accessory), the working-load-limit
rating of each individual rigging point is 250 pounds at any pull angle. The working-load-limit rating
of the overall enclosure is 750 pounds. Electro-Voice insists that the user must never apply a load
to any Xi-A flying loudspeaker system that exceeds the working-load limit rating of either the
individual rigging point or the overall enclosure. The strength ratings of the flying Xi-1122A, Xi­1152A, Xi-1123A and Xi-2123A loudspeaker systems are summarized in Figure 4.1b. All associ­ated mechanical components used with any Xi-A flying system (shackles, chains, hoists, wire-rope
slings, nylon and/or polyester slings, etc.) should be load rated for overhead lifting. All load-rated
hardware will typically have its load rating displayed on each piece in a visible location. Typical
ratings are denoted as the static-working load (SWL), or the working-load limit (WLL). These
ratings generally assume a safety factor of 5:1; however, the user should consult the hardware
manufacturer to confirm the rating. Occasionally, the load rating is given as the ultimate-break

ELECTRO-VOICE® Xi-A Rigging Manual11

strength. This requires the user to calculate the safety factor directly for a given load. The actual
safety factor for a given load is defined as the ratio of the ultimate-break-strength rating of a
mechanical component to the actual load applied to that component. Electro-Voice suggests that
the user maintain an overall safety factor of at least 8:1 when implementing an Xi-A flying system.
In other words, the ultimate break-strength of each of the mechanical components in the system
should be at least eight times greater than the actual force applied to those components. This
includes the Xi-A enclosures, the rigging-strap assemblies, the grid the hoist and all other me­chanical components and hardware. The working-load limits discussed throughout this manual for
the strength of the Electro-Voice Xi-A enclosures rigging hardware, and the GS-1B, LS-1B, LS-2B,
LS-3B, RS-1B and RS-2B rigging accessories are based on an 8:1 minimum safety factor. Where
local regulations require safety factors greater than 8:1, Electro-Voice insists that the user must
meet the required safety factor. Where local regulations permit safety factors less than 8:1,
Electro-Voice still insists that the working-load limit of the Xi-A enclosures/rigging hardware, and
the GS-1B, LS-1B, LS-2B, LS-3B, RS-1B and RS-2B rigging accessories never be exceeded.

4.2 Special Safety Considerations for Xi-A Loudspeaker Arrays

The techniques discussed in Chapter II for constructing arrays may be expanded upon to create
different arrays utilizing different combinations of Xi-A loudspeaker systems, as long as a sufficient
safety factor is maintained. The user is reminded that the top cabinet in an array supports the
weight of all the cabinets hung beneath it, and that the weight distribution between the rigging
points will depend on the exact configuration. For example, the center of gravity of the Xi-1152A
loudspeaker system is not perfectly centered but rather shifted slightly towards the high-frequency
side of the box. As a result, when an Xi-1152A is hung sideways (i.e., with the cabinet oriented so
the rigging track is on the sides), the load on the rigging strap on the high-frequency side of the Xi­1152A system would be slightly higher than the load on the horn/compression-driver side. On the
other hand, the load would be distributed equally between the two rigging straps at the top of a
column of Xi-1152A systems hung with the enclosures oriented with the rigging track on the top
and bottom. The weight distribution of any Xi-A array can be calculated with the information
presented in Figure 2.2. Readers unfamiliar with the process of calculating load distributions
should consult the list of references in Appendix B.2 that cover the topics of rigging and
engineering mechanics. When arrays are constructed with columns of Xi-A systems oriented with
the rigging tracks on the top and bottom of the enclosures the rigging straps between the
enclosures will not hang straight down with a 0° vertical angle if the center-to-center spacing of the
rigging attachment positions are different from the bottom of one cabinet to the top of the cabinet
immediately beneath it. The rigging straps will deviate from a 0° vertical angle when trapezoidal
cabinets are employed, or cabinets of differing size are mixed in the same column. These vertical­angle differences will result in forces (i.e., tension loads) of the top cabinets (including the top
rigging straps). However, if the rigging straps throughout the array are at unusual and or extreme
angles, the worst-case forces in an array may occur somewhere other than the top rigging­attachment point of the top cabinets.

Attention: Array details and rigging configurations will affect the load on the
loudspeaker systems, the rigging straps and all associated rigging hardware. The
user is responsible for determining the loads on all of the mechanical components
throughout the loudspeaker array, and for ensuring that the working-load limits and
resulting safety factors are not exceeded. A qualified structural engineer should be
consulted to evaluate the design.

ELECTRO-VOICE® Xi-A Rigging Manual 12

Figure 4.1a:

Working-Load Limit Strength Rating for Xi-1153A, Xi-1183A, Xi-2153A,

Xi-1191AF, Xi-2181AF, Xi-1122MHA, and Xi-2122MHA

Figure 4.1b:

Working-Load Limit Strength Rating for Xi-1122A, Xi-1152A, Xi-1123A,

and Xi-2123A

ELECTRO-VOICE® Xi-A Rigging Manual13

4.3 Special Safety Considerations for Rigging Strap Assemblies

4.3.1 Redundant Att achment Points

As an added safety measure, it is suggested that the user install a second set of grid straps from
the top rigging points of the top cabinets in an array back to the grid (or building structural
supports). These redundant safely straps can be secured to an open section of rigging track next
to the primary grid straps. The safety straps should have as little slack as possible (less than one
inch is preferable).

4.3.2 Special Considerations for Polyester Webbing

The GS-1B, LS-1B and LS-2B utilize polyester webbing in their construction. The user is
cautioned, however, that in certain permanent installation applications, the polyester material may
not meet local fire regulations. The user is also cautioned that polyester material will deteriorate
with extended exposure to ultraviolet light (direct sunlight) or to hot, dry environments, resulting in
reduced strength capability. In such instances, wire rope or chain assemblies must be substituted.

4.4 Special Safety Considerations for Grid & Building Structural Supports

When suspending loudspeaker arrays from grids or building supports the associated rigging
hardware employed (i.e., rigging straps, slings, chains, wire-rope assemblies, chains, etc.) may
not hang at a 0° vertical angle. These vertical angle differences will result in forces (i.e., tension
loads) in that rigging hardware that are greater than the weight suspended below. These
increased forces must be taken into account when evaluating the load on the mechanical
components and the safety factor of an array. The greater the angle difference from the 0°
vertical, the greater is the increase in force above what it would be if the straps were at 0°. Any
users unfamiliar with the process of calculating the increased load as a function of lifting angles
should consult the list of references in Appendix B.2 which cover the topics of rigging and
engineering mechanics.

Attention: Array details and rigging configurations will affect the load on the building
structure, the grids, the loudspeaker systems, the rigging straps and all associated
rigging hardware. The user is responsible for determining the loads on all of the
mechanical components throughout the loudspeaker array, and for ensuring that the
working-load limits and resulting safety factors are not exceeded. A qualified
structural engineer should be consulted to evaluate the design.

ELECTRO-VOICE® Xi-A Rigging Manual 14

V. Rigging Inspection, Maintenance and Precaution

5.1 Xi-A System Component s

5.1.1 Xi-A Loudspeaker Systems

Prior to each use, inspect the loudspeaker enclosures for any cracks, deformations, missing or
damaged components that could reduce enclosure strength. Inspect the track and bracket
assemblies on the enclosures for any cracks, deformations, missing or loose screws which could
reduce the flying hardware strength. Replace any loudspeaker systems that are damaged or
missing hardware. Never exceed the limitations or maximum recommended load for the Xi-A
systems.

5.1.2 Rigging Strap Assemblies

Prior to each use, inspect the webbing for cuts abrasion, tears, knots, chemical damage, burns
and broken stitches that could reduce rigging-strap assembly strength. Inspect the rigging fittings
and hooks for any cracks, burrs, deformations, or missing or damaged components that could
reduce strap assembly strength. Replace any rigging-strap assemblies that have damaged
webbing, or damaged or missing hardware. Always double check that each fitting on each of the
rigging-strap assemblies is securely locked into position in the track on the Xi-A enclosures and
that the safety locking pin is engaged before lifting.

5.2 Associated Hardware

5.2.1 Grid Assembly

Prior to each use, inspect the grid assembly and associated hardware for any cracks,
deformations, broken welds, corrosion, or missing or damaged components that could reduce the
grid assembly strength. Replace any damaged grid assemblies. Never exceed the limitations or
maximum recommended load intended for grid assembly design.

5.2.2 Chain Hoists

Prior to each use, inspect the chain hoist and associated hardware (including motor, if applicable)
for any cracks, deformation, broken welds, corrosion, or missing or damaged components that
could reduce the hoist strength. Replace any damaged chain hoists. Never exceed the limitations
or maximum recommended load specified by the hoist manufacturer. Always raise and lower the
load slowly and evenly, avoiding any rapid changes in speed or shifting loads that could result in a
sudden jolt to the suspended system.

5.2.3 Building Structural Supports

Prior to each use, the strength and load-bearing capabilities of the building structural supports
should be evaluated and certified by a professional engineer as being adequate for supporting the
intended rigging system (including the loudspeakers, grids, chain hoists and all associated
hardware). Prior to each use, inspect the building structural supports for any cracks, deformation,
broken welds, corrosion, or missing or damaged components that could reduce the structural
strength. Damaged building structural supports should be replaced or repaired and re-certified by
a professional engineer.

ELECTRO-VOICE® Xi-A Rigging Manual15

5.2.4 Mechanical Components

Prior to each use, inspect all mechanical components (chain, wire ropes, slings, shackles, hooks,
fittings, etc.) for any cracks, deformation, broken welds, slipping crimps, fraying, abrasion, knots,
corrosion chemical damage, loose screws, missing or damaged components which would reduce
the maximum strength specified by the component manufacturer. Replace any damaged
mechanical components.

ELECTRO-VOICE® Xi-A Rigging Manual 16

VI. Appendices

Appendix A: Xi-A Rigging Accessories
GS-1B, LS-1B, LS-2B, LS-3B, RS-1B and RS-2B Xi-A Rigging Accessories: These rigging

accessories described throughout this manual are available from:

Sound Manufacturing, Inc.

P.O. Box 1907

Big Bear Lake, CA 92315, USA

[phone]

www .smirigging.com

[e-mail]

Custom Rigging Strap Assemblies: Custom wire rope or webbing rigging strap assemblies that
use the RS-1B and RS-2B fittings may be ordered from:

Sound Manufacturing, Inc.

P.O. Box 1907

Big Bear Lake, CA 92315, USA

[phone]

www .smirigging.com

[e-mail]

General Rigging Supplies: A wide variety of standard and specialty rigging hardware
components for both touring and permanent-installation applications are available from:

Sound Manufacturing, Inc.

P.O. Box 1907

Big Bear Lake, CA 92315, USA

[phone]

www .smirigging.com

[e-mail]

ATM Fly-ware™

21000 S. Wilmington Ave.

Carson, CA 90810 USA

[phone]

www.atmflyware.com

[e-mail]

ELECTRO-VOICE® Xi-A Rigging Manual17

Appendix B
B.1 Acoustical References

A brief list of references covering the topics of acoustics and sound-system design is presented
below:
(1) D. Davis & C. Davis, Sound System Engineering, Howard Sams & Co., Indianapolis, IN
(1987).
(2) J. Eargle, Handbook of Sound System Design, ELAR Publishing Co., Commack, NY
(1989).
(3) G. Davis & R. Jones, Sound Reinforcement Handbook, Hal Leonard Publishing Corp.,
Milwaukee, WI (1989).
(4) L.L. Beranek, Acoustics, American Institute of Physics, Inc. New York, NY (1986).
(5) H.F. Olson, Acoustical Engineering, Professional Audio Journals, Inc., Philadelphia, PA
(1991).
(6) L.E. Kinsler. A.R. Frey, A.B. Coppens, & J.V. Sanders, Fundamentals of Acoustics, John
Wiley & Sons, New York, NY (1980).
(7) D.B. Keele, Electro-Voice, Inc., “What’s So Sacred About Exponential Horns,” presented at the
51St Convention of the AES (May, 1975), preprint #1038.
(8) P.F. Fidlin & D.E. Carlson Electro-Voice, Inc., Comparative Performance of Directional Devices
Used as Concert-Sound Loudspeaker Array Elements,” Journal of the AES (April,

1990).

B.2 Mechanical References

A brief list of references covering the topics of rigging and engineering mechanics is presented
below:
(1) W.E. Rossnagel, L.R. Higgins & J.A. MacDonald, Handbook of Rigging for Construction
and Industrial Operations, McGraw-Hill Book Company, New York, NY, USA (1988).
(2) A. Jensen & H. Chenoweth, Applied Engineering Mechanics, McGraw-Hill Book Co.,
New York, NY (1983).
(3) J.O. Glerum, Stage Rigging Handbook, Southern Illinois University Press, Carbondale, IL,
USA (1987).
(4) P. Carter, Backstage Handbook, Broadway Press, New York, NY, USA (1988).
(5) Wire Rope Technical Board, Wire Rope Users Manual, American Iron and Steel Institute,
Stevensville, MD, USA (1985).
(6) ATM FIy-Ware™, ATM Fly-Ware™ Catalog of Rigging Hardware and Supplies, ATM
Group, Inc., Carson, CA (1996).
(7) Broderick & Bascom Rope Company, Rigger’s Handbook, Sedalia, MO, USA (1993).
(8) MacWhite Wire Rope Company, Catalog of Tables, Data and Helpful Information,
Kenosha, WI, USA (1991).
(9) Acco Chain & Lifting Division, Chain Sling User’s Manual, Acco Corporation, York,
PA, USA (1992).
(10) Newberry, W.G., Handbook for Riggers, Newberry Investments Company, Calgary,
Alberta, Canada (1989).

ELECTRO-VOICE® Xi-A Rigging Manual 18

U.S.A. and Canada:

For customer orders, contact the Customer Service department at:
800/392-3497 Fax: [phone]
For warranty repair or service information, contact the Service Repair Department at:
800/685-2606
For technical assistance, contact Technical Support at:
866/78-AUDIO
Specifications subject to change without notice.

All Other International Locations:

952-884-4051 Fax: [phone]

www.electrovoice.com 

Printed in U.S.A
© Telex Communications, Inc. 10/2004

Part Number 534993 Rev B

Telex Communications, Inc. 

www.telex.com

ELECTRO-VOICE® Xi-A Rigging Manual