User manual ELECTRO-VOICE 12WK

[. . . ] 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] 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. 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 Figure 2. 6a: Adding a Bottom Enclosure Affects the Top Enclosure Angle Rigging is on the Top or Bottom Figure 2. 5b: Enclosure Oriented so the Rigging is on the Sides 9 Figure 2. 6b: Change the Rigging Attachment Point on Top Enclosure to Readjust Top Enclosure Angle ELECTRO-VOICE® Xi-A Rigging Manual 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-WareTM 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 InstallTM (Xi-A) loudspeaker systems overhead is expressly the responsibility of others. IV. [. . . ] 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. Box 1907 Big Bear Lake, CA 92315, USA (909) 878-9104 www. smirigging. com smiller@smirigging. com 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. Box 1907 Big Bear Lake, CA 92315, USA (909) 878-9104 www. smirigging. com smiller@smirigging. com 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. [. . . ]