User manual ELECTRO-VOICE XI-A

[. . . ] Xi-A Series Loudspeaker System Flying Manual ELECTRO-VOICE® Xi-A Rigging Manual Table of Contents 0. Rigging-Safety Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 1 The Flying 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. [. . . ] Box 1907 Big Bear Lake, CA 92315, USA (909) 878-9104 www. smirigging. com smiller@smirigging. com ATM Fly-wareTM 21000 S. Carson, CA 90810 USA (310) 834-5914 www. atmflyware. com clientservice@atmflyware. com 17 ELECTRO-VOICE® Xi-A Rigging Manual 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, Sound System Engineering, Howard Sams & Co. , Indianapolis, IN (1987). Eargle, Handbook of Sound System Design, ELAR Publishing Co. , Commack, NY (1989). [. . . ]