Your performance venues may use a variety of audio and video equipment, such as mixers, amplifiers, loud speakers, outboard gear, microphones, computers, projectors, and external dowers, etc.
Like lighting operations, there are significant exposures while installing, maintaining, and storing audio and video equipment. You may be exposed to hazards such as fall from heights while installing speakers, injury sustained from falling equipment, or back injuries from lifting heavy equipment. An added hazard may result from the decibel level generated by the speakers and amplifiers.
It is important to review the rigging and safe lifting guidelines in the Set Construction section. In addition, the USF STAGES Code of Safe Practices Matrix identifies the applicable theater codes of safe practices you are required to read for audio operations.
Your supervisor will train you on the proper grounding requirements of the audio equipment. Proper grounding will help eliminate a ground loop that can potentially damage the equipment and may also result in electrical shock. The best thing to do is avoid electrical shock by following safe electrical work practices including lockout/ tagout. For additional information regarding lockout and tagout, read the Lockout/Tagout/Blockout section in the Set Construction chapter and the Code of Safe Practice on lockout/tagout/blockout, and consult your Campus Lockout/ Tagout/Blockout Program for more information. For additional information on basic electrical safe work practices, review the electrical safety code of safe practices to understand why and how electrical shock can be so dangerous.
Risks of Falling from Heights
The procedures for hanging audio equipment may require you to work from significant heights on catwalks, scaffolding, tension grids, aerial work platforms, ladders or other elevated work surfaces. Fall exposures must be identified in the planning stages and where necessary, appropriate fall protection measures (guardrails, fall arrest gear, etc.) need to be in place and used. Employees and students must be trained on potential fall exposures and the presence or use of required fall protection. Supervisors must ensure employees are following all safety requirements. In addition to direct training, several codes of safe practices that address fall protection must be reviewed.
Suspended and Stand-Mounted Audio Equipment
Overhead speaker units can cause severe injuries if not suspended properly. Supervisors will train employees on how to properly install and rig the suspended units. Ensure swags for flown cables are marked with caution tape and placed at a safe height. The cable should be placed at a height that will clear moving scenery and also be a safe distance off the deck. Tripods can present trip/fall and falling object hazards. Supervisors will train employees regarding proper tripod placement to ensure they are placed to reduce trip/fall hazards and properly installed to prevent tip-over incidents.
High noise levels generated during rehearsals and productions can result in hearing damage and hearing loss for the performers, crew, and orchestra. Conduct sound level testing when planning high noise level events, and provide appropriate hearing protection devices when the planned noise levels reach an 8-hour time weighted average of 85 decibels. Contact your Campus EH&S office for assistance in evaluating the hazards of high noise levels.
Video and Projection Equipment
The use of video and projection equipment may involve placing computer towers on the tension grid or catwalks, running Cat5 (Ethernet) cables, placing heavy projectors in elevated positions, mounting bright lights, mounting theatrical dowsers at elevated heights, or installing projection screens. The use of proper body mechanics is important when lifting heavy equipment. Fall protection may be necessary when working in elevated positions. The use of ladders is common. It is important that Performing Arts Codes of Safe Practice for electrical safety, fall protection – catwalk safety, fall protection – portable ladder, fall protection – tension grid, lockout/tagout, and material handling – safe lifting and moving materials are reviewed and followed as appropriate.
Cable management for audio equipment poses the same hazards as cable management for lights. Audio cabling includes the signal carrying cables, as well as, the power cables. The same cable management steps used for lights apply to audio cables: 3 See the code of safety practices regarding fall protection – trigger heights.
Create a circuiting diagram for the theater indicating the location of all the audio/visual equipment.
Add extra sheets as needed to plot the sound board.
Use the circuiting diagram to plan the equipment locations. Use gaffers tape to label the circuit number at both ends of each cable.
Use the shortest cables possible to eliminate hanging loops that will tangle.
Provide sufficient slack in the cable to allow for position adjustments.
Group cables in parallel lines and use Velcro rip-ties, theatrical cord, or tie line (glazed or unglazed) to keep them organized. The use of Velcro rip-ties, theatrical cord, or tie line has several advantages:
a. you need not replace the Velcro rip-ties, theatrical cord, or tie line (glazed or unglazed) each time you need to add or remove a cable from the group
b. the cable are not at risk of being cut as they are when you have to cut off a zip-tie
c. the risk of injury from the sharp edge of a trimmed zip-tie is eliminated
d. the job is not disrupted by the search for a replacement tie as can happen when using zip-ties that cannot be reused
e. rip-ties, cord, and tie line generally cannot be pulled so tight they damage the cables
Never wrap cables around support beams or catwalk guardrails.
Use re-closable J hooks and/or Velcro cable straps to support cables that must be suspended from one point to another.
Coil extra lengths of cable, and use Velcro rip-ties to keep the coil stable.
Use cable guards where the cables must cross a foot-traffic area. If practical, use a cable guard that is equipped with yellow or orange stripes to alert cast and crew of the trip hazard.
Inspection, Maintenance, and Storage
Regular inspection and maintenance will significantly reduce potential electrical malfunctions. Training is required for any employee responsible for inspecting or maintaining audio and video equipment.