142 the other end 146 of threaded pipe hanger 42 is threaded into central aperture 38 of suspension member interface 20 so that adjustable bracket 12 and an attached projector 94 are suspended from the overhead structure 130 by threaded pipe hanger 42 a tamper resistant set screw 148 may be threaded into tapped hole 150 to stake threaded pipe hanger 42 in position and inhibit tampering or theft accomplished through unthreading of pipe hanger 42 similarly pipe hanger 42 may be fixed within pipe nipple 142 by a tamper resistant setscrew 151 inserted through tapped hole 152 alternatively particularly where the structural connection of pipe hanger 42 is above a concealing structure such as a suspended ceiling pipe hanger may be fixed to pipe nipple 142 by welding or with a fastener 152 a inserted through a hole 153 drilled through the threaded connection of pipe hanger 42 and pipe nipple 142 as an alternative a plurality of suspension members 14 in the form of rod hangers 45 may be used to suspend adjustable bracket 12 and attached projector 94 as depicted in fig6 and 7 again channels 136 are arranged spanning parallel structural members 131 channels 136 have apertures 154 for receiving an end 156 of each rod hanger 45 the rod hangers 45 may be formed from threaded rod stock each rod hanger 45 is attached to the channel.