No secure ad-hoc network with Yosemite?

iMac (late 2009) OSX 10.10.3 iPads (a 1 and a 2) iOS 8.? --- I am a retired IT engineer playing at being a DJ/VJ. That means I'm often in a room with lots of folks with cells and iPads. Before Yosemite, I was creating ad-hoc nets at my gigs and connecting my iPads to my iMac. It was relatively comfortable that I wouldn't have to worry about anyone screwing around with my systems, audio/video/DMX lighting. I am getting ready to do some gigs and while checking my system, I realized there is no longer a Create Network option on my Wi-Fi menu. And from what I'm reading here, it doesn't appear I can even create one. Is this correct?