I'm a stickler for using stereo mounts for setting up pairs of microphones or grouping two mics on an amp when recording, and I am usually completely unhappy with how all these stereo bars and mounts are designed. My favorite for years has been a simple one K&M made, with two adjustable arms and two 5/8-inch threaded bolts to hold the mic clips. These bolts (or whatever you wish to call them) were not too deep, so they fit into every mic clip or mount I had. Then K&M switched to making only Europe-style 3/8-inch threaded stereo bars and I had to contend with stupid adapter pieces in order to use my much more common 5/8-inch clips and mounts. These adapters usually got stuck in the mic clips or fell off onto the floor. They also take up more room vertically, so they don't fit some clips as they will never reach a point where the clip and stereo bar base fit snugly. Many stereo bars – even ones featuring 5/8-inch threads – have this exact same issue, with mic clips never fitting snugly. When I grab a stereo bar with these problems and spend 10 minutes trying to figure out how to keep my mics in place I lose my f-ing marbles.
Described as a "dual microphone utility mount," Royer's new FlexBar mic holder is a step beyond the typical stereo bar. Two L-shaped arms hold each mic, and then meet on a T-shaped mount where a strong clamp and a long "hole" allows the mounts to swing nearly 360 degrees around (while remaining on the same plane). The bars are labeled with engraved gradient markers in centimeters for resetting or accuracy. The T-shaped mount attaches to a 5/8-inch mic stand or boom and has another strong clamp with locking teeth that allows over 180 degrees of movement on the same plane as the arms. It's all cast aluminum, sturdy, and I was able to make it hold in place even with some goofy angles going on!
Best uses for FlexBar? I can get a quick X/Y and ORTF stereo mic pair set up. As I'm always double mic'ing electric guitar amps, this makes my job easier and faster. Top and bottom snare mic'ing is now easy via only one stand, and the L-shaped arms ensure ease of placement. Setting up a nice figure-8 Blumlein pair (top and bottom), especially with two Royer R-121 ribbon mics [Tape Op #19], is a breeze, though larger tube mics with base mounts won't usually fit within the 12- to 14-inch spread of the arms. Mic'ing up a singer/acoustic guitarist with one stand with this quick flexibility just got easier as well.
Between the FlexBar and the Shure A27M [see review below], I've now got several ways to set up stereo or dual mics so much quicker and much more sturdily than I used to, and that's all I ever wanted!