While not as great a spread as you are looking for I use a boom arm that I unscrewed the counter weight from. Each end is threaded 5/8-27 and with a couple of Shure A53s screwed on, center of mount to center of mount distance is a fraction under 36". Got the boom arm for cheap from my local independent music store since the rest of the stand had been damaged in shipping. Check a local independent if you have one or one of the chains (GC, Sam Ash etc) if no indepedents in your area. A different brand may have just the length you want.