Tom, the vast majority of my calling for bobcat has been in the daytime for photography.
I expect that many callers not specifically pursuing bobcat a). call it quits way too soon on their stands, and b). don't know the difference between what constitutes a good bobcat stand and a good coyote stand.
I'm not looking for a bobcat to cross wide open spaces, or draw them vast distances, but am rather trying to pull them out of pockets of dense brushy, bouldery, or oak savannah areas where I've scouted them holing up. Calling them "cold" is mostly a time-waster, IMO. I usually start scouting wherever theres a confluence of features like a creek bottom and several intersecting edges or game trails. Recent scent posts (scat piles), scraps of rabbit fur or feather piles are mostly what I'm looking for. Incidentally, bobcats have a habit of laying up by day where they have an exceptional vista or lookoout over the terrain, which can be quite the challenge for how to stalk into your stand undetected, so the scouting is often as much about this.
Wherever they share their territory (or margins) with coyote and/or ML also in residence, I note that they don't seem to like to be too far from the haven of dense timber or heavy brush. Knowing this, I don't set up specifically for bobcats on one side of a large meadow looking across it for bobcats exiting the woods on an obvious game trail and coming to the call in a beeline. Neither do I expect to see them skirting around edge of a meadow on the other side as I might look for coyote to do. Whenever I have called bobcat in these situations, they've almost invariably come in the back door. Which seems a bit odd considering that bobcats will often be seen mousing in the wide open and you can sometimes stalk up fairly close when they are so occupied (when focused on abundant gophers, mice or voles in the middle of a field, however, bobcats will only rarely be deterred by a distant lipsqueak, unlike a coyote.) If I happen to jump a bobcat that's out mousing, I've found it best to make a mental note, but save that particular cat for another day's calling. Otherwise I'm just educating it.
I'll throw in with the crowd that experiences bobcat responding much more stealthily and slowly than coyote or fox--often, though not always, using every available terrain feature and patch of shade to try remain out of sight until relatively close. Then they'll sit down at about 30-50 yards out, glassing the scene until they're either comfortable (when they may stroll in and right up on a speaker at 30-45 minutes) or further intrigued (induced to stalk up practically to your boots if you're squeaking and well camo'd, and sometimes even when you're not).
Even if patient, it can be darn hard to spot them when they hang up and park themselves to survey the scene, usually behind a screen of something. As often as not you'll get a glimpse of motion 100-200 yards out, and then they just fade away without necessarily spooking or anything, just being wildcat stealthy. I'm reasonably certain that I call in about 10 bobcat to every one I got a good look at.
Helps to set up an ecaller in the middle of a small clearing not more than 50 feet away from my stand, in plain view rather than behind a big clump of brush. Otherwise a cat may too easily stalk in and stealth back out and I'd never be the wiser. Remote ecallers really have their use here, though a long speaker cord is just as productive for me a the close distances I'm working with (just not as convenient).
Also, if I've been blasting all the ears of the forest with a rabbit distress at volume in bobcat-rich territory, at the first indication of jays razzing a cat, or if lucky a flash of rosette-spotted flank, I'll switch to a super high-pitched rodent sound of some sort, or lipsqueak (or recording). Coaxer sounds don't travel all that far, but nor do I figure a bobcat will travel far either. Here I can't reasonably expect a bobcat to come more than 300 yards to the call. And it will likely take 45 minutes or longer for one to show up from that distance.
Even when you know you've got one stalking in, you've got nervous quail pweets or chattering chippies tipping you off to exactly where they are... they can still sometimes slip in to twenty feet and back out again, sight unseen. And it's still a rush and a challenge, almost 20 years into specifically targetting them...
LionHo