Ok I'm guess I'm gonna have to be that guy. I'm far from an expert but that is not the correct air! Maybe it's the video but that doesn't sound like "hot" air. The key to blowing a duck call is using that crisp air. Like fogging up a window! You shouldn't have any cheek movement as it comes from ur diaghram! And feed call I'm more of the tic tic tic! As the tica tica is what ducks do in the air when they are flying or maybe a marsh with thousands of mallards. I don't meant to offend the original poster but duck calling isnt that easy! Yes it is easy but the problem is that it's so easy it's hard for lots of people! One day after LOTS of practice it will click! But take my advice as is! Sorry if offended original post but I feel like his video wasn't technically correct!
I stopped by echo calls one day over in Ark. I use their calls. we went over duck calling and they corrected my feed call. I was a tic tic and tica tica AND a Ka ka dude one time. All belly, hot air. They taught me to (and this is one time when you want more air from above) to use my mouth air more and say a diga dig digga dig sound. It gives it that guttural sound that real ducks sound like when their feeding.