I agree........that is normal.
Speakers move air. Especially subwoofers. Because of size, or placement of the speakers, will determine if you actually feel the air, or not. You also won't feel it as well, from a down firing sub. I have a JBL PSW1200 sub. In the house we moved from, I had it behind the sofa. When I first watched "The Butterfly Effect", and those moments when there was the
sudden blast of bass, the blast of air came through the sofa, and hit us in the back, so we felt the effect. The first one was unexpected, and about knocked us off the sofa.
It was very enjoyable,
feeling the effect, like that! It was sorta like having the Force Feedback feature on a joystick, or steering wheel, for a game.......
Enjoy!