Air is flowing in a laminar way when the air molecules travel in an orderly way. The flow is not too strong and not too weak. If you overblow, the air becomes turbulent; you feel that you have to fight with instrument’s resistance. If the air stream is too weak, then there is not enough energy to generate a carrying sound.
(Check if this is a correct theory)
- Aim for non-turbulent air
- When you “overblow” your airstream probably has turned turbulent