[David I Am]

I don’t think you’re considering Viscosity Antonio! In the milliseconds of note valve open/attack, if the air has to move from further away than it would were it pushed by the bladder, it wouldn’t get there in time.

I suspect this is a really dynamic effect – its not visually visible to human eye, you probably could get more of an idea what’s going on if you took high speed footage of how the part of the bladder closest to the opening momentarily dips as the note opens – supplying more air volume to the opening than the pressure front alone would permit…