Yeah..I'm wondering about that choked down tube ending as well...or is it just to get the velocity up and that supposed to have equal lift at the wand lips? I'm not sure thats a good idea...
But maybe....if we put in a choker at every 50' section of a hose run to speed up the airmovement maybe that would work too? kinda like putting in a 1.5" connector in your 2" vac line at every connection.. anybody tried that before? This maybe the stupidest thing I ever thought of...I need coffee this morning.