Sorry guys. This is another example of the plethora of bad information being spread around by misinformed "experts" who badly need to retake their high school physics.
I would assume you would be referring to my post, as I was the only after the initial question... (finished 2 years of university physics, 1 year of university chem...) what part don't you agree with? here is an example for you. set up a aquarium, then put a bubbler in it and blow bubbles through the line. try blowing when the bubbler is at the bottom, and then try when it is near the top of the tank. it is MUCH easier when it is at the top, for your average 29 gallon tank it is quite difficult to actually get a decent stream of bubbles when the outlet is at the bottom.
your muffler pressure is you blowing into the tank. the overall effect is the pressure is the same when the tank is near empty, but when it is full the pressure the muffler exerts is decreased, much the same as how you aren't able to blow as many bubbles through the aquarium when the outlet is at the bottom. I would like to hear why or how this system does not work as I have outlined...